***Useful Information for Apprentices***

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“ General Health and Safety at Work “

Question 1.1
What do the letters CDM stand for ?
A: Control of Demolition and Management Regulations
B: Control of Dangerous Materials Regulations
C: Construction (Demolition Management) Regulations
D: Construction (Design and Management Regulations ) Answer: D )
Question 1.2
Identify one method of enforcing regulations that are
available to the Health and Safety Executive:
A: Health Notice
B: Improvement Notice
C: Obstruction Notice
D: Increasing insurance premiums
Answer: B Improvement notices require action to achieve standards which meet health and safety law :
Question 1.3
What happens if a Prohibition Notice is issued by an
Inspector of the local authority or the HSE ?
A: The work in hand can be completed, but no new work started
B: The work can continue if adequate safety precautions are put in place
C: The work that is subject to the notice must cease
D: The work can continue, provided a risk assessment is carried out,
Answer: C The work covered by a prohibition notice must cease until the identified danger is removed.
Question 1.4
Health and Safety Executive Inspector can ?
A: Only visit if they have made an appointment
B: Visit at any time
C: Only visit if accompanied by the principal contractor
D: Only visit to interview the site manager
Answer: B Inspectors have a range of powers, including the right to visit premises at any time.
Question 1.5
A Prohibition Notice means:
A: When you finish the work you must not start again
B: The work must stop immediately
C: Work is to stop for that day only
D: Work may continue until the end of the day
Answer: B The work activity covered by the prohibition notice must cease, until the identified danger is removed ,
Question 1.6
In what circumstances can an HSE Improvement Notice be issued ?
A: If there is a breach of legal requirements
B: By warrant through the police
C: Only between Monday and Friday on site
Answer: A Improvement notices require action to achieve standards which meet health and safety law .
Question 1.7
What is an “Improvement Notice”?
A: A notice issued by the site principal contractor to tidy up the site
B: A notice from the client to the principal contractor to speed up the work
C: A notice issued by a Building Control Officer to deepen foundations
D: A notice issued by an HSE/local authority Inspector to enforce compliance with health
Answer: D Improvement notices require action to achieve standards which meet health and safety law .
Question 1.8
If a Health and Safety Executive Inspector issues a“ Prohibition Notice”, this means that:
A: the Site Manager can choose whether or not to ignore the notice
B: specific work activities, highlighted on the notice, must stop
C: the HSE must supervise the work covered by the notice
D: the HSE must supervise all work from then on
Answer: B Prohibition notices are intended to Stop activities which can cause serious injury.
Question 1.9
Which one of the following items of information will you find on the Approved Health and Safety Law poster?
A: Details of emergency escape routes
B: The location of the local HSE office
C: The location of all fire extinguishers
D: The identity of the first aiders
Answer: B The poster also lists the persons with health and safety responsibilities, but not first aiders.
Question 1.10
Who is responsible for signing a Company Safety Policy ?
A: Site Manager
B: Company Safety Officer
C: Company Secretary
D: Managing Director
Answer: D The Health and Safety at Work Act requires the most senior member of management to sign the health and safety policy
statement.

Question 1.11
Which one of the following must be in a company’s written Health and Safety Policy:
A: Aims and objectives of the company
B: Organisation and arrangements in force for carrying out the health and safety policy
C: Name of the Health and Safety Adviser
D: Company Director’s home address
Answer: B This requirement appears in the Health and Safety at Work Act.
Question 1.12
Employers have to produce a written Health and Safety Policy statement when:
A: A contract commences
B: They employ five people or more
C: The safety representative requests it
D: The HSE notifies them
Answer: B This is a specific requirement of the Health and Safety at Work Act.
Question 1.13
Companies employing five or more people must have a written Health and Safety Policy because:
A: The principal contractor gives them work on site
B: The HSAWA 1974 requires it
C: The Social Security Act requires it
D: The trade unions require it
Answer: B
Question 1.14
What do the letters HSC stand for ?
A: Health and Safety Contract
B: Health and Safety Consultant
C: Health and Safety Conditions
D: Health and Safety Commission Answer: D
Question 1.15
Which ONE of the following statements is correct ? The Health and Safety Executive is:
A: a prosecuting authority
B: an enforcing authority
C: a statutory provisions authority
Answer: B The Health and Safety Executive enforces health and safety legislation.
Question 1.16
The Health and Safety at Work Act requires employers to provide what for their employees?
A: Adequate rest periods
B: Payment for work done
C: A safe place of work
D: Suitable transport to work
Answer: C This is a specific requirement of Section 2 of the Health and Safety at Work Act.
Question 1.17
The Health and Safety at Work Act 1974 and any regulations made under the Act are:
A: Not compulsory, but should be complied with if convenient
B: Advisory to companies and individuals
C: Practical advice for the employer to follow
D: Legally binding Answer: D
Question 1.18
Under the Health and Safety at Work Act 1974, which of the following have a duty to work safely?
A: Employees only
B: The general public
C: Employers only
D: All people at work
Answer: D Employers, employees and the self-employed all have a duty to work safely under the Act.
Question 1.19
What is the MAXIMUM penalty that a Higher Court, can currently impose for a breach of the Health and Safety at Work Act?
A: £20,000 fine and two years imprisonment
B: £15,000 fine and three years imprisonment
C: £1,000 fine and six months imprisonment
D: Unlimited fine and two years imprisonment
Answer: D A Lower Court can impose a fine of up to £20,000 and/or up to six months imprisonment for certain offences. The potential fine in a Higher Court, however, is unlimited and the term of imprisonment can be up to 2 years.
Question 1.20
What do the letters ACoP stand for ?
A: Accepted Code of Provisions
B: Approved Condition of Practice
C: Approved Code of Practice
D: Accepted Code of Practice
Answer: C An ACOP is a code of practice approved by the Health and Safety Commission.

Question 1.21
Where should you look for Official advice on health and safety matters?
A: A set of health and safety guidelines provided by suppliers
B: The health and safety rules as laid down by the employer
C: Guidance issued by the Health and Safety Executive
D: A professionally approved guide book on regulations
Answer: C The HSE is the UK enforcing body and its guidance can be regarded as ‘official’
Question 1.22
Regulations that govern health and safety on construction sites:
A: apply only to inexperienced workers
B: do not apply during ’out of hours’ working
C: apply only to large companies
D: are mandatory ( that is, compulsory )
Answer: D The requirements of health and safety law are mandatory, and failure to follow them can lead to prosecutions.
Question 1.23
Which of the following statements is correct ?
A: The duty for health and safety falls only on the employer
B: All employees must take reasonable care, not only to protect themselves but also their colleagues
C: Employees have no responsibility for Health and Safety on site
D: Only the client is responsible for safety on site
Answer: B The responsibility for management of Health and Safety Act at Work rests with the employer
Question 1.25
Which of the following is correct for risk assessment?
A: It is a good idea but not essential
B: Only required to be done for hazardous work
C: Must always be done
D: Only required on major jobs
Answer: C There is a legal requirement for all work to be suitably risk assessed.
Question 1.26
In the context of a risk assessment, what do you understand by the term risk?
A: An unsafe act or condition
B: Something with the potential to cause injury
C: Any work activity that can be described as dangerous
D: The likelihood that harm from a particular hazard will occur
Answer: D Hazard and risk are not the same. Risk reflects the chance of being harmed by a hazard
Question 1.27
Who would you expect to carry out a risk assessment on your working site?
A: The site planning supervisor
B: A visiting HSE Inspector
C: The construction project designer
D: A competent person
Answer: D A risk assessment must be conducted by a 'competent person’.
Question 1.28
What is a HAZARD ?
A: Where an accident is likely to happen
B: An accident waiting to happen
C: Something with the potential to cause harm
D: The likelihood of something going wrong
Answer: C Examples of hazards include: a drum of acid, breeze blocks on an elevated plank; cables running across a floor.
Question 1.29
What must be done before any work begins ?
A: Emergency plan
B: Assessment of risk
C: Soil assessment
D: Geological survey
Answer: B This is a legal requirement of the Management of Health and Safety at Work Regulations.
Question 1.30
Complete the following sentence: A risk assessment
A: is a piece of paper required by law
B: prevents accidents
C: is a means of analysing what might go wrong
D: isn’t particularly useful
Answer: C Risk assessment involves a careful review of what can cause harm and the practical measures to be taken to reduce the risk of harm.

 

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Re: Useful Information for Apprentices

Question 1.31
Why would your supervisor ask you to read the method statement and risk assessment before you start your next job?
A: He thinks you have got nothing better to do
B: They contain information on how to carry out the job in a safe manner
C: He wouldn’t, he thinks they are a waste of time
D: As someone has taken the time and trouble to write them, you might as well read them
Answer: B The supervisor must, by law, keep workers advised of significant risks, and control measures.
Question 1.32
What do the blue and white health and safety signs tell you?
A: Things you must do
B: The nearest fire exit
C: The hazards in the area
D: Things you must not do
Answer: A Blue and white signs show a ‘mandatory’ requirement.
Question 1.33
What colours are fire exit signs ?
A: Green and white
B: Red and yellow
C: Red and white
D: Blue and white
Answer: A The colours are prescribed in the Health and Safety ( Safety Signs and Signals ) Regulations.
Question 1.34
What is the main colour on a safety sign stating that
you must NOT do something?
A: Blue
B: Green
C: Red
D: Yellow
Answer: C Prohibitory signs are round and feature a black pictogram on a white background with red edging and
diagonal line.
Question 1.35
The Health and Safety (Safety Signs and Signals) Regulations require the colour coding of signs. What
colours are used on a sign indicating a warning, for example "Fork-lift trucks operating”?
A: Blue and white
B: Green and white
C: Yellow and black
D: Red and white
Answer: C Warning signs are triangular and feature a black pictogram on a yellow background with black edging.
Question 1.36
The Health and Safety (Safety Signs and Signals) Regulations require the colour coding of safety signs.
What colours are used on a sign indicating a prohibited activity, for example “No access for pedestrians”?
A: Green and white
B: Red, black and white
C: Blue and white
D: Yellow and black
Answer: B Prohibitory signs are round and feature a black pictogram on a white background with red edging and
diagonal line.
Question 1.37
The Health and Safety (Safety Signs and Signals ) Regulations require the colour coding of safety signs.
What colours are used on a sign indicating a mandatory activity, for example “Safety helmets must be worn
A: Green and white
B: Red, black and white
C: Blue and white
D: Yellow and black
Answer: C Mandatory signs are round and feature a white pictogram on a blue background.
Question 1.38
The Health and Safety ( Safety Signs and Signals ) Regulations require the colour coding of safety signs.
What colours are used on a sign indicating a safe condition, for example “First Aid kit”?
A: Red, black and white
B: Blue and white
C: Yellow and black
D: Green and white
Answer: D Emergency escape and first-aid signs are rectangular or square and feature a white pictogram on a green
background.
Question 1.39
Why should regular inspections of the workplace take place ?
A: To check whether the working environment is safe
B: To check that all employees are present
C: To check that everyone is doing their job
D: To prepare for a visit from an HSE Inspector
Answer: A
Question 1.40
How can you help to prevent accidents ?
A: Don’t report them
B: Know how to get help quickly
C: Report any unsafe conditions
D: Know where the first-aid kit is kept
Answer: C Action to improve safety can only be taken if the risk is known about. Employees have a duty of care to other employees.

Electrotechnical
You should have an understanding of:
• The effects of electric current on the body
• The types of socket outlets used on construction sites
• The need for persons working on electrical systems to be competent to do so
• The use of residual current devices for supplementary protection against electric shock
• Safe isolation procedures when working on electrical systems and equipment
• Only working ‘live’ in exceptional circumstances
• Safe working with optical fibres

Question 10.1
In considering whether to work live a responsible person should
A: carry out a risk assessment
B: only work dead
C: only work live
D: do as the client demands
Answer: A To identify and assess the risks involved and the methods of controlling them.
Question 10.2
The normal procedure for working on electrical equipment should be which one of the following?
A: Dead working
B: Wearing insulated gloves
C: Using insulated tools
D: Live working
Answer: A Dead working should be considered as the norm and work on or near live conductors should rarely be permitted
Question 10.3
Test instruments used for working on electrical systems should:
A: be yellow in colour
B: be less than 10 years old
C: have non-insulated test probes
D: have insulated test probes
Answer: D To protect the user from electric shock whilst using the instrument ie handling the probes.
Question 10.4
Under the Electricity at Work Regulations, live working is considered:
A: as entirely acceptable
B: to be normally permitted
C: only to be allowed in exceptional circumstances
D: never to be allowed
Answer: C Extra controls must be employed, including training, supervision and use of suitable tools and protective equipment.
Question 10.5
Which of the following would you use to replace the fuse in a plug if fuses were NOT available ?
A: A nail
B: A piece of silver paper
C: A bit of wire
D: None of the options mentioned
Answer: D A fuse is often the main safety device in an electrical circuit. A blown fuse must only be replaced by a fuse of the correct type and rating.
Question 10.6
To prove a circuit or equipment is dead after isolation what is the FIRST activity in the sequence of events ?
A: Make sure equipment is not working
B: Check between phase and earth
C: Check proving instrument is working on known live source
D: Check between phase and neutral
Answer: C To prove that the voltage detector (such as a two-pole voltage detector, proprietary test lamp or voltmeter with insulated probes and fused leads) is working, i.e. indicating voltage.
Question 10.7
The nominal single phase voltage in the UK is ?
A: 230 volts
B: 240 volts
C: 415 volts
D: 400 volts
Answer: A This is nominal voltage for public electricity supply systems within Europe.

Question 10.8
When is live working permissible?
A: When the person carrying out the work is a competent person
B: When it is unreasonable in all circumstances for the equipment to be made dead and
suitable precautions are taken
C: When the means of isolation cannot be identified
D: When the person working on the equipment is wearing rubber gloves
Answer: B This is a requirement under r.14 of the EAW Regulations. However, it does not mean that live working is then ’safe’
Question 10.9
The FIRST step in the first aid procedure in the event of a person receiving an electric shock is:
A: take steps to remove the person from the live source
B: check airway, breathing and circulation
C: send for help
D: give the person mouth to mouth resuscitation
Answer: A Turn off the power if possible. Do not touch the person. Attempt to separate them from the source with a non-conducting object, such as a stick or broom.
Question 10.10
The specific effects on the human body of a major electric shock are one of the following:
A: dermatitis
B: burns and cardiac arrest
C: broken bones
D: chest pains
Answer: B
Question 10.11
The lowest level of electrical current which can harm the human body is normally measured in:
A: microamps
B: kiloamps
C: amps
D: milliamps
Answer: D Research has shown that a person is in serious danger of a fatal electric shock at, or above, approximately 30 milliamps.
Question 10.12
With regard to the effect of electrical current on the human body, one of the following is correct:
A: a 5 amp circuit breaker should prevent a person receiving a fatal electric shock
B: a 3 amp fuse should prevent a person receiving a fatal electric shock
C: a 30mA Residual Current Device (RCD) should prevent a person receiving a fatal electric shock.
D: a 5 amp rewireable fuse should prevent a person receiving a fatal electric shock
Answer: C An RCD is a mechanical switching device intended to cause the opening of the contacts when the residual current attains a given value under specified conditions.
Question 10.13
Where mains voltage is used to supply portable equipment, what additional protection is recommended?
A: Step-down transformer
B: Step-down generator
C: Cable avoidance tool
D: Residual current device
Answer: D A residual current device (RCD) does not guarantee safety and it is possible to suffer an electric shock or injury although it is operating correctly. Reduced low voltage systems (e.g. 110 volt centre point earthed) give more reliable protection against fatal electric shock.
Question 10.14
What colour cable USUALLY signifies 110 volt power supply on site ?
A: Black
B: Red
C: Blue
D: Yellow
Answer: D Yellow is the usual colour of cables, socket outlets, plugs, transformers etc which are used with a 110 volt supply.
Question 10.15
A portable electric generator on site has two power outlets, 110 volts and 230 volts. What colour would the 110 volt outlet be ?
A: Black
B: Yellow
C: Red
D: Blue
Answer: B Yellow is the usual colour of cables, socket outlets, plugs, transformers etc which are used with a 110 volt supply.
Question 10.16
What colour power outlet on a portable generator would supply 110 volts?
A: Black
B: Blue
C: Red
D: Yellow
Answer: D Yellow is the usual colour of cables, socket outlets, plugs, transformers etc which are used with a 110 volt supply.

 

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Re: Useful Information for Apprentices

Question 10.17
What action should you take if a workmate gets an electric shock ?
A: Phone the electricity board immediately
B: Dial 999 and ask for the fire brigade
C: Cut off the power and call for help
D: Try to pull them to safety
Answer: C If you can switch the power off, the electric hazard will be removed. First aid assistance will then probably be required. Do not touch someone who is still in contact with live electrical cables as you could also receive an electric shock.
Question 10.18
A residual current device is designed to operate in the event of one of the following:
A: overload
B: earth fault
C: lightning strike on the supply
D: short-circuit
Answer: B An RCD provides supplementary protection against direct contact of persons or livestock with live parts and reduces the risk of electric shock.
Question 10.19
Electrical installations on construction sites should be periodically inspected and tested:
A: every 3 months
B: every year
C: every 6 months
D: every month
Answer: A 3 monthly inspections of construction site installations are recommended in IEE Guidance Note 3.
Question 10.20
The maximum AC voltage which the human body can withstand without long term physiological effects in dry conditions is:
A: 110 volts
B: 230 volts
C: 50 volts
D: 400 volts
Answer: C Regarded as a non-fatal voltage level.
Question 10.21
Which of the following statements is true with regard to the dangers of electricity ?
A: Electricity is perfectly safe so long as you wear cotton gloves
B: Electricity is only dangerous if you are not wearing wellington boots
C: Electricity is only dangerous in wet weather
D: Electricity is dangerous at any time because you cannot tell by looking at a cable whether or not it is live
Answer: D The features which make electricity so dangerous are that you cannot see, hear or smell it. It can give you a very unpleasant surprise. Always assume that cables are live. ←←←
Question 10.22
What is the most serious effect that electric shock can have if you come into contact with a live part ?
A: The electric current can cause a slight tingling in the fingers
B: The electric current can cause burn marks on the fingers
C: The electric current can cause the heart to stop, resulting in death
D: The electric current can cause the finger muscles to twitch
Answer: C Contact with live electrical parts can be fatal. If you do not know otherwise, always assume that electrical parts are live.
Question 10.23
Your job involves you working near to hanging electrical cables which have bare ends. What should you do ?
A: Touch the cables to see if they are live
B: Carry on working, as there shouldn’t be a problem
C: Inform your supervisor and keep well away
D: Attempt to push the cables back into the ceiling void so that you can start work
Answer: C You must always assume that exposed cables are live until you know they are not. Contact with live electrical cables can kill.
Question 10.24
For all live working activities it is necessary to:
A: carry out a risk assessment
B: wear rubber gloves only
C: be accompanied
D: keep your fingers crossed
Answer: A
Question 10.25
An electrical Permit to Work is primarily a statement that:
A: someone else has taken responsibility for the work
B: the circuit or equipment is live
C: certain instructions need to be followed
D: the circuit or equipment has been isolated and is safe to work on
Answer: D Permits to work describe the procedures that prevent a major hazard, such as electricity or moving machinery, from causing harm, usually by isolation to effectively
ensure (in the case of electricity) ’dead’ working with no chance of it going ‘live’.
Question 10.26
Test instrument probes used for live testing on electrical systems should:
A: be manufactured in the UK
B: be accompanied by a calibration certificate
C: be fused
D: be coloured red
Answer: C To protect the instrument from damage by overcurrent while in use, test probes should have suitable high breaking capacity (hbc) fuses with a low current rating (usually not exceeding 500 mA), or a current-limiting resistor and fuse.

Question 10.27
Which of the following does the Electricity at Work (EAW) regulations apply to ?
A: All persons engaged for work purposes
B: Self employed persons only
C: Employees only
D: Employers only
Answer: A The EAW Regulations impose duties on employers employees and the self employed.
Question 10.28
The Electricity at Work Regulations require that:
A: persons working with electricity must have the appropriate level of knowledge and experience
B: a training course is necessary before anyone can work with electricity
C: only electricians can work with electricity
D: anyone supervised can work with electricity
Answer: A Competency is a requirement of r.16 of the EAW Regulations.
Question 10.29
The Electricity at Work Regulations apply to:
A: only low voltage systems
B: only extra-low voltage systems
C: all voltage systems
D: only high voltage systems
Answer: C The EAW Regulations cover the safe use of electricity in work activities, irrespective of voltage.
Question 10.30
Which of the following should not be used to prove a circuit or equipment is dead after isolation?
A: A two-pole voltage detector
B: A proprietary test lamp
C: A suitable voltmeter
D: A multimeter
Answer: D The use of multimeters, which can be incorrectly set, has often caused accidents and should not be used on electrical power systems.
Question 10.31
Which of the following is not a suitable means of isolating a circuit ?
A: Removing a fuse and locking the distribution board
B: Putting insulating tape over the circuit breaker
C: Padlocking the isolating switch
D: Fitting a padlocked circuit breaker lockout
Answer: B The isolating device should be switched off or the fuse removed. The switch, circuit breaker or enclosure should then be locked and the key removed. A notice or label should also be posted to warn that someone is working
on the circuit or apparatus.
Question 10.32
Which of the following work procedures on electrical systems will always require a permit-to-work to be issued ?
A: Dead working on low-voltage systems
B: Live working on low-voltage systems
C: Dead working on high-voltage systems
D: Live working on high-voltage systems
Answer: C An electrical permit-to-work should state what circuit or equipment has been made safe, how that has been achieved and what work is to be done. A permit should not, therefore, be used for live working. Such a permit is
always required for work on high-voltage systems, but can also be used for low-voltage systems.
Question 10.33
Optical fibre cable remnants should not be left lying around on site because:
A: They can be hot and burn upon contact
B: Laser beams still exist in the cut pieces
C: They can pierce the skin or eyes
D: They are toxic
Answer: C Fibre fragments can enter the bloodstream and cause infections in the skin or eyes. All fibre waste, particularly small pieces, should be placed in suitable receptacles.
Question 10.34
Why should the end of an optical fibre cable never be pointed towards your own or anyone else’s eyes ?
A: The beam can transfer a strong electric current
B: The colour of the beam is very hypnotic
C: The beam can bore a hole through the skin
D: The beam can damage the eyes
Answer: D Exposure to light sources such as lasers or highly concentrated visible or infrared light beams, associated with the testing or use of optical fibres, can cause damage to the eyes, or even blindness.

 

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Re: Useful Information for Apprentices

REPORTING ACCIDENTS
Question 3.1
What should you ensure if you suffer an injury through a manual handling operation?
A: You get paid for the job
B: The injury is recorded
C: You get help and carry on working
D: You take time off work
Answer: B All injuries must be recorded in the Company accident book
Question 3.2
Why should a serious accident be reported?
A: It helps the site find out what caused it
B: It is a legal requirement
C: So that the site manager can see who is to blame
D: So that the company will be held responsible
Answer: B Serious accidents (major injuries or those resulting in an absence of over 3 days) must be reported to the enforcing authority under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR)
Question 3.3
What immediate action should you take if you suffer an injury through carrying a load?
A: Advise your doctor of your injury
B: Tell your supervisor or employer
C: Tell your working companion
D: Carry on working as best you can
Answer: B All injuries must be recorded in the Company accident book
Question 3.4
Under RIDDOR, which one of the following must be reported?
A: Accidents where the injured person wishes to make a claim
B: Fracture other than to fingers, thumbs or toes
C: All ‘near misses’ even if no one was hurt
D: All accidents causing any injury
Answer: B This is classified as a ‘reportable major injury’ and must be reported to the enforcing authority under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR)
Question 3.5
Which one of the following have the power to examine an accident record?
A: The HSE inspector
B: An insurance company
C: A doctor
D: A workmate
Answer: A HSE inspectors have a range of powers, including this one.
Question 3.6
Which of the following should be recorded following an accident?
A: The date and time the accident occurred
B: Your date of birth
C: The weather conditions
D: Your National Insurance Number
Answer: A The information to be entered in an accident book (BI 510) includes when and where the accident happened, the name, address and occupation of the person who had the accident and details of how the accident happened and the injuries suffered. The weather conditions would only be included if they contributed to the accident
Question 3.7
Which one of the following accounts for most accidents each year on construction sites?
A: Struck by moving vehicles
B: Electrocution
C: Trench collapses
D: Slips, trips and falls
Answer: D HSE statistics show clearly that there are more slips, trips and falls than any other type of accident on site.
Question 3.8
Which one of the following is NOT classified as a major injury under RIDDOR?
A: A fractured finger
B: Fractured arm
C: Temporary loss of eyesight
D: Broken wrist
Answer: A RIDDOR excludes fractures to fingers, thumbs or toes from the definition of ‘reportable major injuries’
Question 3.9
Which one of the following should you do if you witness a serious accident on site?
A: Pretend you saw nothing
B: Say nothing in case you get in trouble
C: Discuss what to do with your workmates
D: Tell your supervisor what you saw happening
Answer: D If the supervisor is aware of an accident he can take steps to prevent a recurrence. The employer also has
legal duties to report certain incidents to the enforcing authority.
Question 3.10
A workmate tells you that he witnessed an accident the previous day and the victim was taken to hospital. He
asks you for advice on what he should do. Do you tell him to:
A: speak to the site nurse about what he saw
B: tell his supervisor that he saw what happened
C: telephone the hospital to find out how the injured person is
D: say nothing to anyone in case he gets someone in trouble
Answer: B If the supervisor is aware of an accident he can take steps to prevent a recurrence. The employer also has
legal duties to report certain incidents to the enforcing authority.

Question 3.11
If a person at work suffers an injury (other than a major injury) due to an accident at work, it is reportable under
RIDDOR if they are incapacitated for work for:
A: Over 1 day
B: Over 3 days
C: Over half a day
D: Over 2 days
Answer: B An over-three-day injury is one which is not major but results in the injured person being away from work or
unable to do the full range of their normal duties for more than three days (including any days they wouldn’t
normally be expected to work such as weekends, rest days or holidays) not counting the day of the injury itself.
Question 3.12
What must an employer do with their accident records following completion of a construction project?
A: They are sent to the Health and Safety Executive
B: They are destroyed on site with other non-essential documents
C: They are kept safe by the employer
D: They are sent to the employer’s insurance company
Answer: C Accident records must be kept by an employer for at least three years.
Question 3.13
At work who would you report a dangerous occurrence to?
A: The emergency services
B: Your supervisor or employer
C: Another employee
D: The client for the project
Answer: B Under RIDDOR, an employer has a legal duty to report certain work-related accidents, but to do this they will need to know that an accident has occurred.
Question 3.14
Following a reportable dangerous occurrence when must the enforcing authority be informed?
A: Within 5 days
B: Within 48 hours
C: Without delay
D: Within 24 hours
Answer: C The enforcing authority must be notified forthwith by the quickest practicable means and a report must also be sent to them within 10 days.
Question 3.15
Accidents causing any injury should always be recorded in:
A: The site engineer’s day book
B: Your employer’s accident recording system
C: Your personal diary
D: The main contractor’s diary
Answer: B All accidents should be recorded in the accident book
Question 3.16
Which one of the following is classed as an occupational disease under RIDDOR?
A: Mental disorder
B: Asbestosis
C: Amputation
D: Influenza
Answer: B Asbestosis is a reportable disease under RIDDOR.
Question 3.17
When a person is injured at work, who should enter the details in the accident book?
A: The injured person’s supervisor
B: The injured person or anyone acting for them
C: The site manager or engineer
D: The site safety manager
Answer: B This is the procedure for recording accidents internally in the accident book
Question 3.18
If you are involved in a minor accident at work, whose duty is it to report it to site management?
A: Any witness to the accident
B: The police, fire or ambulance who attend
C: It is your own responsibility
D: The site foreman should report it
Answer: C Employers rely on employees to advise them of occurrences at work.
Question 3.19
You have suffered an accident which has made you incapable of your normal work for over 3 days
Which of the following actions MUST be taken by your. employer?
A: The emergency services are asked to attend the site
B: The local hospital is informed
C: The relevant enforcing authority is informed
D: A deduction is made from your wages for days lost
Answer: C An over-three-day injury is one which is not major but results in the injured person being away from work or
unable to do the full range of their normal duties for more than three days (including any days they wouldn’t normally be expected to work such as weekends, rest days or holidays) not counting the day of the injury itself.
Question 3.20
The collapse of scaffolding is only notifiable as a dangerous occurrence when the scaffolding is which one of the following?
A: Over 15 metres in height
B: Any height
C: Over 10 metres in height
D: Over 5 metres in height
Answer: D This is one of the requirements of RIDDOR.

 

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Re: Useful Information for Apprentices

Question 3.21
If there is a fatal accident on site, when must the Health and Safety Executive be informed?
A: Without delay
B: Within 10 days
C: Within 7 days
D: Within 5 days
Answer: A The enforcing authority must be notified without delay by the quickest practicable means and a report must also be sent to them within 10 days.
Question 3.22
When must an accident be recorded in the site’s accident book?
A: When an accident causes damage to plant or equipment
B: Only when a person is injured and will be off work for more than three days
C: When the injury is serious enough for first aid to be needed.
D: When an accident causes injury to an employee while at work
Answer: D An accident causing an injury to an employee at work should be recorded in the accident book
Question 3.23
Which of the following have to be entered into the accident book?
A: All accidents causing any damage
B: All accidents causing an injury
C: Only accidents causing serious injury
D: Only accidents causing time off work
Answer: B An accident causing an injury to an employee at work should be recorded in the accident book
Question 3.24
When must injury accidents be recorded?
A: Only if you break a bone
B: Only if you have time off work
C: Any time they occur
D: Only if you need to go to hospital
Answer: C An accident causing an injury to an employee at work should be recorded in the accident book
Question 3.25
An entry must be made in the accident book when:
A: the person has been off sick for three days
B: management thinks it is appropriate
C: an accident causes personal injury to an employee
D: the severity of the accident may result in a compensation claim
Answer: C An accident causing an injury to an employee at work should be recorded in the accident book
Question 3.26
Which of the following MUST be recorded in an accident book?
A: Your National Insurance number
B: Your date of birth
C: Your occupation
D: Your phone number
Answer: C The information to be entered in an accident book includes when and where the accident happened
the name, address and occupation of the person who had the accident and details of how the accident happened
and the injuries suffered.
Question 3.27
Which of the following can you learn from an accident?
A: A combination of human error and mechanical failure always causes injury
B: Ideas on how you would prevent it happening again
C: That mechanical failures are most dangerous
D: How human error is always a cause
Answer: B An accident investigation should not only assess the cause, but also howsimilar accidents can be prevented in the future.
Question 3.28
Could making an entry in the accident book help you if you later make a claim for compensation?
A: Only if it is a serious injury
B: No
C: Only in the event of a fatality
D: Yes
Answer: D This is laid down in Social Security Legislation.
Question 3.29
Why is it important to report ’near miss’ accidents to your employer?
A: It’s the law
B: To make the figures look good
C: So lessons can be learned, preventing an accident next time
D: So that someone can be disciplined
Answer: C The HSE advises that ‘near misses’ should be investigated to prevent their recurrence.
Question 3.30
Who should you report serious accidents to?
A: Your workmate
B: Your employer or supervisor
C: The police
D: The ambulance service
Answer: B If the supervisor is aware of an accident he can take steps to prevent a recurrence. The employer also has
legal duties to report certain incidents to the enforcing authority.

Question 3.31
What is the aim of carrying out an accident investigation?
A: To determine the cause(s) and prevent a re-occurrence
B: To establish what injuries were sustained
C: To find out who is at fault
D: To establish the cost of any damage incurred
Answer: A An accident investigation should not only assess the cause, but also how similar accidents can be prevented in the future.
Question 3.32
You have witnessed a serious accident on your site, and are interviewed by an HSE inspector. Should you:
A: tell the inspector what your mates say you should tell him
B: ask your supervisor what you should say to the inspector
C: co-operate fully with the inspector and tell him exactly what you saw
D: don’t tell him anything
Answer: C This is good practice, but it can also be an offence to withhold important information from an inspector.

Personal Protective Equipment at Work
Question 4.1
When working in dusty conditions, what of the following would give the LEAST level of protection?
A: Compressed airline breathing helmet
B: Positive pressure powered respirator
C: Self contained breathing apparatus
D: Half mask dust respirator
Answer: D Protection factors are given in HSE publication HSG53‘Respiratory protective equipment at work – A practical guide’
Question 4.2
In hot weather which one of the following is correct with regard to safety helmets?
A: You can take off your helmet while working inside the building
B: You must continue to wear your helmet
C: You can drill holes in your safety hat for ventilation
D: You do not need to wear your helmet
Answer: B The Construction (Head Protection) Regulations 1989 require suitable head protection to be worn unless there is no foreseeable risk of head injuries other than by the wearer falling, or when directed to do so by their employer or the person who controls their activities on site.
Question 4.3
Which one of the following should you do if your personal protective equipment (PPE) is damaged?
A: Obtain new equipment when available
B: Report to your Supervisor without delay
C: Reduce the amount of time you use it
D: Carry on working
Answer: B Employees are required to report any defective PPE to their employer (PPE at Work Regulations 1992, Regulation 7)
Question 4.4
If personal protective equipment (PPE) is defective, what should you do?
A: Complain to the Health and Safety Inspector
B: Get your work mate to mend it if possible
C: Report it to your supervisor
D: Repair if possible and continue to use it
Answer: C Employees are required to report any defective PPE to their employer (PPE at Work Regulations 1992, Regulation 7)
Question 4.5
In normal use, what item of PPE is NOT essential for the operator of a cartridge-operated tool ?
A: Safety eyewear
B: Hearing protection
C: Wellington boots
D: Safety helmet
Answer: C Wellingtons do not offer protection against the risks associated with the use of a cartridge-operated tool.
Question 4.6
Can you opt out of wearing personal protective equipment (PPE)?
A: Yes, by informing the site supervisor
B: Yes, by writing officially to your employer
C: No, you cannot opt out
D: Yes, if it is uncomfortable
Answer: C You cannot legally “opt out” of being protected from significant risks at work. This includes wearing the necessary PPE.
Question 4.7
What is the most important item of personal protective equipment (PPE) when working on or near a highway?
A: Safety footwear
B: Waterproof clothing
C: Hard hat
D: High visibility vest
Answer: D The other PPE may also be required.
Question 4.8
If you are drilling into concrete with a masonry drill, in which one of the following circumstances will you need to wear eye protection?
A: Always
B: Only when drilling overhead
C: Only if the drill is bigger than 10mm
D: Not if drilling into the floor
Answer: A Suitable eye protection must always be worn when working with power-driven tools where chippings are likely to fly or abrasive materials could be propelled.
Question 4.9
When must you wear all personal protective equipment (PPE) provided by your employer?
A: As instructed by your employer
B: Only if it fits
C: When you want to
D: Only when you need to
Answer: A Under the PPE at Work Regulations 1992, employees must wear PPE as instructed.
Question 4.10
When MUST an employer provide personal protective equipment (PPE)?
A: To protect against a risk of harm that cannot be controlled another way
B: Twice a year
C: If the client or main contractor specifies it in the contract
D: Every 5 years
Answer: A When using a cartridge-operated tool, such as a nail gun, shatter proof goggles should be worn.

 

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Re: Useful Information for Apprentices

Question 4.12
Which of the following must your safety helmet comply with to meet with the requirements of the Construction (Head Protection) Regulations?
A: Be suitable for you
B: Be a good visible colour
C: Be stamped with the maker’s name
D: Be less than 1 year old
Answer: A An assessment of the suitability of head protection would include consideration of whether it can be adjusted to suit the individual who is to wear it, that it is compatible with the work to be done and that is comfortable to wear.
Question 4.13
In which of the following ways should you wear your safety helmet?
A: With the peak raised to deflect falling material
B: With the helmet back to front
C: With the peak raised to give good vision
D: Square on your head, properly adjusted
Answer: D Employees are required to wear head protection properly under the Construction (Head Protection) Regulations 1989.
Question 4.14
When an employee has been issued with eye protection, what are their duties under the Personal
Protective Equipment at Work Regulations?
A: To ensure that they are the right type of protector
B: Not to loan the equipment to other operatives
C: To use the protection in accordance with training and instruction
D: To pay for replacement of lost eye protection
Answer: C Regulation 10(2) requires that every employee shall use any PPE in accordance with the training and instruction received.
Question 4.15
When should you wear safety footwear on site?
A: Only when working on scaffolds
B: When there is a risk of a foot injury
C: Only when working outdoors
D: Only if the site conditions are wet
Answer: B Suitable safety footwear should be worn if there is a risk of injury from objects falling onto the foot or sharp objects such as nails, penetrating the sole.
Question 4.16
With regard to the use of personal protective equipment (PPE), which one of the following statements is true?
A: If you do not use the personal protective equipment (PPE) provided you will probably not come to any harm
B: Personal protective equipment (PPE) protects only the user from the dangers present
C: Personal protective equipment (PPE) need only be provided if it is not too expensive
D: Personal protective equipment (PPE) need only be used if it is available
Answer: B PPE is there to protect the individual. Wearing PPE does not protect other people nearby.
Question 4.17
Which of the following statements is TRUE when an employer issues personal protective equipment (PPE)?
A: The employer can charge you for the full cost of it
B: The employer cannot charge you for it
C: The employer can charge you for up to half the cost of it
D: The employer can only charge you for it if you lose or damage it
Answer: B Employers cannot charge for PPE such as hard hats, gloves, required by law (and the bulk of PPE is required by law).
Question 4.18
Which one of the following must apply to any hard hat provided ?
A: It is CE - marked
B: It is less than 5 years old
C: It is less than 1 year old
D: It is less than 2 years old
Answer: A All PPE should be CE – marked, indicating that it meets the basic health and safety requirements
Question 4.19
When using personal protective equipment (PPE) legally you must do which of the following?
A: Not interfere with it or misuse it
B: Replace it at your own expense if it is damaged
C: Return it to the manufacturer when damaged
D: Clean it properly once a week
Answer: A Interfering with or misusing items provided in the interests of health, safety or welfare is an offence under the HSW Act 1974 (section 8)
Question 4.20
If it is necessary for an employee to use personal protective equipment, who has a duty to provide it?
A: The trade union
B: The employee
C: The employer
D: The principal contractor
Answer: C This is a requirement of the PPE at Work Regulations 1992 (Regulation 4 ).
Question 4.21
When should a safety helmet be worn on site?
A: At all times unless there is no foreseeable risk of injury to the head other than by falling.
B: When you are out in the open air
C: When walking to and from a place of work
D: Only when something may fall
Answer: A The circumstances when there is no foreseeable risk of head injury from falling or swinging objects or striking the head against something will be very limited in most construction work.

Question 4.22
A colleague has drilled holes in the top of his safety helmet because the weather is hot. Is this:
A: acceptable if the holes are small
B: his choice
C: acceptable
D: in breach of legal requirements
Answer: D Interfering with or misusing items provided in the interests of health, safety or welfare is an offence under the HSW Act 1974 (section 8).
Question 4.23
Who has a duty to provide PPE (Personal Protective Equipment) for use by an employee?
A: the employer
B: the principal contractor
C: the employee
D: the client
Answer: A This is a requirement of the PPE at Work Regulations 1992 (Regulation 4 ).
Question 4.24
When would it be appropriate to wear a bump-cap instead of a safety helmet?
A: When there is no foreseeable risk of injury from falling or swinging objects
B: In warm weather
C: When working in excavations
D: When working on a ladder
Answer: A Industrial scalp protectors (bump caps) can protect against striking fixed obstacles, scalping or entanglements. They do not provide suitable protection against falling or swinging objects.
Question 4.25
How can you protect your eyesight while working on site?
A: By squinting
B: By not looking directly at what you are doing
C: By wearing the correct type of eye protection
D: By wearing sunglasses
Answer: C
Question 4.26
When should head protection be worn on a construction site?
A: At all times except by those who are self employed
B: Only when you feel like it
C: At all times unless you are working on scaffold
D: At all times unless there is no foreseeable risk of injury to the head other than by falling
Answer: D This is a requirement of the Construction (Head Protection) Regulations
Question 4.27
Why should a high visibility vest be worn when working on roads?
A: So road users and plant operators can see you
B: Because you were told to do so
C: Because it will keep you warm
D: So that your mates can see you
Answer: A Many workers are struck and injured, often seriously, by moving vehicles.
Question 4.28
When considering what measures to take to protect people’s health and safety, PPE should always be regarded as:
A: the last resort
B: the first line of defence
C: the best way to tackle the job
D: the only practical measure
Answer: A Engineering controls and safe systems of work should always be considered first.

 

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Re: Useful Information for Apprentices

Health and Hygiene
Question 5.1
Exposure to asbestos fibres may cause which one of the following ?
A: Dermatitis
B: Asthma
C: Glandular fever
D: Asbestosis
Answer: D Breathing in asbestos fibres can also lead to a number of other diseases, including lung cancer and mesothelioma :
Question 5.2
Asbestos is suspected in the workplace, during renovation do you :
A: Remove it
B: Paint it
C: Ignore it
D: Seek guidance immediately
Answer: D Competent advice must be sought, to prevent exposure to the worker or others, either at the time, or subsequently :
Question 5.3
Which of the following statements about asbestos is TRUE ?
A: Asbestos is not really a hazard to health
B: White asbestos is safe to use
C: All asbestos can be a hazard to health
D: Only brown and blue asbestos are a hazard to health
Answer: C While blue and brown asbestos are most hazardous, white asbestos can also cause fatal diseases.
Question 5.4
While working you discover material you think could be asbestos. What should you do?
A: Clear any dust and fragments, put them in a bin then carry on working
B: Inform the site nurse
C: Stop working immediately and report your suspicions to your supervisor
D: Dampen the material to prevent further dust being created, then carry on working
Answer: C It is essential to stop work if asbestos is found or suspected, and await competent advice on what to do next.
Question 5.5
Can you tell by the smell of a product whether it is likely to cause harm ?
A: No
B: Only within an enclosed space
C: Yes
D: Only if you have been trained
Answer: A Many harmful substances have no smell
Question 5.6
How would you recognise a hazardous substance?
A: By a symbol on the container
B: By its smell
C: The colour of the label on the container
D: It will be in a suitable container
Answer: A The Chemicals (Hazard Information and Packaging for Supply) Regulations (CHIP) requires suppliers to provide information on the hazards of the chemicals they supply
Question 5.7
Which of the following does NOT cause skin problems?
A: Bitumens
B: Solvents
C: Asbestos
D: Epoxy resins
Answer: C Asbestos is potentially very harmful if inhaled, but does not affect the skin significantly.
Question 5.8
When an assessment has been carried out under COSHH Regulations, the risks and control measures
should be explained to:
A: the operatives using the substance
B: all employees on site
C: the accounts department
D: the person in charge of the stores
Answer: A All those working with the hazardous substances in question need to know about any risks.
Question 5.9
If your hands are very dirty, what should you use to get them clean ?
A: White Spirit
B: Paraffin
C: Soap and water
D: Thinners
Answer: C The other substances can remove natural oils from the skin.
Question 5.10
The presence of rats on site creates a risk of catching Weil’s disease. What is the EASIEST PRACTICAL
MEASURE that you can take to discourage the presence of rats ?
A: Avoid leaving scraps of food lying about
B: Lay traps containing rat poison
C: Contact the local Environmental Health Officer
D: Bring a large cat on site
Answer: A The easiest solution is to avoid leaving food around, since this is what attracts vermin.
Question 5.11
Why is personal hygiene so important?
A: So you don’t smell
B: Because the COSHH regulations require it
C: To protect your own and others’ health
D: To stop you catching something nasty
Answer: C

Question 5.12
If you have been handling lead, how is it most likely toget into your blood stream?
A: By not wearing safety goggles
B: By not reporting the matter to the HSE
C: By not using the correct safety footwear
D: By not washing your hands before eating
Answer: D The route into the body is ingestion, normally from lead contamination on the hands.
Question 5.13
The number of toilets provided on site depends on:
A: The type of work being completed
B: The ratio of male and female workers on site
C: The duration of the work on site
D: The number of personnel on site
Answer: D Guidance on the provision of welfare facilities is given in HSE publication ‘Health and Safety in Construction‘.
Question 5.14
Which of the following is not required to be provided under the Construction regulations?
A: Toilet Facilities
B: Washing Facilities
C: Hot Food
D: Drinking Water
Answer: C Guidance on the provision of welfare facilities is given in HSE publication ‘Health and Safety in Construction‘.
Question 5.15
The extended use of powered hand-held tools and equipment may lead to which medical condition?
A: Vibration white finger
B: Weil’s disease
C: Asbestosis
D: Dermatitis
Answer: A Hand-arm vibration can cause a range of conditions(including vibration white finger) collectively known as
hand-arm vibration syndrome, as well as diseases such as carpal tunnel syndrome .
Question 5.16
What must your employer do if the daily personal noise exposure is at or exceeds 85 dB(A)?
A: Provide hearing protection to those employees who ask for it
B: Issue hearing protection to those exposed and ensure that it is worn
C: Tell employees to buy their own hearing protection
D: Report it to the Health and Safety Executive
Answer: B This is an interim measure under the Control of Noise at Work Regulations 2005 when the daily personal noise exposure is at or exceeds the upper exposure action value of 85 dB(A). Exposure should subsequently be reduced by implementing organizational or technical measures.
Question 5.17
What are the lower and upper action values with regard to daily personal noise exposure, as defined in the Control of Noise at Work Regulations 2005?
A: 85 dB(A) and 90 dB(A)
B: 80 dB(A) and 85 dB(A)
C: 70 dB(A) and 80 dB(A)
D: 75 dB(A) and 85 dB(A)
Answer: B Daily personal noise exposure is the average noise level experienced by an individual over an 8 hour period.
Question 5.18
At or above what level of daily personal noise exposure does an employer have to provide hearing protection if it is requested by an employee?
A: 90 dB(A)
B: 95 dB(A)
C: 80 dB(A)
D: 85 dB(A)
Answer: C This is one of the duties of employers under the Control of Noise at Work Regulations 2005 when the lower exposure action value of 80 dB(A) is reached or exceeded.
Question 5.19
The effects of damage to your hearing by long-term exposure to high noise levels:
A: can be corrected by an operation
B: are permanent
C: will be reduced when you change jobs
D: can be reversed to near normal, with time
Answer: B Hearing damage due to long-term noise exposure is irreversible.
Question 5.20
Hearing protection should be worn:
A: in designated areas
B: in noisy internal areas only
C: at any workplace
D: only on building sites
Answer: A Employees must wear hearing protectors when exposed at or above the upper exposure action values and within hearing protection zones.
Question 5.21
Wearing suitable hearing protection:
A: stops you hearing distracting conversations
B: stops you hearing all noise
C: brings noise down to an acceptable level
D: repairs damaged hearing
Answer: C Hearing protection still allows some noise to reach the ear, but, if it has been correctly chosen, will reduce noise levels to an acceptable level.
Question 5.22
Which of the following is one of the recommended means of protecting your hearing?
A: Rolled tissue paper
B: Cotton wool pads
C: Soft cloth pads
D: Ear defenders
Answer: D The others are not considered to be suitable types of hearing protection.

Question 5.23
Which of the following would not reduce the risks from hand-arm vibration when using a hammer-action tool?
A: Selecting the lowest vibration tool that is suitable and which can do the work efficiently
B: Wearing gloves to keep the hands warm
C Working as a team to share the work out
D: Making sure one person does all the work with the tool
Answer: D Where tools require constant or frequent use, rotas will avoid individuals having long exposure to vibration.
Question 5.24
Which of the following animals can carry Weil’s disease?
A: Snake
B: Sheep
C: Rat
D: Pig
Answer: C Weil’s disease is a serious and sometimes fatal infection that can be transmitted to humans by contact with infected rats. Another form of Leptospirosis infection can be transmitted from cattle to humans.
Question 5.25
You are most likely to catch Weil’s disease (Leptospirosis) if you:
A: Work near wet ground, waterways or sewers
B: Work near air conditioning units
C: Fix showers or baths
D: Drink water from a standpipe
Answer: A Anyone who is exposed to rat urine is at risk, particularly sewer workers and farmers. Those in contact with canal or river water are also at risk.
Question 5.26
What should you do if the toilets on your site are continually dirty?
A: Ignore the problem – its normal on a construction site
B: Make sure you tell someone who can sort it out
C: Find some cleaning materials and clean it up yourself
D: Ask in a nearby café or pub if you can use their toilets
Answer: B How often welfare facilities on site require cleaning will depend on the number of people on site and how quickly they get dirty. The person in control of the site should make sure someone is responsible for keeping the facilities clean and tidy.
Question 5.27
Excessive sunlight on bare skin can cause which serious health problem?
A: Dermatitis
B: Rickets
C: Acne
D: Skin cancer
Answer: D Ultraviolet rays in sunlight can cause sunburn and premature ageing of the skin. The most serious effect, however, is an increased chance of developing skin cancer.

 

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“ First Aid After Electric Shock “
Currents of the order of 15 mA at mains frequency passing through the body cause muscular contractions that make it difficult for a person to let go. Currents around 100 mA cause irregular contractions of the heart which are likely to prove fatal :
Do not touch the casualty until the current is switched off. If the current cannot be switched off, stand on some dry insulating material and use a wooden or plastic implement to free the casualty from the electrical source. If breathing has stopped, start mouth-to-mouth respiration and continue until the casualty starts to breathe or until medical help arrives.
“ Mouth-to-Mouth Respiration “
• Lie the casualty flat if possible.
• Ensure no obstructions are present in the mouth ( remove dentures, etc.).
• Ease constriction at the neck, chest and waist.
• Place a rolled jacket or pad under the shoulders to arch the neck.
• Pinch the casualty’s nostrils and draw the chin forward to open the mouth.
• Take a moderately deep breath and breathe steadily into the casualty’s mouth (chest will rise).
• Lift your own head and allow the casualty to exhale (see chest deflate).
• Repeat this cycle at a rate of 6 to 8 per minute.
• Continue until the casualty resumes breathing unaided or until qualified medical services take over, however long this takes.
• If breathing resumes, place casualty in the Open Airway (Recovery) Position and treat as an unconscious casualty.
• Check the casualty for secondary injuries caused by falling or being thrown by the shock.
Emergency Resuscitation : wherever there is a foreseeable risk of an accident resulting in an unconscious casualty due to electric shock.
“ Open Airway (Recovery) Position “ Open Airway (Recovery) Position :
Electrical burns even from minor shocks which may leave only superficial signs of damage, are often deep-seated in the tissue below the skin. Electrical burns should always be examined by a doctor.

 

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HSE information sheet :

Carrying out a risk assessment
To help you identify the precautions that are necessary to carry out electrical testing work safely, you need to do an assessment of the risk of injury posed by the work being done. When assessing the risk, you need to think about the hazards that are present; who may be harmed and how; and the effectiveness of existing precautions. Bear in mind the examples of factors given in this
guidance which might increase the risk of injury.
When carrying out a risk assessment for electrical testing, ask yourself the following questions:
(a) Can the work be done with the equipment dead ?
(b) Is it absolutely necessary for someone to be working on or near equipment that is live at
dangerous voltages or current levels ?
(c) Have suitable precautions been taken to avoid danger and, where necessary, prevent injury ?
(d) Is the person doing the work competent for that type of work, or if not, adequately supervised ?

* The person carrying out the testing should have received adequate training and, if appropriate, be
competent to make an on-site risk assessment. This should take account of the ability of those employed by the customer to heed any warnings that might be given, be given,
in order to prevent unauthorised people from approaching the unit under test.

* Test equipment, leads and cables should be handled carefully to avoid injury. The following precautions are recommended:
(a) All leads and cables which can be energised at dangerous voltages should be robustly insulated
and properly terminated. All connections of conductors which can be energised at dangerous
voltage, should be electrically and mechanically robust to prevent conductors becoming
accidentally exposed. There should be no exposed conductors at dangerous voltages at any purpose built
connectors or jigs into which the product is fixed for testing;
(b) Test equipment connecting leads, probes and connectors should be sufficiently protected to
prevent accidental contact when being applied to and removed from live parts;
(c) Where practicable, place the equipment under test into interlocked enclosures. This allows
connections to be made while the equipment is isolated;
(d) Where practicable, apply test leads while the equipment is isolated and then energise it. To
make sure that the equipment is isolated, a suitable isolating device should be used which must be:
(i) appropriate and convenient for the intended use;
(ii) suitably located;
(iii) readily identifiable (eg by durable marking) as to which circuits or part of the test area is served;
(iv) provided with adequate means to prevent the supply isolator being switched on (either inadvertently, mistakenly, or by an unauthorised person).
What are the legal requirements?
The Electricity at Work Regulations 1989 are the principal legislation relating to electrical testing activities
and regulation 14 is particularly relevant to live testing activities. In addition, employers are required under
regulation 3 of the Management of Health and Safety at Work Regulations 1999 to assess the risks to the health and safety of their employees while they are at work, in order to identify and implement the necessary precautions to ensure safety.

(e) Where practicable, the power supplies to the unit under test and to the mains-powered
instrumentation should include a residual current device (RCD) used as supplementary protection.
For personal protection it is recommended that the rated tripping current of the RCD should be no
more than 30mA (milliamps).

Precautions :
Where possible, the work should be done with the equipment dead (this is a requirement of the Electricity
at Work Regulations 19892). Otherwise, adequate precautions, which should be identified in your risk
assessment, must be taken to ensure safety. NB:

 

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Health & Safety Policy Document :
What is a health and safety policy statement ?
Your health and safety policy statement sets out how you manage health and safety in your
organisation. It is a unique document that shows who does what; and when and how they do it.
This is an example of a policy statement that H o w e v e r, you do not have to use this document
or format. You are free to re c o rd and store the i n f o rmation in any form you choose. This form a t
gives you an idea of the kind of information you need to re c o rd .
Why do I need a health and safety policy statement ?
The health and safety policy statement is your starting point to managing health and safety in
the workplace. By law, (Health and Safety at Work etc Act 1974 section 2(3)) if you employ
five or more people you must have a written health and safety policy. This contains your
statement of general policy on health and safety at work and the organisation and arrangements for putting that policy into practice.
Writing a health and safety policy statement is m o re than just a legal re q u i rement – it is your
commitment to planning and managing health and safety. It is the key to achieving acceptable
s t a n d a rds, reducing accidents and cases of work related ill health and it shows your employees
that you care for their health and safety.
Who should do what ?
With very few exceptions, the responsibility for health and safety rests on you as an employer.
However, many day-to-day tasks may be delegated. Your statement should show clearly how these tasks are allocated, but remember,
you will still have ultimate responsibility. You should consult your employees (through safety representatives, if you have any) about
the policy statement. Everyone should be able to see from the policy statement exactly who is responsible for different things, such as advice,
reporting an accident, and first aid.
When and how should they do it ?
Your policy statement should describe your arrangements, i.e. the systems and procedures
you have in place for ensuring employees’ health and safety. You may wish to refer to other documents,
eg works’ rules, safety checklists, training programmes, emergency instructions, etc. All employees may not need to see all the
other documents, but they must see the policy statement itself.
How often do I need to revise the policy statement ?
It should be reviewed and possibly revised in the light of experience, or because of operational or
organisational changes. It is useful to review the policy regularly (e.g. annually).
Do I have to do anything else ?
Yes, you have other legal duties under other legislation. In particular, under the Management
of Health and Safety at Work Regulations 1999, you have to assess the risks arising from your work activities and record the significant findings
You also have to record your arrangements for health and safety (you can use this document to do that). Depending on your type of work, there may be other specific legislation that will apply. REMEMBER: What you write in the policy
has to be put into practice. The true test of a health and safety policy is the actual conditions in the workplace, not how well
the statement is written.
How to use this guidance :
This guidance is split into three parts. It contains a statement of general policy based on your legal duties under the Health and Safety at Work etc
Act 1974. Then you can re c o rd your org a n i s a t i o n a l responsibilities and your arrangements to ensure
the health and safety of your employees.

Health and Safety at Work etc Act 1974 :

This is the Health and Safety Policy Statement of
Our statement of general policy is:
* to provide adequate control of the health and safety risks arising from our work activities;
* to consult with our employees on matters affecting their health and safety;
* to provide and maintain safe plant and equipment;
* to ensure safe handling and use of substances;
* to provide information, instruction and supervision for employees;
* to ensure all employees are competent to do their tasks, and to give them adequate training;
* to prevent accidents and cases of work-related ill health;
* to maintain safe and healthy working conditions; and
* to review and revise this policy as necessary at regular intervals.
Signed (Employer) : Date Review : date

Responsibilities :

1 Overall and final responsibility for health and safety is that of
Note 1 : Your name must be insert e d h e re. As the employer (i.e. sole t r a d e r, senior partner or managing director) you have overall responsibility for health and safety
2 Day-to-day responsibility for ensuring this policy is put into practice is delegated to
Note 2 : If you are not always there, or do not have time to manage on
a day-to-day basis, you can delegate this role to someone else, e.g. dire c t o r, manager or
supervisor. You will need to e n s u re that they keep you fully informed of health and safety
matters – it will still be your overall responsibility y.
3 To ensure health and safety standards are maintained/ i m p roved, the following people have responsibility in
the following are as
Note 3 : You may delegate functions to people within your org a n i s a t i o n ,
either by specific areas within the workplace or by topic. You should include their specific
responsibilities in their job responsibilities in their job description (if they have one). You must also ensure that they
a re competent to undertake their health and safety responsibilities and have adequate resources to enable
them to do their job properly. It is important that responsibilities are clearly set out – this will make sure that if
t h e re are any health and safety concerns, they can be reported to the right person, so they can be dealt with.
You may wish to insert a diagram or chart showing your management structure / arrangements .
Name Responsibility
4 All employees have to: l co-operate with supervisors and managers on

* co-operate with supervisors and managers on
health and safety matters;
*not interfere with anything provided to safeguard
their health and safety;
* take reasonable care of their own health and safety; and
* report all health and safety concerns to an appropriate person (as detailed in this policy statement).
Note 4 : Employees have legal responsibilities to take care of
the health and safety of themselves and others, and to co-operate with you to help you comply with the law.
E q u a l l y, if employees have any concerns over health and safety issues, they should be
clear about whom they should tell, so that the concerns can be addressed .

 

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The new Health and Safety (Offences) Act 2008
January 2009 saw one of the most significant changes to UK law for electrical duty holders coming into force, placing them firmly in the firing line in the event of health and safety breaches. The implications of the Health and Safety (Offences) Act 2008 are severe for those in the industry, below we examine how you can reduce risk for yourself at a time when many companies are searching for ways to trim budgets.
What is it?
New legislation came into force on 16th January 2009 that has increased the penalties and provided courts with greater sentencing powers for individuals and dutyholders (that is, employees & employers) who breach health and safety laws. More specifically in the case of electrical legislation, non compliance with 'The Electricity at Work Regulations 1989'. The Act amends Section 33 of the Health and Safety at Work etc Act 1974, and raises the maximum penalties available to the courts in respect of certain health and safety offences.
The maximum Magistrates' court fine for most safety breaches has risen from £5,000 to £20,000. It is now also possible to jail offenders for up to 12 months for more offences than ever before.
Why has it been introduced?
It is generally accepted that the level of punishment for some health and safety offences does not fit the crime. These changes will ensure that sentences can now be more easily set at a level to deter businesses that do not take their health and safety management responsibilities seriously and further encourage employers and employees to comply with the law. HSE enforcement policy is to:
"target those who cut corners, gain commercial advantage over competitors by failing to comply with health and safety law and who put workers and the public at risk.
Around 1,000 electrical accidents are reported to the HSE every year.
The Act aims to free-up the legal system by giving Magistrates the power to appropriately handle the more serious health and safety breaches. Previously it would have been costly to take these cases to the Crown Court and in many instances the plaintiff would settle with the minimal Magistrates fines.
The reduction in costs for plaintiffs in a Magistrates Court may mean that we witness a rise in the number of prosecutions so firms should be extra vigilant when it comes to their health and safety policies.
Will it affect me as an individual?
If, even as an employee, you are responsible for electrical safety and breach the law by not providing a safe working electrical environment, then in the eyes of the law you are most certainly culpable and therefore exposed to the penalties listed below.
How easy will it be to implement?
More cases will be resolved in the lower courts and justice will be faster, less costly and more efficient. Jail sentences for particularly blameworthy health and safety offences committed by individuals, can now be imposed reflecting the severity of such crimes, whereas there were more limited options in the past.
What are the penalties?
• The maximum fine which may be imposed in the lower courts is £20,000 for most health and safety offences. There are unlimited fines in the higher courts.
• Imprisonment is an option for individuals prosecuted for health and safety offences in both the lower and higher courts - up to 12 months in a Magistrates Court and 2 years in a Crown Court.
• Certain offences, which are currently triable only in the lower courts, will be triable in either the lower or higher courts.
What action can I take in order to defend myself?
Compliance with Health & Safety Laws, i.e. The Electricity at Work Regulations 1989, will go a long away to ensure you do not commit an offence under the new Act. More specifically:
• Documented evidence of a well maintained electrical system, i.e. inspect & Test Records, Electrical Drawings.
• Competent workforce. That is, appropriately experienced and trained personnel kept abreast of current electrical standards (17th Edition).
• Safe working procedures which are both current and clearly documented.
Remember
Good employers, good managers and responsible employees with documented evidence of electrical compliance have nothing to fear.

 

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The Electricity at Work Regulations 1989


The Secretary of State, in exercise of the powers conferred on him by sections 15(1), (2), (3)(a) and (b), (4)(a), (5)(b), (6)(b), (8) and (9) and 82(3)(a) of, and paragraphs 1(1)(a) and (c), (2) and (3), 6(2), 9, 11, 12, 14, 15(1), 16 and 21(b) of Schedule 3 to, the Health and Safety at Work etc. Act 1974[1] ("the 1974 Act"), and of all other powers enabling him in that behalf and for the purpose of giving effect without modifications to proposals submitted to him by the Health and Safety Commission under section 11(2)(d) of the 1974 Act, after the carrying out by the said Commission of consultations in accordance with section 50(3) of that Act, hereby makes the following Regulations:

PART I : INTRODUCTION

Citation and commencement
1. These Regulations may be cited as the Electricity at Work Regulations 1989 and shall come into force on 1st April 1990.
Interpretation
2.—(1) In these Regulations, unless the context otherwise requires-
"approved" means approved in writing for the time being by the Health and Safety Executive for the purposes of these Regulations or conforming with a specification approved in writing by the Health and Safety Executive for the purposes of these Regulations;
"circuit conductor" means any conductor in a system which is intended to carry electric current in normal conditions, or to be energised in normal conditions, and includes a combined neutral and earth conductor, but does not include a conductor provided solely to perform a protective function by connection to earth or other reference point;
"conductor" means a conductor of electrical energy;
"danger" means risk of injury;
"electrical equipment" includes anything used, intended to be used or installed for use, to generate, provide, transmit, transform, rectify, convert, conduct, distribute, control, store, measure or use electrical energy;
"firedamp" means any flammable gas or any flammable mixture of gases occurring naturally in a mine;
"injury" means death or personal injury from electric shock, electric burn, electrical explosion or arcing, or from fire or explosion initiated by electrical energy, where any such death or injury is associated with the generation, provision, transmission, transformation, rectification, conversion, conduction, distribution, control, storage, measurement or use of electrical energy;
"safety-lamp mine" means-
(a) any coal mine; or
(b) any other mine in which-
(i) there has occurred below ground an ignition of firedamp; or
(ii) more than 0.25% by volume of firedamp is found on any occasion at any place below ground in the mine;
"system" means an electrical system in which all the electrical equipment is, or may be, electrically connected to a common source of electrical energy, and includes such source and such equipment.
(2) Unless the context otherwise requires, any reference in these Regulations to-
(a) a numbered regulation or Schedule is a reference to the regulation or Schedule in these Regulations so numbered;
(b) a numbered paragraph is a reference to the paragraph so numbered in the regulation or Schedule in which the reference appears.

Persons on whom duties are imposed by these Regulations
3.—(1) Except where otherwise expressly provided in these Regulations, it shall be the duty of every-
(a) employer and self-employed person to comply with the provisions of these Regulations in so far as they relate to matters which are within his control; and
(b) manager of a mine or quarry (within in either case the meaning of section 180 of the Mines and Quarries Act 1954[2]) to ensure that all requirements or prohibitions imposed by or under these Regulations are complied with in so far as they relate to the mine or quarry or part of a quarry of which he is the manager and to matters which are within his control.

(2) It shall be the duty of every employee while at work-
(a) to co-operate with his employer so far as is necessary to enable any duty placed on that employer by the provisions of these Regulations to be complied with; and
(b) to comply with the provisions of these Regulations in so far as they relate to matters which are within his control.

 

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PART II
GENERAL :

Systems, work activities and protective equipment
4.—(1) All systems shall at all times be of such construction as to prevent, so far as is reasonably practicable, danger.

(2) As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as is reasonably practicable, such danger.

(3) Every work activity, including operation, use and maintenance of a system and work near a system, shall be carried out in such a manner as not to give rise, so far as is reasonably practicable, to danger.

(4) Any equipment provided under these Regulations for the purpose of protecting persons at work on or near electrical equipment shall be suitable for the use for which it is provided, be maintained in a condition suitable for that use, and be properly used.
Strength and capability of electrical equipment
5. No electrical equipment shall be put into use where its strength and capability may be exceeded in such a way as may give rise to danger.
Adverse or hazardous environments
6. Electrical equipment which may reasonably foreseeably be exposed to-
(a) mechanical damage;
(b) the effects of the weather, natural hazards, temperature or pressure;
(c) the effects of wet, dirty, dusty or corrosive conditions; or
(d) any flammable or explosive substance, including dusts, vapours or gases,
shall be of such construction or as necessary protected as to prevent, so far as is reasonably practicable, danger arising from such exposure.
Insulation, protection and placing of conductors
7. All conductors in a system which may give rise to danger shall either-
(a) be suitably covered with insulating material and as necessary protected so as to prevent, so far as is reasonably practicable, danger; or
(b) have such precautions taken in respect of them (including, where appropriate, their being suitably placed) as will prevent, so far as is reasonably practicable, danger.
Earthing or other suitable precautions
8. Precautions shall be taken, either by earthing or by other suitable means, to prevent danger arising when any conductor (other than a circuit conductor) which may reasonably foreseeably become charged as a result of either the use of a system, or a fault in a system, becomes so charged; and, for the purposes of ensuring compliance with this regulation, a conductor shall be regarded as earthed when it is connected to the general mass of earth by conductors of sufficient strength and current-carrying capability to discharge electrical energy to earth.
Integrity of referenced conductors
9. If a circuit conductor is connected to earth or to any other reference point, nothing which might reasonably be expected to give rise to danger by breaking the electrical continuity or introducing high impedance shall be placed in that conductor unless suitable precautions are taken to prevent that danger.
Connections
10. Where necessary to prevent danger, every joint and connection in a system shall be mechanically and electrically suitable for use.
Means for protecting from excess of current
11. Efficient means, suitably located, shall be provided for protecting from excess of current every part of a system as may be necessary to prevent danger.
Means for cutting off the supply and for isolation
12.—(1) Subject to paragraph (3), where necessary to prevent danger, suitable means (including, where appropriate, methods of identifying circuits) shall be available for-
(a) cutting off the supply of electrical energy to any electrical equipment; and
(b) the isolation of any electrical equipment.

(2) In paragraph (1), "isolation" means the disconnection and separation of the electrical equipment from every source of electrical energy in such a way that this disconnection and separation is secure.

(3) Paragraph (1) shall not apply to electrical equipment which is itself a source of electrical energy but, in such a case as is necessary, precautions shall be taken to prevent, so far as is reasonably practicable, danger.
Precautions for work on equipment made dead
13. Adequate precautions shall be taken to prevent electrical equipment, which has been made dead in order to prevent danger while work is carried out on or near that equipment, from becoming electrically charged during that work if danger may thereby arise.
Work on or near live conductors
14. No person shall be engaged in any work activity on or so near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless-
(a) it is unreasonable in all the circumstances for it to be dead; and
(b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and
(c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.
Working space, access and lighting
15. For the purposes of enabling injury to be prevented, adequate working space, adequate means of access, and adequate lighting shall be provided at all electrical equipment on which or near which work is being done in circumstances which may give rise to danger.
Persons to be competent to prevent danger and injury
16. No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or, where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work.

 

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Earthing or other suitable precautions :

PART II :
GENERAL ,

Systems, work activities and protective equipment
4.—(1) All systems shall at all times be of such construction as to prevent, so far as is reasonably practicable, danger.

(2) As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as is reasonably practicable, such danger.

(3) Every work activity, including operation, use and maintenance of a system and work near a system, shall be carried out in such a manner as not to give rise, so far as is reasonably practicable, to danger.

(4) Any equipment provided under these Regulations for the purpose of protecting persons at work on or near electrical equipment shall be suitable for the use for which it is provided, be maintained in a condition suitable for that use, and be properly used.
Strength and capability of electrical equipment
5. No electrical equipment shall be put into use where its strength and capability may be exceeded in such a way as may give rise to danger.
Adverse or hazardous environments
6. Electrical equipment which may reasonably foreseeably be exposed to-
(a) mechanical damage;
(b) the effects of the weather, natural hazards, temperature or pressure;
(c) the effects of wet, dirty, dusty or corrosive conditions; or
(d) any flammable or explosive substance, including dusts, vapours or gases,
shall be of such construction or as necessary protected as to prevent, so far as is reasonably practicable, danger arising from such exposure.
Insulation, protection and placing of conductors
7. All conductors in a system which may give rise to danger shall either-
(a) be suitably covered with insulating material and as necessary protected so as to prevent, so far as is reasonably practicable, danger; or
(b) have such precautions taken in respect of them (including, where appropriate, their being suitably placed) as will prevent, so far as is reasonably practicable, danger.
Earthing or other suitable precautions
8. Precautions shall be taken, either by earthing or by other suitable means, to prevent danger arising when any conductor (other than a circuit conductor) which may reasonably foreseeably become charged as a result of either the use of a system, or a fault in a system, becomes so charged; and, for the purposes of ensuring compliance with this regulation, a conductor shall be regarded as earthed when it is connected to the general mass of earth by conductors of sufficient strength and current-carrying capability to discharge electrical energy to earth.
Integrity of referenced conductors
9. If a circuit conductor is connected to earth or to any other reference point, nothing which might reasonably be expected to give rise to danger by breaking the electrical continuity or introducing high impedance shall be placed in that conductor unless suitable precautions are taken to prevent that danger.
Connections
10. Where necessary to prevent danger, every joint and connection in a system shall be mechanically and electrically suitable for use.
Means for protecting from excess of current
11. Efficient means, suitably located, shall be provided for protecting from excess of current every part of a system as may be necessary to prevent danger.
Means for cutting off the supply and for isolation
12.—(1) Subject to paragraph (3), where necessary to prevent danger, suitable means (including, where appropriate, methods of identifying circuits) shall be available for-
(a) cutting off the supply of electrical energy to any electrical equipment; and
(b) the isolation of any electrical equipment.

(2) In paragraph (1), "isolation" means the disconnection and separation of the electrical equipment from every source of electrical energy in such a way that this disconnection and separation is secure.

(3) Paragraph (1) shall not apply to electrical equipment which is itself a source of electrical energy but, in such a case as is necessary, precautions shall be taken to prevent, so far as is reasonably practicable, danger.
Precautions for work on equipment made dead
13. Adequate precautions shall be taken to prevent electrical equipment, which has been made dead in order to prevent danger while work is carried out on or near that equipment, from becoming electrically charged during that work if danger may thereby arise.
Work on or near live conductors
14. No person shall be engaged in any work activity on or so near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless-
(a) it is unreasonable in all the circumstances for it to be dead; and
(b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and
(c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury.
Working space, access and lighting
15. For the purposes of enabling injury to be prevented, adequate working space, adequate means of access, and adequate lighting shall be provided at all electrical equipment on which or near which work is being done in circumstances which may give rise to danger.
Persons to be competent to prevent danger and injury
16. No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or, where appropriate, injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work.

 

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Legal Requirements :

The legislation of specific relevance to electrical maintenance is:
The Heath & Safety at Work Act : 1974 ,
The Management of Heath & Safety at Work Regulations : 1999 ,Every employer shall make suitable and sufficient The Electricity at Work Regulations : 1989 , The Workplace ( Heath & Safety and Welfare ) Regulations : 1992 , The Provision and Use of Work Equipment Regulations : 1998 ,
The Health & Safety at Work Act 1974 puts the duty of care upon both the employer and the employee to ensure the safety of all persons using the work premises. This includes the self employed.

The Management of Health & Safety at Work Regulations 1999 states:
'Every employer shall make suitable and sufficient assessment of:

(a) the risks to the health and safety of his employees to which they are exposed whilst at work, and

(b) the risks to ensure the health and safety of persons not in his employment arising out of or in connection with the conduct by him or his undertaking.'

The Provision and Use of Work Equipment Regulations 1998 states:

'Every employer shall ensure that work equipment is maintained in an efficient state, in efficient working order and in good repair.'

The PUWER 1998 covers most risks that can result from using work equipment. With respect to risks from electricity, compliance with the Electricity at Work Regulations 1989 is likely to achieve compliance with the PUWER 1998.The Management of Health & Safety at Work Regulations 1999 states:
PUWER 1998 only applies to work equipment used by workers at work. This includes all work equipment (fixed, transportable or portable) connected to a source of electrical energy. PUWER does not apply to fixed installations in a building. The electrical safety of these installations is dealt with only by the Electricity at Work Regulations.

The Electricity at Work Regulations 1989 states:

'All systems shall at all times be of such construction as to prevent, so far as reasonably practicable, such danger.'

'As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as reasonably practicable, such danger.'

'System' means an electrical system in which all the electrical equipment is, or may be, electrically connected to a common source of electrical energy and includes such source and such equipment'

'Electrical Equipment' includes anything used, intended to be used or installed for use, to generate, provide, transmit, transform, rectify, convert, conduct, distribute, control, store, measure or use electrical energy.'

Scope of the legislation

It is clear that the combination of the HSW Act 1974, the PUWER 1998 and the EAW Regulations 1989 apply to all electrical equipment used in, or associated with, places of work. The scope extends from distribution systems down to the smallest piece of electrical equipment.

It is clear that there is a requirement to inspect and test all types of electrical equipment in all work situations. at work, and

(b) the risks to ensure the health and safety of persons not in his employment arising out of or in connection with the conduct by him or his undertaking.'

The Provision and Use of Work Equipment Regulations 1998 states:

 

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-&- 2330
Syllabus for the Level 2 Certificate in Electrotechnical Technology :

Introduction to Electrical Installation Work

This Chapter describes safe systems of working and the principle of operation of some electrical machines, equipment and systems.

Health and Safety Applications Avoiding Accidents in the Workplace
The Health & Safety at Work Act 1974 places a statutory and common law obligation on employers to take
reasonable care of the health and safety of their workers. The Management of Health & Safety at Work
Regulations 1999 places an obligation on employers to carry out “risk assessments” and, where necessary, to
take action to eliminate or control risks. The Workplace(Health, Safety and Welfare) Regulations 1992 and the
Construction Health, Safety and Welfare Regulations1996 cover all aspects of the workplace and construction
sites respectively. They include the requirement that all areas where people could fall from a height of two metres or above, are properly guarded. The latest HSE Regulations “Working at Height” were introduced in April 2005. The aim of these Regulations is to avoid working at height, if possible, but where this cannot be avoided, to use the best practicable means of ensuring the safety of those working at height. However, despite all the legislation, we know from the HSE statistics that accidents still occur in the workplace. The most common causes of accidents in the workplace are:
◆ slips, trips and falls
◆ manual handling, that is, moving objects by hand

Healthy and Safety Application and Electrical Principles :

Slips, trips and falls are the most common causes of accidents in the workplace

◆ using equipment, machinery or tools
◆ storage of goods and materials which then become unstable and fall on someone
◆ fire
◆ electricity
◆ mechanical handling To control the risk of an accident we usually:
◆ eliminate the cause, that means, do not do the job or procedure in an unsafe way

Introduction to Electrical Installation Work :

◆ substitute a procedure or product with less risk, that means finding a safer way to complete the job or procedure
◆ enclose the dangerous situation, that means fitting guards or screening off an area and only allowing trained and competent people into a potentially dangerous area
◆ put guards around a hazard, for example, placing guards in front of cutting and grinding wheels
◆ use safe systems of work, that means establishing written procedures for work that is potentially dangerous. These written procedures are sometimes called ‘permits to work’
◆ supervise, train and give information to staff which leads to a ‘competent’ workforce
◆ if a hazard cannot be removed or minimised, then the employer must provide PPE. However, providing personal protective equipment to staff must be a last resort when the hazard cannot be removed in any other way. The PPE must be provided at the employer’s expense

A Hazard is something with the potential to cause harm; for example, electric tools, working above ground level, wet or uneven floors, rotating parts. A Risk is the possibility of harm actually being

A Risk is the possibility of harm actually being done. Is it a high, low or medium risk ? Who is at risk,
done. Is it a high, low or medium risk? Who is at risk the office staff, electricians, the public ? Is the risk adequately controlled ?

A positive, personal attitude to safety reduces accidents at work. Always work and act responsibly

Healthy and Safety Application and Electrical Principles :

and safely to protect yourself and others. Be aware of the hazards around you, the protection available to you and the means of preventing accidents.

Risk Assessment, the Process
We have already said that an employer must carry out risk assessments as a part of a robust Health and
Safety policy. The HSE recommends five steps to any risk assessment.

Step 1

Look at what might reasonably be expected to cause harm. Ignore the trivial and concentrate only on significant hazards that could result in serious harm or injury. For example:
◆ Slipping, tripping or falling hazards, e.g. from poorly maintained or partly installed floors and stairs
◆ Fire, e.g. from flammable materials you might be using such as solvents
◆ Rotating parts of hand tools, e.g. drills
◆ Accidental discharge of cartridge operated tools
◆ Manual handling, e.g. lifting, moving or supporting loads

Step 2
Decide who might be harmed, do not list individuals by name. Just think about groups of people

Healthy and Safety Application and Electrical Principles

LEVEL 3 - UNIT 1 - MOCK EXAMINATION, Application of health and safety and electrical principles:

What does fire legislation require all public buildings, factories and hospitals to have ?
** fire warning systems and fire fighting equipment
fire marshals in each department
first aid posts on all floors
fire proof clothing and equipment on site

In order to prevent the risk of electric shock when working on a control panel, what action should be taken ?
** isolate and lock-off the supply
operate the emergency stop
disconnect the entire installation
switch off the supply at the switch

Under what conditions is increased profitability most likely to occur ?
** if customer satisfaction is sustained
if higher purchase prices are charged
if retail profits are reduced
if employer salaries are reduced

What is the effect of an inductive load on an AC supply ?
power factor lead
power factor unity
no effect
** power factor lag

What is the primary function of a fuse ?
to protect against motor start-up currents
** to protect circuit conductors from damage
to protect appliances connected in the circuit
to protect against electric shock

How can the direction of rotation be changed on a single phase capacitor start induction motor ?
add a capacitor in parallel to the supply
reverse the supply connections to the motor
reverse the capacitor connections
** reverse the connections to the start winding

How can accidents in the workplace be reduced ?
supply more fire fighting equipment
clearly mark all exit signs
** provide safety education and publicity
supply more first aid posts

Which electronic component has the function of detecting changes in light levels ?
thyristor
** photo transistor
fibre optic cable
opto coupler

What type of safety sign is displays a white pictogram on a blue coloured background ?
** mandatory
safe condition information
warning
prohibition

Minimum wage payment and claims for unfair dismissal are rights under which act ?
data protection act
human rights act
** employment rights act
race relations act

What does the development of new technology in the electrotechnical sector require ?
moving employees into less technical roles
preparing employees for possible redundancy
a need to employ younger members of staff
** a need for continual retraining and development

What cable type is used for underground power distribution ?
HOFR
MIMS
LSF
*** PILCSWA

A work colleague has suffered an electric shock, and has no pulse. The appropriate action is to...
place the victim in the recovery position and dial 999
** perform chest compressions and mouth-to-mouth resuscitation
loosen the victims clothing and call 99
perform mouth-to-mouth resuscitation

An inductive load with 10 ohms inductive reactance is connected to a 100v 50 Hz AC supply. Calculate the power dissipated in the circuit ( ignoring any conductor resistance.)
** 0kW
1kW
1W
100W

How are the electrical connections made to the rotor of a 3-phase wound rotor induction motor ?
direct connection
commutator
via magnetic connection
** slip rings

What term is used to describe the ability of a capacitor to store a charge ?
volume
charge
capacitive reactance
** capacitance

What does the development of new technology in the electrotechnical sector require ?
a need to employ younger members of staff
** a need for continual retraining and development
preparing employees for possible redundancy
moving employees into less technical roles

The HASAW 1974 act details the basis for how ?
** employers safeguard the health and safety of their employees
employers can reduce any responsibility regarding health and safety in the workplace
how to work in a hazardous work situation without the need for PPE
employees can gain compensation for any accident in the workplace

Which one of the following gases is heavier than air and can cause asphyxiation ?
** methane
helium
hydrogen
nitrogen

By what method are small 3-phase cage rotor induction motors started ?
star/delta starter
** DOL starter
rotor resistance starter
autotransformer starter

Which one of the following is the most common earthing system in the UK ?
** TN-S
TT
TNC-S
TN-C

What is the name given to a person in a company who represents other workers on matters of safety ?
health and safety officer
** safety representitive
safety officer
company nurse

What is the term used to describe the satisfactory performance of systems or equipment ?
fit and performs well
** fit for purpose
performs with minimal maintenance
performs well at all times

What type of machine is a capacitor start capacitor run motor ?
wound rotor machine
3-phase machine
** single phase machine
synchronous machine

The current in a coil changes from 5 amperes to 2 amperes in 50mS and induces a voltage of 30v into the coil. Calculate the value of the inductance of the coil. ?
3H
1.1H
** 0.5H
0.1H

Minimum wage payment and claims for unfair dismissal are rights under which act ?
race relations act
** employment rights act
data protection act
human rights act

 

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Calculate the synchronous speed of the rotating magnetic field in a 4-pole synchronous motor ?
750rpm
3000rpm
1200rpm
** 1500rpm

What are the running characteristics of a 3-phase cage-rotor induction motor under constant load ?
it runs above synchronous speed
it runs at various speeds
** it runs at constant speed
it runs at synchronous speed

Calculate the inductive reactance of a coil with inductance of 0.1H, connected to a 50Hz AC supply. ?
314.2 ohms
3.142 ohms
0.3142 ohms
** 31.42 ohms

A 3-phase 4-wire balanced load is connected to a 3-phase 4-wire supply. Each phase draws 65A from the supply. Calculate the neutral current ?
6.15A
195A
65A
** 0A

A transformer has 1000v (V pri) and 200v (V sec). If current (pri) is 5A, calculate the secondary current ?
** 25A
10A
5A
1A

If a fault occurs in electrical equipment and has the potential to cause harm to employees, what term describes this ?
industrial malfunction
equipment danger
** dangerous occurance
maintenance fault

To what process do the terms storming, norming, forming and performing apply ?
** problem solving
staff organisational restructuring
company manufacturing processes
staff training


Who issues a permit to work ?
a qualified first aider
the tradesperson doing the work
** suitable responsible person
HSE


How is the primary earth connection made on a TT earthing system ?
combined earth/neutral conductor
metallic sheath of the supply cable
utilisation of water and gas pipes
** earth rod into the ground

When should loose clothing or ties not be worn by an employee ?
** when operating rotating machinery
when performing safe isolation
when disconnecting electrical supplies
when working with toxic materials

What is the process of preparing a report on potential health and safety hazards called ?
accident assessment
risk survey
** risk assessment
health survey

Under what fault conditions does a RCD operate ?
phase to neutral fault
** phase to earth fault
open circuit in an earth conductor
open circuit fault in a phase conductor



PPE is provided by an employer, however, it is the responsibility of the employee to ?
report any damaged PPE to the HSE
not to use damaged PPE whilst doing the job
continue to use damaged PPE until it can be replaced
** inspect all PPE before and after use

The peak-to-peak voltage of a sinusoidal waveform is ?
peak
4 x peak
0.5 x peak
** 2 x peak

manual handling regulations

More than a third of all accidents formally reported each year relate to manual handling legislation, the vast majority being ‘over three day’ injuries, most commonly sprains or strains, often of the back. Risks from workplace manual handling tasks are linked to many factors.

Manual handling regulation covers transporting a load and supporting a load in a static posture using the hands or any other part of the body, such as the shoulder. It also includes the intentional dropping or throwing of a load, whether into a container or from one person to another.

Good practice for manual handling health and safety requires employers to avoid manual handling as far as reasonably practicable. They should make a manual handling risk assessment of any hazardous operations that cannot be avoided and reduce risk as far as reasonably practicable and employers need to be up to date with the latest manual handling legislation

Accidents in the workplace

Industrial accident safety information
Workplace accidents are unplanned events (possibly resulting from management failure) that can cause death, injury, pain and suffering to employees, their families, work colleagues and sometimes members of the public.

According to the HSE, over 200 workers and over 300 members of the public die as a result of workplace accidents, over 150,000 injuries to employees are reported under RIDDOR (nearly 6 in every 1,000 employees) of which 40 per cent of these accidents occurred during activities related to manual handling.

Safety in the workplace is a priority because, as well as the human cost, the financial cost associated with accidents in the workplace can be considerable for both the injured person and the employer. Employers are obliged to anticipate danger that could lead to an industrial accident. Safety will be increased if companies follow workplace accident advice by systematically assessing risks and recording the findings.

Incidents (accidents which do not cause injury) are an important learning opportunity and understanding why they occurred can help prevent injury accidents taking place. Understanding and rectifying what causes accidents is an important part of health and safety management.

slips trips and falls

Over a third of all major injuries reported each year are caused as a result of a slip, trip or fall.

Injuries caused by slips, trips and falls are the single most common cause of injuries at work and these accidents cost employers over £500 million a year in lost production and other costs. The risks of employees slipping, tripping or falling should therefore be assessed as part of your general risk assessments.

noise and vibration

Noise affects a wide variety of businesses. When noise is too loud, for too long, it can damage the delicate mechanism of the inner ear, destroying sensitive nerve cells. If you find it difficult to hold a conversation in the workplace, without shouting when standing 2m away from another person, you are likely to have a noise problem.


Hand-arm vibration (HAV) is vibration transmitted from work processes into the hands and arms. It can be caused by operating hand-held power tools, or by holding materials being processed by machinery. Regular and frequent exposure to high levels of vibration can lead to permanent injury. Regular exposure to HAV can cause a range of permanent injuries to hands and arms, collectively known as hand-arm vibration syndrome (HAVS).

working environment

Health and safety in the day-to-day working environment
Workplace safety encompasses everyone from office to factory workers, whether you’re sat at a desk all day or working out in the fields. We spend longer at work than in almost any other situation and location, and how we work can have a huge impact on our own wellbeing.

Health and safety in the workplace is of paramount importance, not only because health and safety at work legislation places obligations on employers and employees, but because you will optimise productivity if you identify and deal with risks before they cause an adverse impact on any individual in the workplace.

Health and safety regulations require you to take action in response to particular hazards such as working at height, the potential for musculo-skeletal disorders, and the risk of slips, trips and falls.

A clear health and safety policy, backed up by effective procedures, will show your employees you have a genuine emphasis on workplace health and safety. A proactively-managed workplace will enable you to minimise the risk, whether it’s an office or a factory, and maximise the opportunities for your employees.

 

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The impact of the amended Work at Height Regulations : May 2008

With the amended Work at Height Regulations now beginning to bite, employers, employees and contractors can no longer just reach for the nearest set of ladders or steps to gain access at height - they must now carry out risk assessments, a method statement and consider whether an alternative form of access would be safer.

Let's make one thing clear - the regulations do not ban ladders, but they do oblige you to ensure that ladders are not an automatic choice and that alternatives should always be considered.
The choice of access equipment will be determined by the height to be negotiated, the site conditions, the duration and extent of work, and the frequency of required access.

Where a risk assessment highlights the need for a powered access platform, hirers will find them to be quick, convenient to use and easily manoeuvrable - increasing productivity for companies.

The Work at Height regulations bring together all existing work at height regulations and state the minimum requirements for the use of equipment. Although previous regulations applied primarily to work over two metres, the new regulations even cover standing on the bottom rung of a small step ladder.
Employers have a duty of care to ensure that work at height is properly planned, appropriately supervised and carried out in a safe manner. All employers, the self-employed and any other person who controls the work of others should be fully up to date with the new legislation. This includes site managers, contract managers, contractors, and even the building owner who contracts others to work at height.
Employers should particularly note two key areas in the Work at Height Regulations, regulation four and regulation six. Regulation four covers organisation and planning. It states that every employer shall ensure that work at height is:
** Properly planned. You should carry out a risk assessment and have a written system of work. This will only prevent accidents, however, if it is passed on to the employees.
** Appropriately supervised. What experience do your employees have? Are your apprentices competent?
**Carried out in a manner which is, so far as is reasonably practicable, safe. Common
** sense has to be used here - cost or history will never be an acceptable excuse.

Regulation 6 - the avoidance of risks from work at height - ensures that the areas above are complied with. It states: "In identifying the measures required by this regulation, every employer shall take account of a risk assessment under regulation three of the Management Regulations. Every employer shall ensure that work is not carried out at height where it is reasonably practicable to carry out the work safely otherwise than at height."
It is essential to ensure that you take time in the planning and conformity of future works. To assist us in compliance with this regulation the British Standard Institute has published a code of practice (BS 8437:2005) for selection, use and maintenance of personal fall protection systems and equipment for use in the workplace. It brings together best practice in personal fall protection.

Requirements on employers

Most importantly, employers must follow all that is reasonably practicable to prevent anyone from falling. To do so, the regulations define a hierarchy of requirements that duty holders must follow. Duty holders must:
• Avoid work at height where they can.
• Use work equipment or other measures to prevent falls where they cannot avoid working at height.
• Where the risk of a fall cannot be eliminated, use work equipment or other measures to minimise the distance and consequences of a fall should one occur.
Concretely, dutyholders must ensure that:
• All work at height is properly planned and organised.
• Weather conditions are taken into consideration.
All those involved in work at height are trained and competent. This includes that those who will be working at height are trained how to avoid falling, and how to avoid or minimise injury should they fall.
• Equipment is properly inspected.
• The risks from fragile surfaces are properly controlled.
• The risks from falling objects are properly controlled (e.g. nothing should be thrown or tipped from height if it can injure anyone).
• Each individual place at which work at height is done is checked every time before that place is used. This includes that any platform used for or for access to construction work from which a person could fall more than two meters is inspected in place before it is used.

Requirements on employees

Note that also employees have to contribute to minimising the risk from working at height. All employees and all those working under someone else’s control must:
• Report any safety hazards to them.
• Use the equipment supplied to them properly and follow any training and instruction.
• If you think that following some instructions is unsafe, do seek further advice before continuing. Also bring the situation to the attention of your UCATT safety rep.

What is Work at Height ?

There is a quite simple definition for what working ‘at height’ means: a place is ‘at height’ if a person could be injured falling from it.

Advice for workers: ladder safety
In the construction industry numerous falls take place in conjunction with ladders and scaffolding. It therefore is of major importance that contractors, designers and clients make efforts at a very early stage of a project in order to reduce the time that workers need to use access equipment like ladders or scaffolding.
Note that ladders can be used where a risk assessment shows a low risk and where the duration of usage is short, i.e. not more than 15-30 minutes depending on the task, as well as where a situation requires its usage.
If you have to use a ladder, follow the below guidance which helps you to reduce the most common types of falls.

Check the ladder before using it
It is important that the condition of a ladder is checked before using it. Detailed information on how to check leaning and step ladders are contained at the .
In order not to fall off a ladder:
• Keep your body centered within the ladder.
• Always keep three points of contact with the ladder.
• Wear non-slip footwear, clean the soles of shoes if dirty.
• Keep the rungs clean and in good condition.

In order to prevent the ladder wobbling, slipping and falling:
• Position the ladder correctly on a firm, level surface.
• Check the feet of the ladder daily.
• Fasten the ladder at top and bottom.
• Rest the ladder on a firm surface at the top.

In order to prevent the ladder from breaking:
• Do not exceed the maximum weight limit on the ladder.
• Position the ladder properly at an angle of 75 degree (equivalent to the “1 in 4 rule”: feet of the ladder must be one unit away from hold for every 4 units up)
• Only carry light materials or tools (up to 10kg).
Always speak to your supervisor, employer or safety rep if you think it is not right to use a ladder for the job.

Safe use of ladders and stepladders :

An employers’ guide

* know when to use a ladder;

* decide how to go about selecting the right sort of ladder for the particular job;


* understand how to use it;


* know how to look after it; and


* take sensible safety precautions.


2 HSE believes that misuse of ladders at work can be partly explained by the way they are used in the home. As with all work equipment, users need adequate information and training to be able to use ladders and stepladders safely. Adequate supervision is needed so that safe practices continue to be used.


3 This guidance does not apply to fixed ladders (on buildings, plant or vehicles), other types of fixed access (step irons etc), specialist rescue ladders used by the fire service, roof ladders, step stools, warehouse steps/mobile stairs, or temporary or permanent stairs.


When is a ladder the most suitable access equipment ?


4 This selection process has to take into account the hierarchy of controls:1

* firstly to avoid work at height where possible;
* then to prevent falls from height; and, failing that,

* to reduce the consequences of a fall.


5 Where work at height is necessary you need to justify whether a ladder or stepladder is the most suitable access equipment compared to other access equipment options. You do this by using risk assessment and the hierarchy of controls.

6 When considering whether it could be appropriate to use a ladder or stepladder, you need to consider the following factors.

 

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Is it a suitable activity?
7 This refers to the type of work and its duration. As a guide, only use a ladder or stepladder: * in one position for a maximum of 30 minutes; * for ‘light work’ - they are not suitable for strenuous or heavy work. If a task involves a worker carrying more than 10 kg (a bucket of something) up the ladder or steps it will need to be justified by a detailed manual handling assessment;
* where a handhold is available on the ladder or stepladder; * where you can maintain three points of contact (hands and feet) at the working position. On a ladder where you cannot maintain a handhold, other than for a brief period of time, other measures will be needed to prevent a fall or reduce the consequences of one. On stepladders where a handhold is not practicable a risk assessment will have to justify whether it is safe or not (see paragraph 10 for details).
8 On a ladder or stepladder do not: * overload it - the person and anything they are taking up should not exceed the highest load stated on the ladder; * overreach - keep your belt buckle (navel) inside the stiles and both feet on the same rung throughout the task

9 When working on stepladders you should avoid work that imposes a side loading, such as side-on drilling through solid materials (e.g. bricks or concrete), by having the steps facing the work activity , Where side-on loadings cannot be avoided you should prevent the steps from tipping over, for example by tying the steps to a suitable point. Otherwise a more suitable type of access equipment should be used.

10 You should also avoid holding items when climbing (for example by using tool belts): * on a ladder where you must carry something you must have one free hand to grip the ladder; * on a stepladder where you cannot maintain a handhold (e.g. putting a box on a shelf), the use of a stepladder will have to be justified by taking into account:

- the height of the task;
- a safe handhold still being available on the stepladder;
- whether it is light work
- whether it avoids side loading
- whether it avoids overreaching
- whether the user’s feet are fully supported; and
- whether you can tie the stepladder

> Is it a safe place to use a ladder or stepladder ?

13 This covers the specific place where you are going to set up and use it. As a guide, * only use a ladder or stepladder: on firm ground or spread the load (e.g. use a board); * on level ground - for stepladders refer to the manufacturer’s instructions, for ladders the maximum safe ground slopes on a suitable surface (unless the manufacturer states otherwise) are as follows:
- side slope 16o – but the rungs still need to be levelled
- back slope 6º * on clean, solid surfaces (paving slabs, floors etc). These need to be clean (no oil, moss or leaf litter) and free of loose material (sand, packaging materials etc) so the feet can grip. Shiny floor surfaces can be slippery even without contamination; * where it has been secured.
14 The options for securing a ladder are as follows: * tie the ladder to a suitable point, making sure both stiles are tied, * where this is not practical, use a safe, unsecured ladder or a ladder supplemented with an effective ladder stability device * if this is not possible, then securely wedge the ladder, e.g. against a wall; * if none of the above can be achieved, foot the ladder. Footing is the last resort and should be avoided, where reasonably practicable, by the use of other access equipment.
15 Ladders used for access to another level should be tied . Stepladders should not be used for access to another level unless they have been designed for this.
16 Consider tying a stepladder where possible and advantageous to the task (e.g. side-on working or where two free hands are needed).

 

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17 You should only use ladders or stepladders: * where they will not be struck by vehicles, by protecting them with suitable barriers or cones; * where they will not be pushed over by other hazards such as doors or windows, by securing doors (not fire exits) and windows where possible. If this is impractical, have a person standing guard at a doorway, or inform workers not to open windows until they are told to do so; * where pedestrians are prevented from walking under them or near them, by using barriers, cones or, as a last resort, a person standing guard at the base; * where ladders can be put up at the correct angle of 75o. To judge the angle use the angle indicator marked on the stiles of some ladders or the 1 in 4 rule (1 unit out for every 4 units up , * where the restraint devices on stepladders can be fully opened. Any locking devices must also be engaged.
18 On a ladder or stepladder: * don’t work within 6 m horizontally of any overhead power lines, unless the line owner has made them dead or protected with temporary insulation. If this is a regular activity, find out if the lines can be moved; * always use a non-conductive ladder or steps for any necessary live electrical work; * don’t rest ladders against weak upper surfaces (e.g. glazing or plastic gutters). Alternatively, you can use effective spreader bars or effective stand-offs ,
Is the ladder or stepladder safe to be used ? 19 Establish the ladder or stepladder is in a safe condition before using it. As a guide, only use ladders or stepladders that: * have no visible defects. They should have a pre-use check each working day; * have a current detailed visual inspection. These should be done in accordance with the manufacturer’s instructions. Ladders that are part of a scaffold system still have to be inspected every seven days; * are suitable for work use. Use Class 1 or EN 1314 ladders or stepladders at work because domestic (Class 3 ) ones are not normally suitable for use at work; * have been maintained and stored in accordance with the manufacturer’s instructions.
> What are pre-use checks and detailed visual inspections ? 20 Both are looking for obvious visual defects, they only differ in detail. Both can be done in-house (pre-use checks should be part of a user’s training). Detailed visual inspections should be recorded. Ladder stability devices and other accessories should be pre-use checked and inspected in accordance with the , manufacturer’s instructions. Ladder and stepladder feet must be part of the pre-use check. Ladder feet are essential for preventing the base of the ladder slipping. Missing stepladder feet cause it to wobble. The feet should be: * in good repair (not loose, missing, splitting, excessively worn, secure etc); and * clean – the feet should be in contact with the ground.

21 Ladder feet should also be checked when moving from soft/dirty ground (e.g. dug soil, loose sand/stone, a dirty workshop) to a smooth, solid surface (e.g. paving slabs), to ensure the foot material and not the dirt (e.g. soil, embedded stones or swarf) is making contact with the ground.
Do my ladder-users know how to use them safely ?
22 These are common issues about setting up and using ladders under the direct control of the user. Users should also be aware of the limitations covered in the other headings. People should only use a ladder, stepladder or stability device if:

* they are competent - users should be trained and instructed to use the equipment safely; * the ladder or stepladder is long enough -
for ladders:
- don’t use the top three rungs);
- ladders used for access should project at least 1 m above the landing point and be tied; alternatively a safe and secure handhold should be available;
for stepladders:
- don’t use the top two steps of a stepladder, unless a suitable handrail is available on the stepladder ;
- don’t use the top three steps of swing-back or double-sided stepladders, where a step forms the very top of the stepladder * the ladder or stepladder rungs or steps are level. This can be judged by the naked eye. Ladders can be levelled using specially designed devices but not by using bits of brick or whatever else is at hand; * the weather is suitable - do not use them in strong or gusting winds (follow the manufacturer’s safe working practices); * they are wearing robust, sensible footwear (e.g. safety shoes/boots or trainers). * Shoes should not have the soles hanging off, have long or dangling laces, or be thick with mud or other slippery contaminants; * they know how to prevent members of the public and other workers from using them; * they are fit - certain medical conditions or medication, alcohol or drug abuse could stop them from using ladders. If you are in any doubt, speak to an occupational health professional; * they know how to tie a ladder or stepladder properly.

23 On a ladder or stepladder, don’t:
* move them while standing on the rungs/steps;
* support them by the rungs or steps at the base;
* slide down the stiles;
* stand them on moveable objects, such as pallets, bricks, lift trucks, tower * scaffolds, excavator buckets, vans, or mobile elevating work platforms;
* extend a ladder while standing on the rungs.

Ladders guidance

* Prevented from slipping,
* Prevented from moving before it is stepped on,
* Long enough to do the job safely,
* Have a handhold available to allow the worker to maintain 3 points of contact where possible,
* Used without overreaching,
* Inspected and checked regularly where necessary.

 

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A toolbox talk

You do not need to fall from a great height to be badly injured. More people get injuries such as broken arms or
legs falling less than 2 m from a ladder than falling from above this height. For example, a person was killed when
they lost their footing on the second rung of a ladder and fell backwards, hitting their head on the floor.

* If the top of a ladder is 6 m up a wall how far out from the wall should the base be ? ( 1.5 m )

* Don’t stand on the top three rungs. Always try and make sure a ladder extends at least 1 m (or three rungs)
above where you will be working.

* If you are using a ladder for access, make sure it to at least 1 m (or three rungs) above the landing place. But
make sure it does not project so far above that it could pivot around the landing point.

* Don’t carry heavy or awkward shaped objects on a ladder. Never carry loads heavier than 25 kg - any over
10 kg should be avoided if possible. This includes long lengths of lightweight material such as plastic guttering,
which can be passed up by a second person instead. ( Where toolbelts have been issued , explain that they are to avoid having to carry tools by hand up and down a ladder )

Changes for 2009

The Hazardous Waste (England and Wales) Regulations 2005 were amended on 6 April 2009. This principally widened the scope of the exemption from hazardous waste :

The construction heath & Safety and Welfare Regulations 1996

1. Section 2 (1) of the Health and Safety at Work etc Act 1974 states: It shall be the duty of every employer to ensure, so far as is reasonably practicable, the health, safety and welfare at work of all his employees.
2. Section 3(1) of the Health and Safety at Work etc Act 1974 states: It shall be the duty of every employer to conduct his undertaking in such a way as to ensure, so far as is reasonably practicable, that persons not in his employment who may be affected thereby are not thereby exposed to risks to their health or safety.
3. Regulation 4(1) of the Construction (Health, Safety and Welfare) Regulations 1996 states: Subject to paragraph (5), it shall be the duty of every employer whose employees are carrying out construction work and every self-employed person carrying out construction work to comply with the provisions of these Regulations insofar as they affect him or any person at work under his control or relate to matters which are within his control

 

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Re: Section - 301- Questions - Testing ,

Passing an ECS Health and Safety Assessment is ↔ Compulsory ↔
→→→ For all you Chaps Renewing you ( J.I.B. Card ) ←←← 13 . 11 . 09

 

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Electrical Fundamentals : ( we all take for granted the fundaments ) !!!!!!
Two Current Flow theories exist. The first is:

“ELECTRON THEORY”
The Electron Theory states that current flows from NEGATIVE to POSITIVE. Electrons move from atom to atom as they move through the conductor towards positive.

The second Current Flow theory is:

“CONVENTIONAL THEORY”
Conventional theory, also known as HOLE THEORY, states that current flows from POSITIVE to NEGATIVE. Protons or the lack of electrons (the holes) move towards the negative. (Current flow direction in Hole Theory is the opposite of that in Electron Theory.)

“VOLTAGE”
Voltage is the electrical force that moves electrons through a conductor. Voltage is electrical pressure also known as EMF (Electro Motive Force) that pushes electrons.

The greater the difference in electrical potential push (difference between positive and negative), the greater the voltage force potential. ( Voltage is pressure )

“MEASUREMENT”
A VOLTMETER measures the voltage potential across or parallel to the circuit.

The Voltmeter measures the amount of electrical pressure difference between two points being measured.
Voltage can exist between two points without electron flow.

“CURRENT” (AMPERES)
CURRENT is the quantity or flow rate of electrons moving past a point within one second. Current flow is also known as amperage, or amps for short.

Higher voltage will produce higher current flow, and lower voltage will produce lower current flow.

“AFFECTS OF CURRENT FLOW”
Two common effects of current flow are Heat Generation and Electromagnetism.

HEAT: When current flows, heat will be generated. The higher the current flow the greater the heat generated. An example would be a light bulb. If enough current flows across the filament, it will glow white hot and illuminate to produce light.

ELECTROMAGNETISM: When current flows, a small magnetic field is created. The higher the current flow, the stronger the magnetic field. An example: Electromagnetism principles are used in alternators, ignition systems, and other electronic devices.

“RESISTANCE”
Resistance is the force that reduces or stops the flow of electrons. It opposes voltage.

Higher resistance will decrease the flow of electrons and lower resistance will allow more electrons to flow. ( Voltage → Résistance ↑ Current → )

RESISTANCE FACTORS
Various factors can affect the resistance. These include:

LENGTH of the conductor. The longer the conductor, the higher the resistance.

DIAMETER of the conductor. The narrower the conductor, the higher the resistance.

TEMPERATURE of the material. Depending on the material, most will increase resistance as temperature increases.

PHYSICAL CONDITION (DAMAGE) to the material. Any damage will increase resistance.

TYPE of MATERIAL used. Various materials have a wide range of resistances.

TYPES OF ELECTRICITY
Two basic types of Electricity classifications:

STATIC ELECTRICITY is electricity that is standing still. Voltage potential with NO electron flow.

DYNAMIC ELECTRICITY is electricity that is in motion. Voltage potential WITH electron flow. Two types of
Dynamic electricity exist:

Direct Current (DC) Electron Flow is in only one direction.

Alternating Current (AC) Electron flow alternates and flows in both directions (back and forth).

DYNAMIC ELECTRICITY
is electricity in motion, meaning you have electrons flowing, in other words voltage potential WITH electron flow.

Two types of dynamic electricity exists:

Direct Current (DC)

Alternating Current (AC)

DIRECT CURRENT (DC)
Electricity with electrons flowing in only one direction is called Direct Current or DC.

ALTERNATING CURRENT (AC)
Electricity with electrons flowing back and forth, negative - positive- negative, is called Alternating Current, or AC.

Wire sizing :

The longer the cable and the smaller the diameter, the higher the resistance : The shorter the cable and the larger the diameter the lower the resistance :

 

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* yellow warning signs comply with the standard design for all warning signs, comprising a yellow triangle with a black border and black graphics. These familiar, bright yellow signs always indicate potential hazards.

* The Warning High Sound Levels Wear Ear Protection sign is a useful way of informing people of the potential risk to their hearing and making sure that they wear the appropriate protection to prevent any possible damage.

Fire Exit Signs Green Safe Condition signs show your employees, visitors, customers, contractors and anyone else on your premises the location of fire safety equipment, and most importantly, the location of fire exits

* A pictogram plus the words FIRE EXIT indicate a specific fire exit route to be used during an evacuation

* The pictogram plus the single word EXIT is only used to indicate the conventional route out of the building

* Running Man Left : Sign

The Running Man Left / Right , sign will advise people to head for a nearest exit. This sign can also be used to symbolise an actual fire exit. It is always a good idea to make sure that all emergency exits are marked clearly so that there would not be any confusion during an actual emergency.

* Arrow Diagonal :
The Arrow Diagonal sign will be recognisable to people, for them to follow, in order to exit a building or to head towards an emergency exit. People often need regular directions, especially at times of emergency and this type of sign can prevent people from panicking unnecessarily.

* Hanging Fire Exit Right Up :
The Hanging Fire Exit Right Up sign will attach to a ceiling and direct people to the nearest fire exit. The sign is ideal as it is visible from both directions along a hall or corridor. The arrow on the right of the sign points to the top corner and this can be a good way of instructing to head up stairs and to the right.

* Hanging Wheelchair Fire Exit
The Hanging Wheelchair Fire Exit Right sign will be hung from the ceiling to advise people in wheelchairs of the location of their nearest fire exit. This sign is ideal as it can be seen by people that are coming from both directions.

Do not presume that people will automatically know the locations of fire exits, especially those in wheelchairs, use this sign to make sure that they remain safe. It will glow in the dark too,

* NHS Estates Signs
NHS estate fire safety signs must comply with the NHS Wayfinding & Signing Systems Guidance for Healthcare Facilities.
NHS estate fire exit and exit signs are similar to the conventional green safe condition signs found in every public building. All such signs are designed to help staff, patients and visitors to locate fire exits in hospitals, clinics, surgeries and other healthcare facilities both quickly and easily.
NHS estate signs feature an additional pictogram of flames alongside the standard BS-5499 running man, in order to present a clear, unequivocal message.

Assembly Point Signs
Like all our green fire safety signs, all assembly point signs at Simply Safety Signs comply with the British Standard Code of Practice for safety signs (BS 5499-10:2006). The Code states that all signs must:
* Provide information in a compact form
* Provide information in a form that is independent of language
* Have visual impact
* Guide the viewer to a desired outcome or appropriate decision
* Our assembly point signs are designed to be as clear and direct as possible. The

* Assembly Point
The Assembly Point sign will provide people with a clear guidance of the fact that they have reached a safe assembly point. People will usually have been notified of the directions to an assembly point beforehand and this sign provides clarification of the fact that they have reached the correct place for them to be.

You should remember that during an emergency especially, people will require reassurance of the fact that they have reached a safe place, well away from any danger.

* Emergency Lighting Stickers
When the power fails and all that remains is emergency lighting, it is vital that anyone on your premises can see all fire exit and emergency exit signs.
self-adhesive legend stickers are designed to stick to any standard emergency light fitting, either wall mounted or hanging luminaires, with a white legend on a green background for maximum effect. the light shines through the white parts, whilst the green part colours the light to make the white letters stand out better!
* Physical Warning Signs
A physical warning sign is designed to alert your workers, guests and anyone else on your premises to potential risks in their immediate environment. From hot water to wet floors, 'Mind the step' to 'Mind your head', it's always better to risk stating the obvious with a warning sign to gambling on people having 'common sense'!
warning signs are designed to alert readers to less obvious risks too, such as incomplete scaffolding, overhead working, and trip hazards. Warning signs can also serve as a deterrent to those who may wish to break into your premises, such as fragile roof warnings, or warnings about guard dogs.

* Flammable & Gas
Warnings signs for flammable and gas dangers are vital in any premises where your staff or customers may be in close proximity to these substances.
Whatever your risk, durable plastic yellow warning sign, from explosion risks to compressed gas, oxygen to petroleum spirit. high visibility yellow triangles with the standard black border and clear black graphics make a strong impact wherever you fix them.

* ABC Powder Extinguisher
*The ABC Powder Extinguisher Missing sign is a clever way of ensuring that an extinguisher is returned to its ideal storage place. On the top of the sign there is vital information on what the ABC extinguisher is safe for and on the bottom there is a picture of an extinguisher, with the word MISSING displayed very clearly. This should encourage people to return the extinguisher to this resting place. This ideal sign is able to do two jobs at once for you to help to keep people safe.

* ABC Powder Extinguisher The ABC Powder Extinguisher sign should be placed beside a fire extinguisher of this description. The sign provides essential information on the fact that it is good for use on fire types
A,B,C and Electrical Fires. ABC Powder : ( A ) Safe for : Wood, Paper & Textiles , ( B ) Safe for : Flammable Liquids , ( C ) Safe for :Gaseous Fires , Safe for :Live Electrical Equipment , to ensure that people only tackle the fires that are safe for this extinguisher type.

BC Powder Extinguisher : The BC Powder Extinguisher Tall sign should be placed right next to a fire extinguisher of this type. The sign will clearly indicate that this extinguisher is good for fire types B, C and electrical. It will stress that the extinguisher is not good for type A fires which involve wood, paper and textiles. ( B ) Safe for : Flammable Liquids , ( C ) Safe for :Gaseous Fires , Safe for :Live Electrical Equipment , NOT for : Wood , Paper ,& Textiles ,

 

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* Carbon Dioxide Extinguisher ( B ) Safe for : Flammable Liquids , Safe for :Live Electrical Equipment , NOT for : Wood , Paper ,& Textiles , NOT for : Flammable metal Fires ,

* BC Powder Extinguisher The BC Powder Extinguisher sign will have the relevant symbols on the left and the types of fires that the extinguisher will be safe for, on the right hand side. It is called BC because these are the categories of fire that the extinguisher is safe to use on. The sign advises of this and that the extinguisher is not good for type A fires or those that involve live electrical equipment. ( B ) Safe for : Flammable Liquids , ( C ) Safe for :Gaseous Fires , Safe for :Live Electrical Equipment , NOT for : Wood , Paper ,& Textiles ,

* Fire Hose Extinguisher The Fire Hose Extinguisher sign should be placed alongside an actual fire hose. The sign will contain the information that the hose extinguisher is good for type A fires, but not for other types. It would therefore tackle fires which involve paper, wood and textiles.

By displaying this sign, you will ensure that people are safe and only tackling the fires that extinguishers should handle. The sign can be a potential life-saver. ( A ) Safe for : Wood , Paper & Textiles , NOT for :Live Electrical Equipment , NOT for :Flammable Liquids , NOT for :Flammable metal fires ,

* Emergency Shut Down The Emergency Shut Down sign indicates a hand hovering over an appropriate button to shut a piece of machinery off in an emergency. The sign should always be used to display beside such a piece of machinery if safety would be an issue in an emergency.

* Emergency Shut Down The Emergency Shut Down sign should be placed in an area where somebody will be able to carry out this command. This sign can be a potential life-saver and so it should be displayed prominently for all to see. ( E.S.D )

* Fire Alarm Activated The Fire Alarm Activated sign will advise people that the alarm has been activated if a nearby beacon flashes. This will mean that they will not need to worry about raising the alarm themselves and can concentrate on leaving the premises via the nearest fire exit.

 

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The actual AM2 is split into 4 sections:

• Section A involves a composite installation. It is a partially completed installation which you must finish. You need to know how to terminate SWA (armoured) cable, MIMS (Mineral Insulated Metal Sheathed or simply Pyro to many) and be comfortable with simple motor circuits, although you are given a wiring diagram. Once complete a visual and a functional test needs to be carried out.
• Section B involves an inspection and test of the installation
• Section C involves safe isolation procedures and a risk assessment
• Section D is fault diagnosis and rectification
Some colleges often offer revision sessions for the AM2, although it is part of the AM2, MIMS (or pyro as often referred to) can often only be used by specialist companies or on specialist installations and is easily forgotten after being covered in college. If you get the chance, practice it.
AM2 Hints and Tips
Below are some ideas to help you pass the AM2 practical exam.
• Practice reading from a circuit diagram before you start
• Be especially comfortable with motor circuits and follow the wiring diagram given to you beforehand
• The motor can be wired in 1.5mm2 cable with the control circuit (to the remote starter
• Set the overload on the contactor
• Be comfortable with lighting circuits in singles, make sure you know how to wire a landlords override switch and a two-way & Intermediate lighting circuit override circuit
Landlords override circuit
• If the centre supply heat proof sheathing for the bulkhead light fitting, use it
• Take a padlock with you just in case and keep your tools locked
• Take a sharp knife such as an electricians knife , Stanley knives or craft knives will not be permitted
• Fully understand the correct safe isolation procedure, make sure you keep the key in your pocket or locked away
• Know how to fault find, remember, continuity and insulation resistance tests are your friends
• Practice MIMS cable but leave it until the last task on the installation.
• Make sure you do not twist the MIMS conductors in the pot when you crimp the seal in place and make sure that the seal CANNOT be pulled out (this is a fail)

• Identify all the ends using the correct colours
• Practice doing back to back bends in steel conduit, you can use a coupler but you will start losing marks
• Make sure you can find your maximum Zs values, you may be asked to perform a Zs test and compare it to the On Site Guide or an equivalent table
• Bond the gas pipe in 10.0mm2 below the tee piece
• Bond the trunking and the tray in 4.0mm2cable
• Bond the back of any metallic backboxes

AM2 changes due in 2010
Plans are currently in progress to overhaul the AM2 and potentially bring it under a QCF unit. Changes mooted are the removal of the motor control circuit completely, taking out the MIMS (MICC) installation as it is thought to be a specialist cable and taking out the conduit forming as it is thought to be a level 2 skill.

In comes a S plan heating circuit, segregated trunking and data cabling.

Other changes include the trainee having to complete a full Electrical Installation Certificate, including a Schedule of Inspection and a Schedule of Test Results instead of the old method with a couple of random boxes of information.

The AM2 is planned to be split into 4 sections, A - Installation, B - Inspection and Test, C - Fault Diagnosis and a new section D - Knowledge Assessment. The last part is planned to be a 30 question multiple choice exam with a 90% pass mark. The exam will cover health and safety, working at heights, security systems, building regulations, protective devices, hand tool and single and three phase supplies.

About AM2

Apprentices approaching the end of their training for the JIB Apprentice Training Scheme and the Electrical Installation Modern Apprenticeship, or others wishing to accredit practical experience, must take the Achievement Measurement 2 (AM2) skill test.

The Test

The AM2 skill test comprises four sections: A1 Composite Installation A1 COMPOSITE INSTALLATION

- PVC/SWA/PVC Cable 10mm² four core :

- Skill Activity, Measuring, cutting to length, installing and terminating between pre-fixed equipment.

- Metal Conduit 20mm : Measuring, cutting to length, filing and reaming, bending, threading, installing between pre-fixed equipment.

- Main Equipotential and Supplementary Bonding : Measuring, cutting to length, filing and reaming, bending, threading, installing between pre-fixed equipment.

- Main Equipotential and Supplementary Bonding : Measuring, clipping and dressing, terminating and fixing bonding clamps on service pipes etc..

- Mineral Insulated Cable (PVC sheathed) 4L 1.5mm² MICC : Measuring, cutting to length, shaping, dressing, securing, terminating, glanding; identifying conductors and connecting between pre-fixed equipment.

- Circuit Wiring - Lighting Circuit : Install PVC insulated cables for the two-way and intermediate lighting circuit. Install key operated override 'on' switch adjacent to the intermediate switch.

- Emergency Luminaire : Install FP200 2 core and earth cable between the plastic dado trunking and 20mm end box. Connections to be to the Luminaire Support Coupler (LSC).

- Industrial Socket Outlet (400V) : Install and connect the 16A triple pole and earth socket outlet to the output terminals of the 20A TP&N switchfuse.

- Three Phase Motor Circuit : Installing cables in trunking and conduit; terminating and making connections between a three phase squirrel cage motor, a motor starter, a remote start/stop/inch station and run and trip warning lights, with the aid of a wiring diagram ,
( MOTOR CONTROL CIRCUIT SCHEMATIC DIAGRAM ) ←←

- SRCD : Install cables in metal trunking to SRCD.

- Circuit Wiring - Ring Circuit : Installing cables in metal and PVC trunking and PVC conduit; terminating and making connections from the distribution board to:
* a ring circuit of 13A switch socket outlets.
* a spur to a 13A socket outlet including flexible cable to a tubular heater via a 13A plug.

The Test :

A - ASSESSMENT OF SAFE WORKING PRACTICES :
Each candidate, prior to the commencement of the Composite Installation will be required to demonstrate as assessment of Safe Working Practices.

B - COMPOSITE INSTALLATION :
This is the wiring of an installation, which includes a range of electrical circuits, each devised to assess a candidate's proficiency in particular aspects of electrical work. The electricity supply will be provided from a TN-S three phase 4 wire 400V system.

Composite Installation - Functional Operation :
After the installation has been inspected and tested each candidate will be required to demonstrate that the following final circuits operate correctly:
• Two way and intermediate switched lighting circuit
• Operate the Landlords Key Switch
• Operate the Emergency Luminaire Key Switch to effect simulated mains failure
• Ring circuit socket feeding heater
• Motor and control circuit

C - INSPECTION AND TESTING :
On completing the composite installation, each candidate will be required to carry out prescribed pre commissioning electrical installation tests in accordance with the lEE Wiring Regulations (BS 7671).

Each candidate will be supplied with necessary instructions, a copy of the current lEE On Site Guide, test results sheets and a range of instruments from which to select and prepare the one appropriate for each test.

D- SAFE ISOLATION OF SUPPLIES :
Candidates will be required, under observation, to demonstrate how to safely isolate circuits or items of equipment to ensure and verify it is safe to work on. This section of the assessment is carried out on the Fault Diagnosis Unit. Safe isolation procedure is shown in .

E - FAULT DIAGNOSIS :
Candidates will be required to diagnose and locate seven faults, introduced to the Fault Diagnosis Unit by the examiner, selected from a range of common faults , Each fault will be introduced individually to the candidates by either the examiner demonstrating the fault symptom or by the use of job cards.

F - FAULT RECTIFICATION :
Candidates will be required to diagnose, locate and rectify (where possible) five faults, which will be introduced to the Fault Diagnosis Unit. Each fault will be introduced individually to the candidates with the use of job cards

G - UNDERPINNING KNOWLEDGE ASSESSMENT :
Candidates will be required to undertake a 30 question multiple choice assessment paper. The questions will cover Health and Safety, Assessment of Safe Working Practices, Inspection and Testing, Safe Isolation and Installation Techniques. Each candidate will be supplied with a copy of BS7671, IEE on-site guide, memorandum on the Electricity at Work Regulations 1989 HS(R)25 and Electricity at Work - Safe Working Practices HS(G)85.

The sections must be completed within the specified target times. The work must comply with the
requirements of the current lEE Wiring Regulations (BS 7671) and Health and Safety Regulations.
Candidates will be permitted to refer to the current edition of the lEE Wiring Regulations (BS 7671),
lEE Guidance Note No.3 Inspection and Testing and the lEE On-Site Guide (OSG) during the tests.

 

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B – COMPOSITE INSTALLATION :

This is the wiring of an installation which includes a range of electrical circuits, each devised to assess a candidate’s proficiency in particular aspects of electrical work. The electricity supply will be provided from a TN-S three phase 4 wire 400V system.

INSTALLATION ASPECTS :
Main and Supplementary Equipotential Bonding :
* Measuring, clipping and dressing, terminating and fixing bonding clamps on service pipes etc.

Circuit Wiring - Lighting Circuit :
* Install PVC insulated cables for the two way and intermediate lighting circuit. Install key operated override 'on' switch adjacent to the intermediate switch.

Industrial Socket Outlet (400V) :
Install and connect the 16A triple pole and earth socket outlet to the output terminals of the 20A TP&N switchfuse.

Three Phase Motor Circuit :
Installing cables in trunking and conduit; terminating and making connections between a three phase squirrel cage motor, a motor starter, a remote start/stop/inch station warning indicator lights, with the aid of a wiring diagram.

Circuit Wiring – Ring Circuit :
Installing cables in metal and PVC trunking and PVC conduit; terminating and making connections from the distribution board to:
- a ring circuit of 13A switch-socket outlets.
- a one gang 13A socket outlet to supply a tubular heater via flexible cord and 13A plug.

Composite Installation – Functional Operation :
After the installation has been inspected and tested each candidate will be required to demonstrate
that the following final circuits operate correctly:
• Two-way and intermediate switched lighting circuit
• Operate the Landlords Key Switch
• Operate the Emergency Luminaire Key Switch to effect simulated mains failure
• Ring circuit socket feeding heater
• Motor and control circuit

C - INSPECTION AND TESTING :
On completing the composite installation, each candidate will be required to carry out prescribed pre-commissioning electrical installation tests in accordance with the lEE Wiring Regulations (BS 7671).

Each candidate will be supplied with necessary instructions, a copy of the current lEE OnSite Guide,
test results sheets and a range of instruments from which to select and prepare the one appropriate for each test.

D- SAFE ISOLATION OF SUPPLIES :
Candidates will be required, under observation, to demonstrate how to safely isolate circuits or items of equipment to ensure and verify it is safe to work on. This section of the assessment is carried out on the Fault Diagnosis Unit. Safe isolation procedure ,

E - FAULT DIAGNOSIS :
Candidates will be required to diagnose and locate seven faults, introduced to the Fault Diagnosis Unit by the examiner, selected from a range of common faults. Each fault will be introduced individually to the candidates by either the examiner demonstrating the fault symptom or by the use of job cards.

F - FAULT RECTIFICATION :
Candidates will be required to diagnose, locate and rectify (where possible) five faults which will be introduced to the Fault Diagnosis Unit. Each fault will be introduced individually to the candidates with the use of job cards.

G – UNDERPINNING KNOWLEDGE ASSESSMENT :
Candidates will be required to undertake a 30 question multiple choice assessment paper. The questions will cover Health and Safety, Assessment of Safe Working Practices, Inspection and Testing, Safe Isolation and Installation Techniques. Each candidate will be supplied with a copy of BS7671, IEE on-site guide, memorandum on the Electricity at Work Regulations 1989 HS(R)25 and Electricity at Work – SafeWorking Practices HS(G)85.


FAULT DIAGNOSIS UNIT ↔↔↔

Fault ,
Motor circuit ,
Circuit arrangements , Fed from way !!!! RYB3 10amp Type C, MCB ,
Fault Symptoms :
The motor control does not work correctly when operated from the remote control station ,

Replacement 2330 Units

Unit 1 - Health and Safety & Legislation
Unit 2 - Environmental & Legislation
Unit 3 - Understand procedures for organising the work environment for the installation of electrical systems and equipment in buildings and structures.
Unit 4 - Understand procedures for planning, preparing and installing electrical systems and equipment in buildings and structures
Unit 5 - Understand procedures for terminating and connecting electrical systems and equipment in buildings and structures
Unit 6 - Understand procedures for the inspection, testing and commissioning of electrical systems and equipment in buildings and structures.
Unit 7 - Understand procedures for diagnosing and correcting faults in electrical systems and equipment in buildings and structures.
Unit 8 - Understand electrical principles associated with the design, building, installation and maintenance of electrical equipment and systems

units:
Currently units 1, 2, 3 and 4 are covered in the unit 201 of the 2330. Unit 5 is very similar to the old 236 Part 2 syllabus and is close to the 2330-205 and 2330-302 in content. Unit 6 is similar to the 2330-302 and Unit 7 to the 2330-303. Unit 8 appears to be the science unit and will be close to the 2330-203 and the 2330-301 and is also very similar to the old 236 Part 2 syllabus content.

 

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You are advised that it is unlawful under the Electricity at Work Regulations 1989 to work on any electrical installation in the UK unless you are a ‘competent person’ as follows:
The Electricity at Work Regulations 1989 requires persons to be competent to prevent danger and injury. No person should be engaged in any work activity unless he or she possesses such technical knowledge or experience, or is supervised as appropriate for the work.

The Memorandum qualifies technical knowledge or experience as being:

1 Adequate knowledge or experience;
2 Adequate experience of electrical work;
3 Adequate understanding of the system being worked on and practical experience of that class of system:
4 Understanding of the hazards that may arise during the work and the precautions that should be taken;
5 Ability to recognise at all times whether it is safe for work to continue.

LEVEL 2 - UNIT 4 : Cable Selection Correction Factors

what is the correction factor for 3 circuits grouped together, installation method F (single layer multicore on a perforated vertical cable tray)? ( 0.82 ) 4C1 p-268

what is the correction factor for 4 circuits grouped together, installation method B ? ( 0.65 )

What is the installation method reference for multicore armoured cable in cable ducting in the ground? ( B )

What is the installation method reference for multicore cable installed on unperforated horizontal cable tray? ( C )

what is the correction factor for 90 degree/C, PVC thermosetting cable, in free air, in an ambient temperature of 45 degrees/C ? ( 0.87 ) 4B1 p-267

What is the installation method reference for multicore cable installed on perforated horizontal cable tray? ( E )

what is the correction factor for a BS3036 semi-enclosed fuse used for overload protection ? ( 0.725 )

what is the correction factor for a 90 degree/C PVC Thermosetting cable buried in the ground where the temperature of the ground may reach 70 degrees/C ? ( 0.53 ) 4B2 p-267

What is the installation method reference for a multicore cable installed directly in a thermally insulated wall ? ( A )

What is the installation method reference for multicore armoured cable in cable ducting in the ground? ( D )

Electrical Testing.
To achieve compliance with the legal requirements of the Electricity at Work Regulations 1989 requires proof that an electrical system is safe, which involves amongst other things, proper inspection and testing of a system by competent people and the creation and maintenance of records.

Persons to whom duties are imposed by these regulations
Status – Absolute
Duty of every employer, self employed person or employee to ensure that compliance to the Regulations is absolute, except where the duty is subject to the qualifying term “Reasonably Practicable”. The extent to which these duties are imposed on an individual is determined by the degree of “control” the individual may have. These duties are enforceable by law and failure to comply would provide for an offence that could be seen as a criminal act punishable by a fine,imprisonment or both.

All systems shall be at all times of such construction as to prevent, so far as is reasonably practicable, danger.

As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as is reasonably practicable, such danger.

Every work activity, including operation, use and maintenance of a system and work near a system, shall be carried out in such a manner as not to give rise, so far as is reasonably practicable, to danger.

Any equipment provided under these Regulations for the purpose of protecting persons at work on or near electrical equipment shall be suitable for the use for which it is provided, be maintained in a condition suitable for that use, and properly used.

No electrical equipment shall be put into use where its strength and capability may be exceeded in such a way as may give rise to danger.

Electrical equipment which may reasonably foreseable be exposed to:
• Mechanical damage.
• The effects of the weather, natural hazards, temperature/pressure.
• The effects of wet, dirty, dusty or corrosive conditions
• Any flammable or explosive substance, protected as to prevent, so far as is reasonably practicable, danger arising from such exposure.

All conductors in a system which may give rise to danger shall either be suitably covered with insulating material and as necessary protected so as to prevent, so far as is reasonably practicable, danger or have such precautions taken in respect of them (including, where appropriate, their being suitably placed) as will prevent, so far as is reasonably practicable, danger.

Precaution shall be taken, either by earthing or by other suitable means, to prevent danger arising when any conductor (other than a circuit conductor) which may reasonably foreseeably become charged as a result of either the use of a system, or a fault in a system, becomes so charged and for the purposes of ensuring compliance with this regulation, a conductor shall be regarded as earthed when it is connected to the general mass of earth by conductors of sufficient strength and current-carrying capability to discharge electrical energy to earth.

If a circuit conductor is connected to earth or to any other reference point, nothing which might reasonably be expected to give rise to danger by breaking the electrical continuity or introducing high impedance shall be placed in that conductor unless suitable precautions are taken to prevent that danger.

Where necessary to prevent danger, every joint and connection in a system shall be mechanically and electrically suitable for use.

Efficient means suitably located shall be provided for protecting from excess of current every part of a system as may be necessary to prevent danger.

Subject to paragraph (3) where necessary to prevent danger, suitable means (including where appropriate, methods of identifying circuits) shall be available for:
• Cutting off the supply of electrical energy to any electrical equipment
• The isolation of any electrical equipment
In paragraph (1) “isolation” means the disconnection and separation of the electrical equipment from every source of electrical energy in such a way that this disconnection and separation is secure.

Paragraph (1) shall not apply to electrical equipment which is itself a source of electrical energy but, in such a case as is necessary, precautions shall be taken to prevent, so far as is reasonably practicable, danger.

Adequate precautions shall be taken to prevent electrical equipment, which has been made dead in order to prevent danger while work is carried out on or near that equipment, from becoming electrically charged during that work if danger may thereby arise.

For the purpose of enabling Injury to be prevented, adequate working space, adequate means of access, and adequate lighting shall be provided at all electrical equipment on which or near which work is being done in circumstances which may give rise to danger.

No person shall be engaged in any work activity where technical knowledge or experience is necessary to prevent danger or, where appropriate, Injury, unless he possesses such knowledge or experience, or is under such degree of supervision as may be appropriate having regard to the nature of the work

If the Résistance of a 1.0mm2 conductor is 19.5mΩ/m , what would be the Résistance of ?

1) 85m of 1.0mm2 conductor :
2) 1m of 6.0mm2 conductor :
3) 25m of 4.0mm2 conductor :
4) 12m of 0.75mm2 conductor :

1) 1.0mm2 is 19.5mΩ/m , so 85m would be 19.5 x 85 ÷ 1000 = 1.65Ω
2) a 6.0mm2 conductor would have a Résistance six times less than a 1.0mm2 conductor , i.e. 19.5 ÷ 6 = 3.25mΩ
3) 25m of 4.0mm2 would be ( 19.5 ÷ 4 ) x 25 / 1000 = 0.12Ω ↔ ( 19.5 ÷ 4 = 48.75 , x 25 ÷ 1000 = 0.12Ω
4) 12m of 0.75mm2 would be 19.5mΩ/m x 1.5 x 12m = 0.351Ω

A 3kW / 230V immersion heater has ceased to work although fuses , etc , are all intact , a test using a low résistance ohmmeter should reveal
The heaters résistance , which can be determined from ,

P = V2 / R
So , R = V2 / P

= 230 x 230 = 52.900 ÷ 3000 = 17.6Ω

This can be compared with the manufacturers intended résistance ,
This would show that the element is not broken and further investigation should take place ( probably a fault thermostat )

 

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Steel Armoured Cable is protected by a sheath of galvanised steel. This makes it suitable for direct burial, cable ducting or it can be surfaced mounted without any further protection. It can be used for indoors and outdoors.
Steel Armoured Cable (SWA) Cores Colours

2 core = Brown/Blue
3 core = Brown/Black/Grey
4 core = Blue/Brown/Black/Grey
5 core = Green-Yellow/ Blue/Brown/Black/Grey
Alternative core colour - Black numbered

Blowing a fuse with an earth fault.

When there is an earth fault we not only want the fuse to blow but we also want it to blow quickly and it has been calculated to get a 13 amp fuse to blow in 0.4 seconds it will take 95 amp. In order for 95 amp to flow using ohm's law (230/95) we know we know the resistance needs to be 2.42Ω this is referred to as the earth loop impedance.

So what is the earth for ?
The earth ensures in the event of a fault the supply is automatically disconnected. There are two main ways of doing that the first is to open an over current device i.e. blow a fuse and the second is by measuring power in and power out and if they are not equal it is assumed the difference is going to earth and it operates what is called a residual current device RCD in both cases the supply is automatically disconnected.

Definitions
.
Earth fault current. An overcurrent resulting from a fault of negligible impedance between a line conductor and an exposed-conductive-part or a protective conductor. This is a direct short to earth and the maximum that can flow.

Earth leakage current also called Prospective conductor current. Electric current appearing in a protective conductor, such as leakage current or electric current resulting from an insulation fault. In this case not necessary a short circuit maybe only a few milliamp.


Circuit protective conductor (cpc). A protective conductor connecting exposed-conductive-parts of equipment to the main earthing terminal.

Main earthing terminal. The terminal or bar provided for the connection of protective e conductors, including protective bonding conductors, and conductors for functional earthing, if any. to the means of earthing.

Exposed-conductive-part. Conductive part of equipment which can be touched and which is not normally live, but which can become live when basic insulation fails. For example the metal of an electric towel rail.

Extraneous-conductive-part. A conductive part liable to introduce a potential, generally Earth potential, and not forming part of the electrical installation i.e. the soil pipe I talked about.

Is low voltage the same as low energy ?
No! It's the watts that count, not the volts.
There is a common misconception that low voltage lighting systems are the same thing in terms of energy efficiency as low energy lighting systems. On this page we will try to explain why this is.
Measuring energy

Energy is measured in watts - your electricity bill probably shows how many kilowatts you have used. A kilowatt is 1000 watts.

Therefore, if you can produce a lot of light while using a small amount of watts you have a low energy light, and a cheaper electricity bill.

You probably know that low energy light bulbs have a small wattage rating and are often compared to an equivalent wattage. You might see that an 11w low energy bulb is the equivalent of a 60w normal bulb. This is only comparing the amount of light that is produced, it has nothing to do with the amount of energy consumed.
Volts, amps and watts
To show that a low voltage light is not a low energy light, we will compare these three lights:
• 50w low voltage spot light
• 50w mains voltage spot light
• 9w low energy spot light.
All three examples will produce about the same amount of light, but only one will cost less to run.
You might remember from your school days that watts = volts x amps. Once we know this we can easily show that the maths confirms the number of watts used by each of the three example light:

Volts (The electric supply connected to the light) Amps ( watts divided by volts) Watts (as described by the product)
………………………………………………. Volts ………………… Amps ………………. Watts 50w low voltage spot light …….12 …………………… 4.17 ……………………. 50 50w mains voltage spot light ….230 ………………….. 0.21 …………………… 50 9w low energy spot light ……….. 230 ………………….. 0.03 ………………….. 9

As you can see - the 230v 50w bulb uses exactly the same amount of watts (power) as the 12v 50w bulb.
But doesn't it use less power because it's running at 12 volts ?

No - watts are watts. It doesn't matter what the voltage is. We can show this more clearly by explaining about transformers:
Transformers
Low energy lighting such as the 9w bulb in our example will generally run at the full mains voltage, without requiring any change in the voltage.
Most low voltage lighting runs at 12 volts so unless you're running it from a battery (e.g in your car) there has to be a transformer to reduce the mains electricity supply from 230 volts to 12 volts. Some light fittings have a transformer built into them, and sometimes a separate transformer is required.

Transforming volts and amps
When a transformer transforms a voltage it also transforms the available amount of amps - In the table above you can see that the 12v light uses a lot more amps then the mains voltage lights.
The available amps are transformed by the same ratio as volts but in the opposite direction, so if the voltage is reduced by 20 times (230v to 12v) the amps are increased by 20 times (0.21 to 4.2).
In our above example the voltage has been reduced by 20 times, so the amps have increased by 20 times, but the wattage is the same.

Additionally because the transformer efficiency will not be 100% (some energy is lost in the transformation) the 12v bulb might even more use more power than the 230v one, as the transformer will be 'using' some as well as the light.

Is low voltage the same as low energy ?
No - it's the watts that count, not the volts.

 

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One thing to always remember is that nothing is 100% foolproof. All of these tests are those used by the IET as the best tests available to ensure maximum safety.

Tests done before the power is turned on, these establish that nothing will go bang and that all protective devices (circuit breakers and RCD) will work from the moment the power is turned on.

Continuity of protective conductors - Here Continuity really just means that the earth cabling is continuous and has no breaks.
This involves checking that all 'earth' connections are sound so that if a fault develops the voltage will go to earth.
Why this is important is that if an appliance is faulty, i.e. loose wire in a washing machine touches the casing, and there is no path to earth the circuit breaker will not work. So the machine stays live until there is a path to earth, such as someone touching it.
If there is a good earth connection then this will cut the power immediately before any harm can be done.

Continuity of final circuit conductors - This is to ensure that the 'live' and 'neutral' are the same in each socket and appliance on a circuit.
It is important that these are not mixed up causing someone to think the cable is the neutral when it is actually live.
Although people will tell you this doesn't matter in France it does. It is less important as French circuit breakers cut the power to both live and neutral, whereas in the UK they only cut power to the live side.

Insulation Resistance - Believe it or not power can 'leak' through insulation on cables, this tests for any leakage.
The test is done by applying a high voltage through the cables and noting the resistance. In new cables this is usually very high but if old or damaged it can give a low reading.
All readings should be high but if not this indicates possible damage to the insulation or even such things as a faulty or damaged socket.
Best to find these before the power is switched on, as you can imagine.

Polarity - Tests that live is live and neutral is neutral.
This especially applies to appliances such as washing machines, also to fluorescent lighting and especially screw in type lamps.


So - At this point when we turn on the power there should be no surprises.

Tests once the power has been turned on. Now we know nothing will go bang and that if there are any problems people will be protected we can turn on the power. Then we can use the power now in the circuit to do tests to confirm the test results done with the power off.

Earth electrode resistance - This only applies if you have an earth rod fitted.
It is possible to measure this before power is turned on using special test equipment.

Earth fault loop impedance - Sounds very grand doesn't it, basically it means measuring the maximum true resistance for a circuit.
This is important as if it is too high either the RCD will not work in the required time, or not at all.
Circuit breakers will also fail to work if this resistance is too high.
This requires a specialised meter to do this, a cheap one from a DIY store will not give this reading as accurately as it needs to be done.

Prospective fault current - Based on the Earth fault loop impedance really. This shows what the current will be if you do have a fault such as the live cable shorting out. This can be hundreds of Amps so this is where the Circuit Breaker comes in as it will cut the power before this massive current can do any damage.
You need to know this in order to ensure that all circuit breakers etc. can withstand this amount of current without damage.
Most can but best to be sure, the lower the loop impedance the higher the fault current.
Loop impedance is usually high where an earth rod is used, but will be low where a supplier's earth connection is used. As a general rule the closer to the supply transformer then the lower the resistance is, so the higher the fault current.

Functional tests - Just testing that all the items work. Lights come on as expected, sockets all work etc.
Simply testing the switches to see that all works as it should. Switching on high load appliances to see that they can all be put on at the same time and so forth.

Conductor Materials :

The Primary Materials in use today are Copper & Aluminium ,
These two Materials are used because they are reasonable in cost and are good Electrical Conductors ,
Good Conductors ;

Silver :
* best Conductor ,
* used for contacts ,
* plated onto some Conductors ,
Copper :
* good Conductor ,
* most widely used ,
Aluminium :
* not as good as Copper ,
* strong , light , and cheap ,
* used for transmission Conductors ,
* used for power distribution ,
Gold :
* almost as good as Copper ,
* extremely résistance to corrosion ,
* too expensive for general usage ,
* used primarily for contacts and terminals on printed circuit boards ,
Fair Conductors :
Brass , Zinc , Iron , and Nickel
Tungsten ( used for filaments )
Nichrome ( used for heating elements )
Mercury ( used for thermostats’ and switches )
Copper : Copper is most important and commonly of all conductor materials . copper is used because it possesses several

Desirable characteristics ,
* Copper is highly conductive ( both thermally & electrically ) it is second only to silver and gold in conductivity ,
* Copper is plentiful and relatively inexpensive when compared to silver & gold ,
* Copper is both ductile and malleable . these properties make it ideal for use as a conductor ,
* Because it is resistant to both corrosion and fatigue , copper may be used in a variety of industrial and commercial environments ,
Aluminium , Aluminium is the second most popular material used in fabrication of electrical conductors , it is cheaper and lighter
Than copper and has almost as good thermal and electrical conductivity , unlike copper , aluminium does not possess it the tensile
Strength . it transmission lines , aluminium is reinforced with steel to give it the tensile Strength required , aluminium possesses several other characteristics ,
* Aluminium expands and contracts on copper terminals , causing high résistance and resultant heat , High résistance builds up because
The copper and aluminium have different thermal coefficients ; therefore , the terminals loosen when aluminium is used with copper ,
* Aluminium corrodes when connected to copper conductors because of galvanic chemical action caused by the reaction of the two
Dissimilar metals , No-oxide chemical compounds must be used to prevent this reaction ,
* Aluminium is used in power systems , depending upon the design and code requirements ,
* Aluminium is used in transmission , shipyard , building ,
* Aluminium does not conduct as well as copper and , therefore , must have a slightly larger cross-sectional area for the same ampacity
In spite of this , Aluminium conductors are generally lighter and less expensive than copper conductors of the same ampacity ,

 

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method when installing cable on insulation ?

Reference methods 100 and 101 refer to twin & earth (T/E) cable installed within various thickness of insulation. What reference method should I use when cable is installed on top of any insulation ?

Regulation 523.7 of BS-7671 requires that, where a cable is to be run in a space to which thermal insulation is likely to be provided, the cable is - wherever practicable - to be fixed in a position where it will not be covered by the thermal insulation.

the cable would appear to be in contact with thermal insulation on one side only. Therefore, if there is free air on the remaining sides of the cable, reference method 'C' for either Table 4D2A or Table 4D5 would be appropriate.

BS5803-5:1985
Thermal insulation for use in pitched roof spaces in dwellings. Specification for installation of man-made mineral fibre and cellulose fibre insulation

Thermal insulating materials, Roof spaces, Pitched roofs, Domestic facilities, Man-made fibres, Mineral fibres, Cellulose, Fibres, Installation, Sheet materials, Pellets, Beads, Particulate materials, Thermal insulation, Water storage cisterns, Pipes, Ven
Cross references :
BS 874, BS 3533, BS 3589, BS 5250, BS 5422, BS 5803art 1, BS 5803art 2, BS 5803art 3, BS 7671, PD 6501art 1

Loft Insulating Materials
Mineral fibre or fibreglass matting is usually available in rolls 400mm (16in) wide. Thicknesses range from 100mm (4 in) to 200mm (8 in). In the UK, the total thickness of insulation should be at least 200mm (8in), the thinner insulation material available allow for old, thinner loft insulation to be overlaid to achieve the 200mm. Roll insulation

Sheep’s Wool insulation is a general purpose natural wool fibre product designed for use in loft, rafter, internal wall and inter-floor applications. It is specifically constructed to match and surpass the Part L Building Standards with reference to Thermal, Fire, Mould Resistance and Structural performance.

 

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COLD BENDING 20-25MM CONDUIT

This may be carried out on all conduit sizes up to25mm in diameter using the correct size and gauge of bending spring. It should be noted that the heavy gauge spring is colour banded green and the light gauge spring colour banded white near the tip of the spring. These springs are not interchangeable under any circumstances. Make sure they are not damaged in any way as this can cause the conduit to kink and fracture making removal of the spring difficult.(In cold weather the Conduit should be warmed by rubbing with a rag or some other suitable means before bending.)

To bend the conduit insert the spring to the desired position, grip the conduit on either side of the
bend and bring slowly together to form the bend. The bend should be made more acute than necessary because of the tendency of the PVC-U to ‘recover’ after bending. To remove the spring twist in an anti-clockwise direction which will reduce its in an anti-clockwise direction which will reduce its diameter. At the same time turn the conduit in a
clockwise direction gently pulling the spring and conduit apart. If the spring fails to release during this operation do not pull too hard otherwise damage to the spring may occur. Repeat the removal procedure turning the spring again in an
anti-clockwise direction and rotating the conduit clockwise slowly pulling them apart. The conduit
should then be fastened into position to prevent further ‘recovering’ of the bend.

HOT BENDING

This should be carried out on all conduit above25mm diameter using the correct size and gauge of
bending spring. Insert the bending spring into the conduit as previously described, gently heating the
conduit with a hot air torch, hot water or by other suitable means, with care being taken to avoid the
direct application of a flame to the conduit. When the conduit is in a pliable state, slowly bend around a suitable former, holding in position for about one minute until set when the bending spring may then be removed by twisting in an anticlockwise direction and gently withdrawing from the conduit. If the conduit is bent too fast or, particularly in the
case of light gauge across the knee, there is a risk of damage to both the conduit and spring. Similarly
once the bend has been made it should not be forced backwards but allowed to recover naturally.

JOINTS AND COUPLERS

To accommodate for thermal movement due to temperature change (Materials Data) on surface installations, it is recommended that expansion
couplings be used at a maximum distance of 6m intervals. Where high ambient temperatures or frequent variations in temperature are likely to occur this distance should be reduced. Expansion couplers are installed with the →→ short side coated with solvent cement ←← and the coupler pushed firmly over the conduit down to the shoulder. The slip side coated inside with lubricant sealant receives the conduit to a midpoint to the nib. This will then permit expansion or contraction providing the conduit is free to move in the saddles.

Conduit fittings are installed in the system using solvent cement (MSC20) for permanent installations and lubricant sealant (MSC1) where the installation is subject to frequent changes.

Straight runs exceeding 3 metres, or runs of any
length incorporating bends or sets. The term ‘bend’ signifies a British Standard 90º bend and one double set is equivalent to one bend.

Conduit / Following cable factors :

O.S.G ( table 5C ) 16 for 1mm2 , 30 for 2.5mm2 & 58 for 6mm2
Cf : ( 8 x 16 ) + ( 4 x 30 ) + ( 2 x 58 ) = 128 + 120 + 116 = 364

the term “ bend “ means a right angle bend or left angle or double set ,

O.S.G ( table 5D ) gives a conduit factor for 20mm conduit 6m long with double set as 233 ,
Which is less than 364 and thus to small . The next size has a conduit factor of 422 which will be acceptable since it is larger than 364 .

The correct conduit size is 25mm diameter ,

O.S.G ( table 5D ) 10m long Straight 25mm conduit has a factor of 442 . This is too small , so the next size , with a factor of 783 must be used ,
The correct conduit size is 32mm diameter ,

Example :
1.5mm2 Straight length of conduit from a Consumers Unit encloses ten 1.5mm2 & four 2.5mm2 Solid ↔ Conductor P.v.c
Insulated cables , Calculate a suitable Conduit size ,

From O.S.G ( table 5A ) which is for short straight runs of conduit ) total cable factor will be :
1.5mm2 ↔ 10 x 27 + 2.5mm2 ↔ 4 x 39 = 426

From O.S.G ( table 5B ) 20mm diameter conduit with a factor of 460 will be necessary ,

Example :

A length of trunking is to carry eighteen 10mm2 , sixteen 6mm2 , twelve 4mm2 , and ten 2.5mm2 Stranded single P.v.c
Insulated cables , Calculate a suitable trunking size , O.S.G ( table 5E )
18 x 10mm2 at 36.3 = 18 x 36.3 = 653.4
16 x 6mm2 at 22.9 = 16 x 22.9 = 366.4
12 x 4mm2 at 15.2 =12 x 15.2 = 182.4
10 x 2.5mm2 at 11.4 = 10 x 11.4 = 114.0
Total cable factor = 1316.2

From the trunking factor O.S.G ( table 5F )
Two stranded trunking sizes have factors slightly greater than the cable factor , and either could be used ,
They are ( 75mm x 50mm at 1555 ) & ( 100mm x 38mm at 1542 )

CAPACITY EXAMPLE : 5C

Number of cables for a 3.0 metre run with three bends
CONDUIT 20mm dia.
CABLE SOLID 2.5mm2 ( 3 qty )
CABLE STRANDED 4.0mm2 (2 qty )
Term total – ( 30+30+30 )+( 43+43 ) = 176

Note-: It is recommended that a 32 TPI hacksaw blade be used for cutting steel trunking.

Earthing of Steel Trunking

A trunking installation must be earthed. Earth continuity is ensured by the proper tightening of all bolts used throughout the system. Some manufactures recommend that earth continuity be completed by fixing a copper or aluminium strap across all joints. It is more important that all the bolts involved in the system are tightened. It is not unusual to find that copper or aluminium straps are used, but are left loose, resulting in poor earth continuity.

Eddy Currents in Steel Conduit

Metal conduits in which a.c. circuit wiring is installed MUST contain all the current carrying conductors of each circuit in the same conduit, to eliminate the possibility of induced eddy currents. Eddy currents could result in the metal conduit and cables becoming hot.

Some Advantages of Steel Conduit
• Affords cables good mechanical protection
• Permits easy rewiring
• Minimises fire risks.
• Can be utilized as the Circuit Protective Conductor. ( CPC )

Cable Capacity of Steel Conduit ( Space Factor )

Having determined the correct number and cross-sectional area of cables for a given load it is necessary to select the size of conduit that will accomodate them.
If a greater number of cables are installed in the conduit, over-heating, insulation damage and fire may result. As a general rule the number of cables drawn into a conduit should not be such as to cause damage to either the cables or the conduit during the installation.

Termination of Steel Conduit to Enclosures

Two methods of terminating steel conduit are commonly used.
• The coupling and male bush method, (Usually used and preferred)
• The locknut and female bush method, (Used where space is tight)

Jointing Steel Conduit

Where two lengths of conduit are to be joined a plain coupling is used. To ensure good electrical continuity and maximum mechanical strength the tube ends must tighten inside the coupling (Max gap 2 mm) Care must be exercised to do this without leaving threads outside the coupling.
Where neither tube can be turned it is necessary to resort to the technique known as the “running coupling” , After tightening up the lockring the exposed thread must be painted to prevent corrosion.
Expansion of PVC Conduit
Expansion couplings should be used for surface installations at a recommended maximum of 4 metre intervals.
Where frequent variations in ambient temperature are likely to occur this distance must be greatly reduced.

Advantages of PVC Conduit
• Lightweight and easy to handle
• Easy to cut and deburr
• Simple to form and bend
• Does not require painting
• Minimal condensation due to low thermal conductivity in wall of conduit.
• Speed of installation
• Excellent electrical and fire resistant properties

Disadvantages of PVC Conduit

• Care must be taken when glueing joints to avoid forming a barrier across the inside of the conduit.
• If insufficent adhesive is used the joints may not be waterproof.
• PVC expands about 5 times as much as steel and this expansion must be allowed for.
• PVC does not offer the same level of mechanical protection as steel.
• A separate Circuit Protective Conductor must be run inside the conduit.

 

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Ways of assessing Knowledge Evidence:
Questioning
Both verbal and written questioning gives the teacher/tutor the opportunity to gauge the learner’s understanding and allows them to demonstrate their underpinning knowledge. Questioning can be done during feedback sessions and can be used to check whether learners can understand their mistakes when errors are pointed out or to explore in greater depth a situation which has arisen.
• Oral questions
Oral questioning is used to check a learner’s underpinning knowledge of the subject. The learner can be asked questions about a subject which has just taken place or more general questions to check on their knowledge about other topics in which they are involved. If the answers to the oral questioning are to provide final portfolio evidence, concise but clear notes should be made at the time by the assessor. These notes should be signed and dated by the learner and by the assessor for verification purposes.
• Written questions
Written questions could be set in the contexts of task sheets, short tests or homework and can take several forms from short to extended answers. They are a valuable assessment tool to check a learner’s underpinning knowledge as it gives the teacher/tutor the opportunity to ask more searching questions and the learner the opportunity to think about their answers and to do some research if necessary. Once the answers have been assessed, the learner and their assessor have some tangible evidence which can form a basis for discussion and there will be a record of the answers in the portfolio.
• Pre-set questions
These could be set by the assessor as homework, or given under test conditions. In some circumstances, they could also be examination questions set by the Awarding Body. In this case, all learners doing the qualification are being given the same sets of questions in the interests of fairness and standardising assessment practices. A bank of questions may be produced which are used for assessment purposes by all assessors for a standard approach.
• Assessor devised questions
These would generally be set by the teacher/tutor. Some sets of questions may need to be specifically devised to test certain required skills. Other questions can be devised to be used as a learning tool for the learner and an assessment tool for the teacher/tutor. They are valuable in that they allow the teacher/tutor to be responsive to the particular conditions under which the learner is working.

An ammeter inserted in the circuit will record a PLUS and MINUS READING. Which means the current is flowing in the opposite direction.

In most cases many cycles of the waveform occur in one second and the number of
cycles which occur per second is known as the FREQUENCY – Symbol ( f ). Frequency is measured in HERTZ - (Hz).

Time ( mS ) : there are five cycles occurring in one second and hence :- Frequency ( f ) = 5 Hz
Relationship between frequency and period (time):-
( a ) f = 1 – T Hz or ( b ) T – 1 – f sec

Where T is the PERIOD (i.e. the time taken to complete one waveform )

Examples :
1. A waveform has a frequency of 5 Hz, calculate the period of the waveform.
T = 1 – f = 1 – 5 = 0.2 sec
(This means 1 waveform will be traced every 0.2 seconds)
2. If the period of an AC waveform is 5milli seconds , find the frequency
5 milli seconds = 0.0005 seconds
f = 1 – T = 1 ÷ 0.0005 = 200Hz

Exercise :
1. Given the following frequencies, calculate the period of the waveform.
(a) f = 100Hz
(b) f = 5Hz
(c) f = 20Hz
(d) f = 100Hz
(e) f = 1Hz

2. Given the following periods of each cycle calculate the frequency of the waveforms.
(a) T = 0.05 seconds
(b) T = 2 seconds
(c) T = 25 milliseconds
(d) T = 125 milliseconds
(e) T = 5 milliseconds

Power Dissipation :

All components have resistance so when a current flows through them power is dissipated in most cases in the form of heat. It is something to be aware of in the selection of components to be used in a circuit that the power ratings are not exceeded, examples are bulbs and resistors.

Example 1
Find the power dissipated by the bulb ( Resistance of bulb = 100 ohms )
To find the power dissipated in the bulb which has a resistance of 100Ω
If the formula Power = I x V watts is to be used the following data must be known: current flowing through the bulb and voltage across the bulb.
As the 200 Ohms resistor and the lamp are in series then :
R t = 200 + 100 = 300Ω
So now having one voltage and one resistance the current flowing in the circuit can be calculated :
I = V – Rt = 9v ÷ 300 = 0.03 Amps
The voltage across the bulb can be found:
V (bulb) = I x R where R = the resistance bulb and I is the current
Vd = 0.03 x 100 = 3volts
We now have values for both the current through the bulb and the voltage across it.
P = I x V = 0 .03 x 3 = 0 .09W or 90mW.
The power could also be calculated using the formula : Power = V2 – R = 9 ÷ 100 = 0.09 watts

Example 2
In the circuit shown calculate the power dissipated in the 3Ω resistor.
18V / R1 = 4Ω R2 = 6Ω R3 = 3Ω
The first step is to find the total résistance of the circuit.
R2 and R3 are in parallel and this parallel arrangement is in series with R1
To calculate the parallel pair R2 // R3 ( let equivalent resistance = Rv )
Rv = R2 x R3 = 6 x 3 = 18
…….R2 + R3 ….. 6 + 3 ….. 9 = 2 Ω

Circuit now reads R1 and R2 in series.
18V / R1 = 4Ω Rv = 2Ω : R total = R1 + Rv = 4 + 2 = 6Ω

From having one voltage and one resistance the current flowing in the circuit can be found:
18V R total = 6Ω ( I = V – R total = 18 ÷ 6 = 3 Amps

Knowing there is 3Amps flowing in the circuit we can now calculate the voltage across the two resistors in parallel. Remember that their effective resistance is 2Ω

Voltage across parallel block: I x Rv = 2 x 3 = 6volts 18V R1 =4 Ω R2 = 6 Ω R3 = 3Ω V = 6V : Voltage = 6V Résistance = 3 Ω Power dissipated by the resistor : Power = V2 – R = 6 x 6 – 3 = 12 Watts

Exercises :
(a) In the circuit shown the motor has an internal resistance of 10Ω Find the power developed by the motor. ( 20V )
(b) Calculate the power dissipated in the 12Ω resistor. ( 54V / 6Ω 120Ω )
(c) The bulb shown has a filament resistance of 12 ohms. Calculate the output power. ( 45V / 6Ω 120Ω ulb )
(d) In the circuit shown all the bulbs have a resistance of 10Ω. Find the output power B3 : ( 30V / B1 / B2 / B3 )

 

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Ohms Law :

Power = V2 – R or R x I2 or V x I
Voltage = P – I or R x I or √ P x R
Resistance = V – I or V2 – P or P – I2
Current = P – V or V – R or √ P – R

1a) Three resistors are connected in series to a 240 V power supply. One of the resistors is rated at 10 Ω, one at 15 Ω, and the third is unknown. If the current in the circuit is measured to be 4 A, what is the total resistance of the circuit ? ( 60 Ω )

1b) What is the rating of the unknown resistor ? ( 35 Ω )

1c) What is the voltage drop across the unknown resistor ? ( 140 V )


2 ) Four resistors are hooked up in series to unknown power supply. The resistors are rated as follows; 5 Ω, 10 Ω, 20 Ω, and 25 Ω. If the voltage drop across the 10 Ω resistor is measured to be 60 V, what is the rating of the power supply ? ( hint: first find the current in the circuit )( 360 V )

V . R1.R2.R3 ,

V/1 . 120 V. R1 5 Ω . I1 24 A
V/2 . 120 V. R2 10 Ω . I2 12 A
V/3. 120 V. R3 25 Ω . I3 4. 8 A
V total 120V . R total 2.94 Ω . I total 40.8 A
Fill in the rest of the blanks if V total = 120V, R1 = 5 Ω, R2 = 10 Ω, and R3 = 25 Ω

* Ohm’s Law V I R =
(Voltage drop equals current times resistance.)
This is the main equation for electric circuits but it is often misused. In order to
calculate the voltage drop across a light bulb use the formula: V light bulb = I light bulb R light bulb
For the total current flowing out of the power source, you need the total resistance of the circuit and the total
Current : V . total = I total , R total ,

Power is the rate that energy is released. The units for power are Watts (W), which
equal Joules per second [W] = [J]/. Therefore, a 60 W light bulb releases 60 Joules energy every second

The equations used to calculate the power dissipated in a circuit is P. I V =

As with Ohm’s Law,
one must be careful not to mix apples with oranges. If you want the power of the entire circuit, then you multiply the total voltage of the power source by the total current coming out of the power source. If you want the power dissipated (i.e. released) by a light bulb, then you multiply
the voltage drop across the light bulb by the current going through that light bulb

 

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Why measure earth loop impedance ?

Earth loop impedance testing is essential since if a live conductor is accidentally connected to an earth conductor in a faulty appliance or circuit, the resulting short-circuit current to earth can easily be high enough to cause electric shock or generate enough heat to start a fire. Normally, the fuse will blow or another circuit protection device will trip, but a
situation may arise where the actual short-circuit current in a faulty installation is of insufficient level and the protection device would thus take too long to activate. The delay can be disastrous for life and property. It is therefore necessary to know if the impedance of the path that any fault current would take is low enough to allow sufficient current to flow in the event of a fault and that any installed protective device will operate within a safe time limit.

Verifying protection by automatic supply disconnection :

fault loop testing falls under the category of ‘Verifying protection by automatic supply disconnection’.
This covers verification of the effectiveness of protective measures, and the test methods applied depend on the type of system. TT systems, for example, require measurement of the earth electrode resistance for exposed conductive- parts of the installation,
whereas IT systems use calculation or measurement of the first fault current. This application note looks specifically at TN systems, which require measurement of the fault loop impedance and verification of the characteristics of the associated protective device ( i.e. visual inspection of the nominal current setting for circuit-breakers, the current ratings and blow characteristics
for fuses and the correct functioning of RCDs ).

The earth loop impedance of each individual circuit from the point of use back to the incoming supply connection point should be measured.

A separate measurement of the external loop impedance of the installation can also be made at the incoming supply point or main distribution panel and this value will form part of the overall loop impedance from any part of the final circuit installation. Knowing the earth loop impedance, it is possible to calculate the value of the prospective fault current (PFC) at any point in an installation and to ensure that all installed protective devices are of an adequate rating to clear the potential fault current level.

Measuring earth loop impedance :

Since the AC impedance of a circuit may be different from its DC resistance particularly for circuits rated at over
100 A – the fault loop impedance is measured using the same frequency as the nominal mains frequency (50 Hz).
The earth loop impedance test measures the resistance of the path that a fault current would take between line and protective earth. This must be low enough to allow sufficient current to flow to trip a circuit protection device such as a fuse or miniature circuit breaker.

testers can be
used to carry out the test at a distribution board using the three separate test leads supplied, and at appliance
outlets using a dedicated lead fitted with a mains plug. A plug of the appropriate national standard is also

Determining the PFC is important to ensure that the capability of fuses and over-current circuit breakers are not exceeded.

Interpreting results and taking remedial action :

Remember that it is not sufficient just to carry out tests and record the results. Knowledge of Regulations– and of how to interpret results – is also required to ensure the installation’s safety characteristics are within the prescribed limits. An excessive earth loop impedance value should, for example, prompt an investigation into its cause. Remedial be carried out, and the installation action should then retested.

Multifunction Installation Testers have a loop impedance test function in addition to being able to measure
prospective short circuit current (PSC) and fault current (PFC).

Proper use of clamp meters in commercial and residential environments ?

Clamp meters in residential applications;

For residential electricians, clamps are a necessity to measure loads on individual branch circuits at the distribution panel.
While a spot check of current is often sufficient, sometimes it doesn’t provide the full picture as loads are switching on and off, going through cycles, etc. Voltage should be stable in an electrical system, but current can be very dynamic. peak or worst-case loading on To check the a circuit, use a clamp with a min/max function which is designed to catch high currents that exist for longer than 100 ms, or about eight cycles. These currents lead to intermittent overload conditions which can cause nuisance tripping of circuit breakers.
Take measurements on the load side of the circuit breaker load side of the circuit breaker or fuse. The breaker will open the circuit in the event of an accidental short circuit. This is especially important with any kind of direct-contact voltage measurement. Even though
clamp jaws are insulated and therefore have a level of protection that doesn’t exist with direct-contact voltage measurement, it’s still a good idea to be cautious. A common problem in residential electrical work is mapping outlets to breakers.
A clamp can be useful in identifying which circuit a particular outlet is on. First take a baseline reading, at the distribution panel, of the existing current on the circuit. Then put the clamp in min/max mode. Go to the outlet in question, plug in a load—a hair dryer is ideal—and turn it on for a second or two. Check the clamp to see if the max current reading has changed. A hair dryer will typically draw 5 A, so there should be a noticeable difference. If the reading is the same, you’ve got the wrong breaker.

Clamp meters in commercial environments :

Clamp meters are used at the panelboard to measure circuit loading on feeders as well as on branch circuits. Measurements on branch circuits should always be made at the load side of the breaker or fuse.
• Feeder cables should be checked for balance as well as loading: current on all three phases should be more
or less the same, to minimize the return current on the neutral.
• The neutral should also be checked for overloading. With harmonic loads, it’s possible for the neutral to be
carrying more current than a feeder—even if the feeders are balanced.
• Each branch circuit should also be checked for possible overloading.
• Finally the earth circuit should be checked. Ideally there should be no current on the earth,

Testing for leakage currents :

To check if there is leakage current on a branch circuit, put both the live and neutral wires in the jaws of the clamp. Any
current that is measured is leakage current, i.e., current returning on the earth circuit The supply and return currents
generate opposing magnetic fields. The currents should be equal (and opposite) and the opposing fields should cancel
each other out. If they don’t, that means that some current, called leakage current, is returning on another path, and
the only other available path is the earth. If you do detect a net current between the supply and return, consider the nature of the load and the circuit. A mis-wired circuit can have up to half of the total load current straying through the earth system. If the measured current is very high, you probably have a wiring problem. Leakage current may also be caused by leaky loads or poor insulation. Motors with worn windings or moisture in fixtures are common culprits. If you
suspect excessive leakage, a de-energized test using a megohm -meter will help evaluate the integrity of the circuit’s insulation and help identity if and where a problem exists.

Continuity :

Testing the continuity of protective conductors is normally carried out with an instrument being able to generate a no-load voltage in the
range 4 to 24 V (DC or AC) with a minimum current of 0.2 A. The most common continuity test is measuring the resistance of protective
conductors, which involves first confirming the continuity of all protective conductors in the installation, and then testing the main and supplementary equipotential bonding conductors. All circuit conductors in the final circuit are also tested. ( 612.2.1 ) ↔

As Continuity Testing Measures very Low Résistances ,
the resistance of the test leads must be compensated for. a time-saving Auto-Null feature that, by simply touching the test leads together and
pressing the zero button, measures and stores the test lead resistance,

 

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Verifying protection by automatic supply disconnection :

Verification of the effectiveness of the measures for protection against indirect contact by automatic disconnection of supply depends on
the type of system. In summary, it is as follows:

• For TN systems: measurement of the fault loop impedance; and verification of the characteristics of the associated protective device
the associated protective device nominal current setting for circuit breakers, the current ratings for fuses and testing RCDs).

• For TT systems: measurement of the earth electrode resistance for exposed-conductive-parts of the installation; and verification of the
characteristics of the associated protective device (i.e. RCDs by visual inspection and by test).

• For IT systems: Calculation or measurement of the fault current.

Measurement of fault loop impedance :

Measurement of the fault loop impedance is carried out using the same frequency as the nominal frequency of the circuit (50 Hz). The
earth-loop impedance test measures the resistance of the path that a fault current would take between line and protective earth, which must be low
enough to allow sufficient current to flow to trip a circuit protection device such as a MCB (Miniature Circuit Breaker).

Functional test :

All assemblies, such as switchgear and control gear assemblies, drives, controls and interlocks, should be functionally tested to show that they
are properly mounted, adjusted and installed in accordance with the relevant requirements of the standard. Protective devices must be
functionally tested to check whether they are properly installed and adjusted.

Polarity test :

Where regulations forbid the installation of single-pole switching devices in the neutral conductor, a test of polarity must be made to
verify that all such devices are connected in the phase only. Incorrect polarity results in parts of an installation remaining connected
to a live phase conductor even when a single-pole switch is off, or an over-current protection device has tripped.

 

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Where metal conduit is used as a protective conductor, its cross-sectional area shall be determined either by application of the formula of 543.1.4 , or Table 54.7

* AC motor :
A type of electric motor that runs on alternating current. AC motors are more commonly used in industry than DC motors but do not operate well at low speeds.
* alternating current :
Current that regularly reverses the direction of its flow in a repeating, cyclical pattern.
* armature :
The part of a motor or generator in which a current is induced by a magnetic field. The armature usually consists of a series of coils or groups of insulated conductors surrounding a core of iron.
* bearing :
A friction-reducing device that allows one moving part to glide past or rotate within another moving part.
* brush :
A device found inside a generator that is used only in pairs to transfer power from a rotating object. Brushes rest on the commutator of a DC motor.
* capacitor :
An electrical device that stores energy and releases it when needed. A capacitor gives a single-phase motor more torque but has a limited life.
* capacitor motor :
A single-phase motor with a running winding, starting winding, and a capacitor. Capacitor motors have more torque than other single-phase motors.
* capacitor start-and-run motor :
A type of capacitor motor that uses two capacitors, one for starting the motor, and one that remains in the circuit while the motor is running.
* capacitor-run motor :
A type of capacitor motor that has a capacitor and starting winding connected in series at all times.
* capacitor-start motor :
A single-phase motor with a capacitor. The capacitor gives the motor more starting torque.
* centrifugal switch :
A type of switch that operates using the centrifugal force created from the rotating shaft. The centrifugal switch activates and de-activates depending on the speed of the motor.
* direct current :
A current formed when electrons flow in one continuous direction.
* dual voltage motor :
A type of three-phase motor that operates on two voltage levels. Dual voltage motors allow the same motor to be used with two different power line voltages.
* electric motor :
A machine that converts electricity into mechanical energy or motion. An electric motor is a common power source for a mechanical system.
* efficiency losses :
A measure of the energy output versus the amount of input energy. The output energy is typically less than the input energy.
* electromagnetic induction :
The process in which current is induced in a magnetic field using a current-carrying coil. An AC generator produces a current through electromagnetic induction.
* field winding :
The conducting wire connected to the armature that energizes the pole pieces. Field windings are connected in series or parallel.
* generator :
A device that converts mechanical energy into electrical energy by magnetic induction.
* induction motor :
A type of AC motor that uses electrical current to induce rotation in the coils.
* magnet :
A device or object that attracts iron and produces a magnetic field.
* magnetic flux :
The area in and around a magnet that exhibits the powers of attraction and repulsion. Rotating an armature through lines of magnetic flux induces AC.
* motor nameplate :
A plate attached to a motor that displays all of the motor's information
* output shaft :
The rotating part on the AC motor that holds the rotor and allows it to turn.
* phase displacement :
The separation of the three phases in a three-phase motor. The windings are spaced 120º apart.
* reactance :
The resistance to the flow of alternating current due to inductance.
* resistance :
The opposition to current flow. Electricity flows in the path of least resistance.
* rotor :
The rotating part of a motor.
* running winding :
Heavy, insulated copper wire in a single-phase motor that receives the current for running the motor. The running winding remains connected when the starting winding is disconnected.
* secondary winding :
The second winding that current passes through in a transformer. The secondary winding contains fewer, but thicker wires that are wrapped into a coil.
* shaded-pole motor :
A single-phase motor that is 1/20 HP or less and is used in devices requiring low torque.

* sine wave :
The most common type of AC waveform. A sine wave consists of 360 electrical degrees and is produced by rotating machines.
* single voltage motor :
A type of three-phase motor that operates on only one voltage level. Single voltage motors are limited to having the same voltage as the power source.
* single-phase motor :
A type of motor with low horsepower that operates on 120 or 240 volts. Single-phase motors are often used in residential appliances like washing machines and air conditioners.
* slip :
The difference between a motor's synchronous speed and its speed at full load. Percent slip is a way to measure the speed performance of an induction motor.
* slip ring :
A conductive device attached to the end of a generator rotor that conducts current to the brushes. Slips rings are also used in AC wound rotor motors.
* split-phase motor :
A single-phase motor that consists of a running winding, starting winding, and centrifugal switch. The reactance difference in the windings creates separate phases, which produce the rotating magnetic field that starts the rotor.
: squirrel cage rotor :
A type of three-phase AC rotor that is constructed by connecting metal bars together at each end. It is the most common AC rotor type.
* starting winding :
Fine, insulated copper wire in a single-phase motor that receives current in the motor at start-up. When the motor reaches 60-80% of the full load, the starting winding is disconnected and the running winding remains in the circuit.
* stator :
The stationary part of a motor.
* stepped down :
In electricity, a phrase used to describe voltage adjustment. To step down voltage means to decrease voltage.
* stepped up :
In electricity, a phrase used to describe voltage adjustment. To step up voltage means to increase voltage.
* synchronous motor :
A constant-speed AC motor that does not use induction to operate. A synchronous motor needs DC excitation to operate.
* thermal switch :
A type of switch often found in split-phase motors that signals that the motor may overheat
* three-phase motor :
A motor with a continuous series of three overlapping AC cycles offset by 120 degrees. Three-phase power is used for all large AC motors and is the standard power supply that enters homes and factories.
* torque :
A force that produces rotation.
* transform :
To increase or decrease the voltage in a circuit
* wound rotor :
A type of three phase rotor that contains windings and slip rings. This motor type permits control of rotor current by connecting external resistance in series with the rotor windings.

 

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How to Test & Troubleshoot Electric Motors :

Step (1) Place safety glasses over your eyes. Any time you are repairing an electrical device, safety glasses should be your number one tool. Shut off all electric power to the motor, whether this is turning off a circuit breaker or removing fuses from the disconnect switch.

Step (2) Remove the wiring cover on the motor and set aside the screws so you do not lose them. Read the motor's nameplate data to confirm whether this is a low voltage 115 volt motor, a 230 volt motor, or a 3-phase 230 volt or high voltage 480 volt motor. This will determine the number of power leads the motor has. All single phase 115 volt and 230 volt motors have two wire leads that connect to the power supply. All 3-phase 230 volt and 480 volt motors have three wire leads that connect to the 3-phase power supply.

Step (3) Remove the plastic wire connectors that are connecting to the power supply. You may have to identify the power leads to the wires on the motor if it is a 3-phase motor. This will ensure the rotation will be correct when re-terminating the motor. Turn your volt ohm meter to the ohm setting. The meter should read OL (open lead) or zero ohms. Take one lead and touch it to the case of the motor and test each motor lead. The ohm meter should read OL or zero ohms. If a reading of any ohms is observed you may have a direct short in the motor windings; the motor may be bad. Some motors, especially the 3-phase type, may have a very large resistance reading--in the 20 megaohms range or larger. This may be fine, or this may be a sign that the bearings are going bad as the motor may have deteriorating windings due to excessive heat.

Step (4) Testing single phase motors, whether they are 115 volt or 230 volt, with a capacitor is a little trickier but can still be accomplished. Remove the capacitor from its housing, being careful no to touch the exposed leads. The capacitor is like a battery and stores a high voltage charge. Turn your volt ohm meter to volts and carefully touch to the bare leads of the capacitor. If voltage is read, the capacitor still contains a charge. Holding the leads of the meter to the capacitor should show it discharging, Continue until zero voltage is observed on the meter. Most modern volt ohm meters have a capacitor testing switch on them and it is a simple matter to determine the status of the capacitor. In most cases the capacitor only needs to be replaced on these type of single phase motors.

* Check for blown line fuses or tripped breakers first, if your motor won't start at all. If it has failed while running, allow the motor to cool and then try to reset it.

Heavy duty electrical motors most often consist of split-phase induction motors designed for heavy duty assignments. As split-phase motors use a separate starter winding, these require a capacitor in the starting circuit to provide increased starting power. Failure of split-phase induction motors is often corrected by troubleshooting the capacitor function as described.

Diagnosing Capacitor Malfunction

Step (1) Attempt to start the induction motor. In there is a malfunction, the motor hums but does not start.
Step (2) Rule out malfunction of the centrifugal starter switch by spinning the rotor shaft by hand. If the shaft is frozen the problem is in the switch, and it most be replaced.
Step (3) If the rotor shaft rotates freely by hand, attempt to start the motor. If it starts the switch is either defective or stuck in the closed position, and the motor will stop running. Use electrical contact cleaner to clean the switch. Replace the switch if cleaning fails to correct problem.
Step (4) Rule out a malfunctioning centrifugal switch as above before assuming a failed capacitor function.
Once the switch has been ruled out, a motor that continues to hum ( has current ) but is too weak or otherwise fails to start may be the result of a short or open circuit in the capacitor.
Troubleshooting the Capacitor :
Step (1) Locate the capacitor, which is usually mounted on the side of the induction engine.
Step (2) Remove electrical wires from the two male contacts on the front of the capacitor.
Step (3) Set the volt ohmmeter to the 100 scale and connect the positive and negative leads from the volt ohmmeter to the two contacts of the capacitor.
Step (4) Observe the meter reading. If the needle jumps immediately to zero ohms and gradually drifts back to a high ohm reading, the capacitor is functional and is not the problem.
Step (5) A meter reading that registers steady zero ohms or steady high ohms indicates the capacitor is malfunctioning and should be replaced.
Step (6) Double check meter results by reversing meter leads to the capacitor and re-checking the readings.

Tips : One indicator of an open circuit in a faulty capacitor is high frequency interference in nearby radios when the motor is use.

 

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Flickering fluorescent tubes can cause the ballast to overheat and fail prematurely! They can even cause a starter to burn out! Don't wait too long to fix the problem or you may end up with a bigger repair!

look at the tube! If either tube appears to be very dark near either end the tube is defective or close to failure.

* An electrical short is often called a short circuit. It is a path for electrical current to flow that is the result of a defect or a breakdown of the electrical circuit. Because it's a clear path for electrical current, electrical shorts can be found by using an ohmmeter, which measures resistance, which is measured in units called ohms, to electrical current. A typical electrical short will have a very low resistance, usually less than a few ohms. By using an ohmmeter and a few simple troubleshooting techniques, you can identify electrical shorts.

 

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Electric Wiring :

If we connect a voltmeter between a live part ( e.g. the Line Conductor of a socket outlet ) and earth , we read 230V ;
The conductor is at 230V and the earth at Zero . The Earth provides a path to complete the circuit , We would measure nothing at all if we connected our voltmeter , say the positive 12v terminal of a car battery and Earth , as in this case the Earth plays no part in any circuit ,

Colours of indicator lights and their meanings

Colour : RED : Emergency Explanation : Warning of potential danger or a situation which requires immediate action
Typical application : • Failure of pressure in the lubricating system , • Temperature outside specified (safe) limits , • Essential equipment stopped by action of a protective device ,
Colour : Yellow : Meaning Abnormal condition , Explanation Impending critical condition , • Temperature (or pressure) different from normal level , • Overload, which is permissible for a limited time ,
• Reset ,
Colour : Green : Meaning : Normal Explanation : Indication of safe operating conditions or authorization to proceed, clear way Typical application : • Cooling liquid circulating • Automatic tank control switched on • Machine ready to be started
Colour : Blue : Meaning : Enforced action : Explanation : Operator action essential Typical application : • Remove obstacle • Switch over to Advance ,
Colour : White : Meaning : No specific meaning , Explanation : Every meaning: may be used whenever doubt exists about the applicability of the colours RED, YELLOW or GREEN; or as confirmation

Crimp terminals :

Crimp terminals are used for connecting wire by means of a screw joint to: bus-bar, switchgear housing, electric device and apparatus, etc. Terminals with rated sizes up to 0,5 - 6 mm² are designed in principle for a particular wire cross-sections, e.g. 6 mm² terminal can be used for the wires with a cross-section of 4 to 6 [mm²]. Terminal with a cross-section over 6 mm² can be used only for defined wire cross-section. Crimp terminals can only be used on stranded wire and cannot be used on solid cable.←←

Here are some of the more popular crimp terminals : Ring terminals , Fork terminals , Blade terminals , Fully insulated Female push-ons , Butt connectors , Butt connectors are used to join two wires together. You can also find terminals such as pins, male tabs, piggy back, male and female bullets.
Do not forget that the color is also important. Each color represents a different size of crimp terminal. Red ones should be used for the wires with a cross-section of 0,75mm2 to 1,5mm2. Blue ones for the wires from 1,5mm2 to 2,5mm2, and yellow terminals are for the wires with a cross-section of 4mm2 to 6mm2.

RED : wire size : 0,5 - 1,5mm BLUE : wire size 1,5 - 2,5mm YELLOW : 4 - 6mm

Colours of push-buttons and their meanings :
Colour RED : Meaning : Emergency ,
Typical application : * Emergency stop * Fire fighting

Colour YELLOW :
Meaning : abnormal conditions
Typical application : Intervention, to suppress abnormal conditions or to avoid unwanted changes

Colour GREEN :
Meaning : Normal ,
Typical application : Start from safe condition

Colour BLUE :
Meaning : Enforced action ,
Typical application : Resetting function

Colour WHITE :
Meaning : No specific meaning ,
Typical application : * Start/ON * Stop/OFF

Colour Gray :
Meaning : No specific meaning ,
Typical application : * Start/ON * Stop/OFF


Colour BLACK :
Meaning : No specific meaning ,
Typical application : * Start/ON * Stop/OFF

Insulation resistance : Pat ;
Insulation resistance is normally checked by applying 500V dc between both live conductors (line and neutral) connected together and protective earth when testing a Class I appliance

Competence of the inspector
A final consideration when carrying out inspection and tests is the competence of the inspector. Any person undertaking these duties must be skilled and experienced and have sufficient knowledge of the type of installation. It is the responsibility of the inspector to:

* ensure no danger occurs to people, property and livestock
* confirm that test and inspection results comply with the requirements of BS 7671 and the designer’s requirements
* express an opinion as to the condition of the installation and recommend remedial works
* make immediate recommendations, in the event of a dangerous situation, to the client to isolate the defective part.

The inspection process

In new installations, inspection should be carried out progressively as the installation is installed and must be done before it is energised. As far as is reasonably practicable, an initial inspection should be carried out to verify that:

* all equipment and material is of the correct type and complies with applicable British Standards or acceptable equivalents
* all parts of the fixed installation are correctly selected and erected no part of the fixed installation is visibly damaged or otherwise defective
* the equipment and materials used are suitable for the installation relative to the environmental conditions.

 

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EXTENT AND FREQUENCY OF INSPECTION & TESTING

WHAT IS REQUIRED TO BE INSPECTED AND TESTED ? All types of mains powered electrical portable, moveable, hand-held, stationary, fixed, equipment for 'building-in', I.T. equipment and extension leads are required to be regularly inspected and tested.

It should be noted that provision of new appliance does not exempt the need for formal Inspection and Testing. Manufacturer's warranties only provide for repair or replacement of a faulty device, they do not guarantee that a new device is electrically safe.
Equipment Types :

* Portable Appliance
An appliance of less than 18gm in mass that is intended to be moved while in operation or an appliance which can easily be moved from one place to another, e.g.;- Toaster, Food Mixer, Vacuum Cleaner, Fan Heater

* Movable Equipment (sometimes called transportable)
This is equipment that is either:
18Kg or less in mass and not fixed, e.g. Electric Fire, or equipment with wheels, castors or other means to facilitate movement by the operator as required to perform its intended use, e.g. Air Conditioning Unit.
* Hand-Held Appliances or Equipment
This is portable equipment intended to be held in the hand during normal use e.g.
Hair Dryer, Power Drill, Soldering Iron, Angle Grinder

* Stationary Equipment or Appliances
This equipment has a mass exceeding 18Kg and is not provided with a carrying handle e.g. Refrigerator, Washing Machine, Dishwasher

* Fixed Equipment/Appliances
This is equipment or an appliance which is fastened to a support or otherwise secured in a specified location e.g. Convector Heater, Water Heater, Heated Towel Rail, Production Machinery, Fixed Tools

* Appliances/Equipment for Building-In
This equipment is intended to be installed in a prepared recess such as a cupboard or similar. In general, equipment for building-in does not does not have an enclosure on all sides because on one or more of the sides additional protection against electric shock is provided by the surroundings e.g. Built-In Cooker, Built-In Dishwasher

* Information Technology Equipment (Business Equipment)
Information technology equipment includes electrical business equipment such as computers and mains powered telecommunications equipment and other equipment for general business use e.g. Mail Processing Machines, Electric Plotters, Trimmers, PCs, VDUs, Data Terminal Equipment, Telephones, Printers, Photo-Copiers, Power Packs

* Extension Leads, RCD Extension Leads & RCD Adaptors
The use of extension leads other than for temporary power supplies should be avoided were possible. RCDs are required to be checked for operation.

* The Environment - equipment installed in a benign environment will suffer less damage than equipment used in an arduous environment.

* The Equipment's Construction - Class 1 equipment is dependant upon the connection with earth of the fixed installation.

* The Equipment Type - Hand-held appliances are more likely to be damaged than fixed appliances. If they are Class I appliances then the risk of danger is increased as safety is dependant upon the continuity of the protective (earth) conductor from the plug to the appliance. The initial frequency of inspection and testing should comply with the Institution of Electrical Engineer’s Code of Practice for the In-Service Inspection and Testing of Electrical equipment.

Insulation resistance test

insulation resistance test being conducted on a twin and earth cable between the line and cpc at the distribution board end of the cable.
The reading obtained should be greater than 100 MΩ, indicating that the insulation resistance is satisfactory and that the supply is safe to put on. But what would the instrument indicate in the situation ?

In the situation an insulation resistance test is again being conducted between line and cpc. However, this time a nail has penetrated the sheath of the cable, breaking the cpc and touching the line conductor .When the test is done the instrument may read greater than 100 MΩ, indicating that the insulation resistance is acceptable and that it is safe to connect the supply. However, we can clearly see that it is not. Beyond the break in the cpc, the line and cpc are connected. If the supply was now connected to the cable we would have a potentially lethal situation, as all the metal work connected to the cpc will become live. Automatic disconnection will not take place as the break in the cpc means there is no longer a return path. The metalwork will remain live until someone touches it – which could result in a fatal electric shock In this case,
** if we had conducted a Continuity Test of the cpc before the insulation resistance test, we would have identified that the cpc was broken. Action could then have been taken to remedy the situation

Electrical Terms :

CCT - Circuit
CCU - Cooker Control Unit
CPC - Circuit Protective Conductor
CU - Consumer Unit
The CNE conductor (combined neutral and earth) PEN
EEBAD - Earthed Equipotential Bonding And Automatic Disconnection Of Supply ( Old ) must be replace now ,
ELV - Extra Low Voltage = Below 50V AC \ 120V Ripple Free DC
FCU - Fused Connection Unit
FELV - Functional Extra Low Voltage
HBC - High Breaking Capacity
HRC - High Rupturing Capacity
HV - High Voltage
LV - Low Voltage = 50V - 1000V AC \ 1500V Ripple Free DC
MCB - Miniature Circuit Breaker
MCCB - Moulded Case Circuit Breaker
MD - Maximum Demand
MICC - Mineral Insulated Copper Cable aka Pyro
PAT - Portable Appliance Testing
PELV - Protected Extra Low Voltage
PEN - Protective Earthed Neutral
PFC - Prospective Fault Current
PME - Protective Multiple Earthing
PSCC - Prospective Short Circuit Current
PVC - Poly Vinyl Chloride
RCBO - Residual Current Breaker With Integral Overload Protection
RCCB - Residual Current Circuit Breaker
RCD - Residual Current Device
SELV - Separated Extra Low Voltage
SRCBO's - Socket Outlet Incorporating RCBO's
SWA - Steel Wire Armour (Cable)
UPS - Uninterruptible Power Supply
VD - Voltage Drop

A - Amp
W - Watt
V - Volt
R - Resistance
Z - Impedance
mA - milliampere
mV - millivolt
kW - Kilowatt
kV – Kilovolt

 

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Alternating current circuit calculations :

Impedance ,

In DC, circuits ,the current is limited by résistance . In AC ,circuits , the current is limited by Impedance ( Z ) Résistance & Impedance are measured in Ohms ,

For this calculation , Ohms law is used and ( Z ) is substituted for ( R ) U – Z = I or voltage ( U ) ÷ impedance ( Ohms ) = Current ( Amperes )
* the voltage applied to a circuit with an impedance of 6Ω , is 200 volts , calculate the current in the circuit ,
U – Z = I ( 200 ÷ 6 = 33.33A )
* the current in a 230V single–phase motor is 7.6A calculate the impedance of the circuit , U – I = Z ( 230 ÷ 7.6 = 30.26Ω )
* a discharge lamp has an impedance of 265Ω and the current drawn by the lamp is 0.4A , calculate the voltage
Z x I = U ( 265 x 0.4 = 106 volts )
* the current through an impedance of 32Ω is 8A , calculate the voltage drop across the impedance U = I x Z = 8 x 32 = 256v
* the current through an electric motor is 6.8A at 230V , calculate the impedance of the motor , U = I x Z
( transpose for Z ) Z = U – I ( 230 ÷ 6.8 = 33.82Ω )
* an AC . coil has an impedance of 430Ω calculate the voltage if the coil draws a current of 0.93A
U = I x Z ( U = I x Z 0.93 x 430 = 400V )

* a mercury vapour lamp take 2.34A when the mains voltage is 237V calculate the impedance of the lamp circuit ?
* an inductor has an impedance of 365Ω how much current will flow when it is connected to a 400V ac supply ?
* a coil of wire passes a current of 55A when connected to a 120V dc supply but only 24.5A when connected to a 110V ac supply calculate (a) the résistance of the coil (b) its impedance ,

Test to measure the impedance of an earth fault loop were made in accordance with BS-7671 and the results for five different installations are given below , for each case calculate the value of the loop impedance ,

(a) test voltage ac ( V ) 9.25 : Current ( A ) 19.6 (b) test voltage ac ( V ) 12.6 : Current ( A ) 3.29
(c) test voltage ac ( V ) 7.65 : Current ( A ) 23.8 (d) test voltage ac ( V ) 14.2 : Current ( A ) 1.09 (e) test voltage ac ( V ) 8.72 : Current ( A ) 21.1

* the choke in a certain fluorescent-fitting causes a voltage drop of 150V when the current through it is 1.78A , calculate the impedance of the choke ,
* the alternating voltage applied to a circuit is 230V and the current flowing is 0.125A , the impedance of the circuit is ,
(a) 5.4Ω (b) 1840Ω (c) 3.5Ω (d) 184Ω ,
* an alternating current of 2.4A flowing in a circuit of impedance 0.18Ω produces a voltage drop of
(a) 0.075V (b) 13.3V (c) 0.432V (d) 4.32V ,
* when an alternating e.m.f of 150V is applied to a circuit of impedance 265Ω , the current is ,
(a) 39 750A (b) 1.77A (c) 5.66A (d) 0.566A

We will assume that the résistance of the circuits is so low that it may be ignored and that the only opposition to the flow of current is that caused by the inductive reactance ,
The formula for inductive reactance , ( is XL = 2nfL ( answer in ohms )
Where L is the inductance of the circuit or coil of wire and is stated in henrys ( H ) f is the frequency of the supply in hertz (Hz )
* calculate the inductive reactance of a coil which has an inductance of 0.03 henrys when connected to a 50Hz supply
( XL = 2nfL ( 2 x 3 . 142 x 50 x 0.03 = 9.42Ω
* calculate the inductive reactance of a coil when connected to a 60Hz supply , XL 2nfL ( = 2 x 3. 142 x 60 x 0.03 = 11.31Ω )
It can be seen from this calculation that the frequency increases the inductive reactance will also increase ,

 

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Working knowledge :

What we call "Electricity" is actually made up of three parts.

Real Power (Kw, Mw),
Apparent Power (Kva),
Reactive Power (Kvar).
These 3 parts form the "Power Triangle"

Real Power (Kw) is the part of the triangle which results in real work done, in the form of heat energy.

Apparent Power is that portion of the power triangle that we actually measure.

And then....there is Reactive Power....which serves no real function at all.

The phase angle between Real Power and Apparent Power in the power triangle is identified as the angle "q" which is the Greek letter "THETA". The size, in degrees, of that angle determines the size of the Reactive Power leg of the triangle. The cosine of that angle is called Power factor or pf and the value of the pf is inversely proportional to the amount of reactive power you are generating. What this means is that the smaller the angle q, the less Reactive Power you are making and the greater your Power Factor is.

Electrical

A = Ampere
V = Volt
W = Watt
Ω = Ohm
F = Farad

Power / Energy

HP = horsepower
W = watt
kW = kilowatt
kWh = kilowatt-hours

I = Current (ampere)
U = Voltage (volt)
R = Resistance (ohm)

Electrical power

P = U x I x PF / 1000
P =Power in kW (1-phase)
PF = Power factor

P = U x I x PF x √2 / 1000
P =Power in kW (2-phase)

P = U x I x PF x √3 / 1000
P =Power in kW (3-phase)

Conversion factors

Power
1 hp = 0,736 kW 1 kW = 1,36 hp
1 hp = 0,746 kW (UK,US) 1 kW = 1,34 hp (UK;US)
1 kcal/h = 1,16 W 1 W = 0,860 kcal/h

Energy
1 kpm = 9,80665 J 1 J = 0,102 kpm
1 cal = 4,1868 J 1 J = 0,239 cal
1 kWh = 3,6 MJ 1 MJ = 0,278 kWh

Mass
1 lb = 0,454 kg 1 kg = 2,20 lb
Area
1 acre = 0,405 ha 1 ha = 2,471 acre

Length
1 mile = 1,609344 km 1 km = 0,621 mile
1 yd = 0,9144 m 1 m = 1,09 yd
1 ft = 0,3048 m 1 m = 3,28 ft
1 in = 25,4 mm 1 mm = 0,039 in

 

[amberleaf]

Insulation Résistance Test :

Insulation résistance is normally checked by applying 500V dc
Between both Live Conductors ( Line & Neutral ) and Protective Earth when Testing a Class 1 Appliance .

Mathematical :

˂ Less than .
≤ Less than or Equal to .
˃ More than .
≥ More than or Equal to .

Inspection checklists :

To ensure that all the requirements of the Regulations have been met, inspection checklists should be drawn up and used as appropriate to the type of installation being inspected. Examples of suitable checklists are given in which follows.

Switchgear ( tick if satisfactory )

All switchgear is suitable for the purpose intended .
Meets requirements of the appropriate BS EN standards .
Securely fixed and suitably labelled .
Suitable glands and gland plates used (526.1) .
Correctly earthed .
Conditions likely to be encountered taken account of, i.e. suitable for the environment .
Correct IP rating .
Suitable as means of isolation .
Complies with the requirements for locations containing a bath or shower .
Need for isolation, mechanical maintenance, emergency and functional switching met .
Fireman switch provided, where required .
Switchgear suitably coloured, where necessary .

Lighting controls ( tick if satisfactory )

Light switches comply with appropriate British Standard .
Switches suitably located .
Single-pole switches connected in phase conductor only .
Correct colour-coding of conductors .
Correct earthing of metal switch plates .
Switches out of reach of a person using bath or shower .
Switches for inductive circuits (discharge lamps) de-rated as necessary .
Switches labelled to indicate purpose where this is not obvious .
All switches of adequate current rating .
All controls suitable for their associated luminaire .

Lighting points ( tick if satisfactory )

All lighting points correctly terminated in suitable accessory or fitting .
Ceiling roses comply with appropriate British Standard .
No more than one flexible cord unless designed for multiple pendants .
Devices provided for supporting flex used correctly .
All switch wires identified .
Holes in ceiling above ceiling rose made good to prevent spread of fire .
Ceiling roses not connected to supply exceeding 230V .
Flexible cords suitable for the mass suspended .
Lamp holders comply with appropriate British Standard .
Luminaire couplers comply with appropriate British Standard .

Conduits ( general ) ( tick if satisfactory )

All inspection fittings accessible .
Maximum number of cables not exceeded .
Solid elbows used only as permitted .
Conduit ends reamed and bushed .
Adequate number of boxes .
All unused entries blanked off .
Lowest point provided with drainage holes where required .
Correct radius of bends to prevent damage to cables .
Joints and scratches in metal conduit protected by painting .
Securely fixed covers in place adequate protection against mechanical damage .

Wiring accessories ( general requirements) (tick if satisfactory )

All accessories comply with the appropriate British Standard
Boxes and other enclosures securely fastened
Metal boxes and enclosures correctly earthed
Flush boxes not projecting above surface of wall
No sharp edges which could cause damage to cable insulation
Non-sheathed cables not exposed outside box or enclosure
Conductors correctly identified
Bare protective conductors sleeved green and yellow
All terminals tight and contain all strands of stranded conductor
Cord grips correctly used to prevent strain on terminals
All accessories of adequate current rating
Accessories suitable for all conditions likely to be encountered
Complies with the requirements for locations containing a bath or shower
Cooker control unit sited to one side and low enough for accessibility and to prevent trailing flexes
across the radiant plates
Cable to cooker fixed to prevent strain on connections

Socket outlet ( tick if satisfactory )

Complies with appropriate British Standard and is shuttered for household and similar installations
Mounting height above floor or working surface is suitable
All sockets have correct polarity
Sockets not installed in bath or shower zones unless they are shaver-type socket or SELV
Sockets not within 3m of zone 1
Sockets controlled by a switch if the supply is direct current
Sockets protected where floor mounted
Circuit protective conductor connected directly to the earthing terminal of the socket outlet on a sheathed wiring installation
Earthing tail provided from the earthed metal box to the earthing terminal of the socket outlet
Socket outlets not used to supply a water heater with uninsulated elements

Rigid metal conduits (tick if satisfactory)
Complies to the appropriate British standard
Connected to the main earth terminal
Line and neutral cables contained within the same conduit
Conduits suitable for damp and corrosive situations
Maximum span between buildings without intermediate support

Rigid non-metallic conduits (tick if satisfactory)
Complies with the appropriate British Standard
Ambient and working temperature within permitted limits
Provision for expansion and contraction
Boxes and fixings suitable for mass of luminaire suspended at expected temperatures

Flexible metal conduit (tick if satisfactory)
Complies with the appropriate British Standard
Separate protective conductor provided
Adequately supported and terminated

Trunking (tick if satisfactory)
Complies to the appropriate British Standard
Securely fixed and adequately protected against mechanical damage
Selected, erected and rooted so that no damage is caused by ingress of water
Proximity to non-electrical services
Internal sealing provided where necessary
Hole surrounding trunking made good
Band 1 circuits partitioned from band 2 circuits, or insulated for the highest voltage present .
Circuits partitioned from band one circuits, or wired in mineral-insulated and sheathed cable .
Common outlets for band 1 and band 2 circuits provided with screens, barriers or partitions .
Cables supported for vertical runs

Metal trunking (tick if satisfactory )
Line and neutral cables contained in the same metal trunking
Protected against damp corrosion
Earthed
Joints mechanically sound, and of adequate earth continuity with links fitted

Plant , Equipment & component failure :

It is said that nothing lasts forever and this is certainly true of electrical equipment there will be some faults that you will attend that will be the result of a breakdown simply caused by wear & tear , although it must be said that planned maintenenance systems and regular testing and inspections can extend the life of equipment , some common failures on installations and plant are :
* switches not operating – due to age .
* motors not running – new brushes required .
* lighting not working – lamps life expired .
* fluorescent luminaire not working – new lamp or starter needed .
* outside PIR not switching – ingress of water causing failure.
* corridor socket outlet not working due to poor contacts created by excessive use / age .

The intention of the measure is to phase out less efficient lamps in favour of products with greater energy efficiency. A brief description of the lamps affected by the measure follows below along with a summary of main characteristics

A. Incandescent lamps (General Lighting Service (GLS))
These lamps are the traditional filament lamps which have been in domestic use for decades and provide a bright light source when made with transparent glass. They are very low efficiency lamps compared with other lamps (CFLs in particular) but are generally available in good quality, and provide good performance.

B. Conventional halogen lamps (Halo conv)
Standard halogen lamps consume at best, 15% less energy than GLS lamps for the same light output. Many of these lamps are low voltage lamps which are more efficient that mains voltageones but which require a transformer either in the luminaire or in the lamp itself. They provide good quality light.

C. Halogen lamps with xenon filling (C-class)
These are recent technology lamps with xenon filling and will use approximately 25% less energy for the same light output as GLS lamps. These lamps come in two types, one which is placed in glass bulbs, shaped like incandescent lamps, which are compatible with existing luminaries (retro C), and halogen socket c type lamps which can only be used in special halogen sockets (halosocket C). Lamps provide good quality light and performance.

D. Halogen lamps with infrared coating (B-class)
These lamps are new technology, with an application of infrared coating to the wall of the halogen lamp capsule making the lamp considerably more efficient. However, this is only possible with low voltage lamps and therefore a transformer is required. Currently only one manufacturer produces these lamps with a fitting so that they can fit traditional sockets. Due to heat issues, these are only available up to the equivalent of 60W GLS bulbs. They provide a bright light source and good performance and are estimated to provide 45% energy savings over GLS lamps

E. Compact fluorescent lamps (CFLs)
These include an integrated ballast, fit into existing GLS sockets, and are produced with both bare tubes and also with a traditional bulb-shaped cover. They have a long lifetime and vary in their energy efficiency, being estimated to use between 20-35% of energy of that needed for GLS lamps. CFLs are sometimes criticised by consumers resulting from lingering perceptions over poor light quality and it is recognised that long periods of close-up use can have adverse effects on those with pre-existing photo-sensitive conditions.

 

[pipster1973]

thanks very much this has helped me no endl

 

[amberleaf]

On and Off – load devices :

Not all devices are designed to switch circuits “ on or off “ it is important to know that when a current is flowing in a circuit , the operation of a switch ( or disconnector ) to break the circuit will result in a discharge of energy across the switch terminals ,

You may well have had this happen when entering a dark room and switching on the light ,
Where for an instant you may see a blue flash from behind the switch plate . this is actually the arcing of the current as it dissipates and makes contact across the switch terminals . a similar arcing takes place when circuits are switched off or when protective devices operate thus breaking fault current levels .

Fundamentally , an isolator is designed as an off-load device and is usually only operated after the supply has been made dead and there is no load current to break . an on-load device can be operated when current is normally flowing and is designed to make or break load current .

An example : of an on-load device could be a circuit breaker , which is not only designed to make and break load current
But has been designed to withstand make and break high levels of fault current ,

* all portable appliances should be fitted with the “ Simplest form of Isolator “. a fused plug . this , when unplugged from the socket-outlet . provides complete isolation of the appliance from the supply ,

* Meltdown of plastic connector due to overcurrent : ( Fire ) ←
* Meltdown of insulation due to Overcurrent ,

When insulation of conductors and cables fail . it is usually due to one or more of the following ,
* poor installation methods .
* poor maintenance .
* excessive ambient temperatures .
* high fault current levels .
* damage by third party .

When a protective device has been operated correctly and this device was the nearest device to the fault ( Discrimination ) is said to have occurred

Luminaires :
The most common fault with luminaires is expiry of lamp life . which obviously only requires replacement .
Discharge lighting systems employ control gear which on failure will need replacement as they cannot be repaired , discharge type lighting may have problems with the control circuit ,
Common items of equipment in the luminaire control circuit are :
* the capacitor used for power factor correction . if this has been broken down it would not stop the lamp operating but would prevent the luminaire operating efficiently ,
* the choke or ballast used to create high p.d to assist in the lamp starting . a common item which could break down and need replacement ,
* the starter , which is used to assist the discharge across the lamp when switched on at the start , this is the usual part to replace when the lamp fails to light .

Many fluorescent luminaires have starter – less electronic control gear , which is not only quick-start with increased efficiency , but requires less maintenance . they have a longer lamp life but when the quick-start unit fails it will need replacement ,

Risk of high frequency on high capacitive circuits :

Capacitive circuits could be circuits with capacitors connected to them or some long runs of circuits wiring which may have a capacitive effect .
This is usual on long runs of mineral-insulated cables . when working on such circuits no work should commence until the capacitive effect has been discharged . in some cases it would be practical to discharge capacitors manually by shorting out the capacitor ,

MULTIPLE CHOICE :

Choose the one alternative that best completes the statement or answers the question.

1) Electrons are made to flow in a wire when there is
A) an imbalance of charges in the wire.
B) more potential energy at one end of the wire than the other.
C) a potential difference across its ends. **

2) An ampere is a unit of electrical
A) pressure.
B) current. **
C) resistance.
D) all of these.
E) none of these.

3) A wire that carries an electric current
A) is electrically charged.
B) may be electrically charged. **
C) is never electrically charged.

4) A coulomb of charge that passes through a 6-volt battery is given
**A) 6 joules. B) 6 amperes. C) 6 ohms. D) 6 watts. E) 6 Newton’s.

5) Which statement is correct?
A) Charge flows in a circuit. **
B) Voltage flows through a circuit.
C) Resistance is established across a circuit.
D) Current causes voltage.

6) Electrons move in an electrical circuit
A) by being bumped by other electrons.
B) by colliding with molecules.
C) by interacting with an established electric field. **
D) because the wires are so thin.
E) none of these.

7) Heat a copper wire and its electric resistance
A) decreases. B) remains unchanged. C) increases. **

8) Stretch a copper wire so that it is thinner and the resistance between its ends
A) decreases. B) remains unchanged. C) increases. **

9) A wire carrying a current is normally charged
A) negatively. B) positively. C) not at all. **

10) In an ac circuit, the electric field
A) increases via the inverse square law.
B) changes magnitude and direction with time. **
C) is everywhere the same.
D) is non-existent.
E) none of these.

11) The current through a 10-ohm resistor connected to a 120-V power supply is
A) 1 A.
B) 10 A.
C) 12 A. **
D) 120 A.
E) none of these.

12) A 10-ohm resistor has a 5-A current in it. What is the voltage across the resistor?
A) 5 V
B) 10 V
C) 15 V
D) 20 V
E) more than 20 V **

13) When a 10-V battery is connected to a resistor, the current in the resistor is 2 A. What is the resistor's value?
A) 2 ohms
B) 5 ohms **
C) 10 ohms
D) 20 ohms
E) more than 20 ohms

14) The source of electrons in an ordinary electrical circuit is
A) a dry cell, wet cell or battery.
B) the back emf of motors.
C) the power station generator.
D) the electrical conductor itself. **
E) none of these.

15) The source of electrons lighting an incandescent ac light bulb is
A) the power company.
B) electrical outlet.
C) atoms in the light bulb filament. **
D) the wire leading to the lamp.
E) the source voltage.

16) A woman experiences an electrical shock. The electrons making the shock come from the
A) woman's body. **
B) ground.
C) power plant.
D) hairdryer.
E) electric field in the air.

17) In a common dc circuit, electrons move at speeds of
A) a fraction of a centimeter per second. **
B) many centimeters per second.
C) the speed of a sound wave.
D) the speed of light.
E) none of these.

18) When a light switch is turned on in a dc circuit, the average speed of electrons in the lamp is
A) the speed of sound waves in metal.
B) the speed of light.
C) 1000 cm/s.
D) less than 1 cm/s. **
E) dependent on how quickly each electron bumps into the next electron.

19) Alternating current is normally produced by a
A) battery. B) generator. **
C) both of these. D) neither of these.

20) The electric power of a lamp that carries 2 A at 120 V is
A) 1/6 watts. B) 2 watts. C) 60 watts. D) 20 watts. E) 240 watts. **

 

[pipster1973]

are all these mock or gola and where do you get them

 

[amberleaf]

Power Dissipation :
All components have résistance so when a current flows through them power is dissipated in most cases in the form of heat. It is something to be aware of in the selection of components to be used in a circuit that the power ratings are not exceeded, examples are bulbs and resistors

Find the power dissipated by the bulb (Résistance ) of bulb = 100 ohms)
To find the power dissipated in the bulb which has a résistance of 100Ω.
If the formula Power = I x V watts is to be used the following data must be known: current flowing
through the bulb and voltage across the bulb
As the 200ohm resistor and the lamp are in series
then: Rt = 200 + 100 = 300Ω

mock learning curve

• Type AAA is the smallest of the above batteries and also produces the smallest amount of current (somewhere in the region of ˃10 milliamps over an extended period). Used in musical IPODS, and infra red controllers for televisions etc.

• Type AA one of the most used batteries, can be found in small radios, torches, toys, cassette players etc. This type can readily supply current of ˃ ˃ 40 milliamps over long periods.

• Types C, D can provide a much larger current region of ˃ 100 milliamps over extended periods and are used in power torches and large portable musical centres. Note the above batteries can provide much larger current over shorter periods.

• The PP3 battery has an output voltage of 9V. It is used extensively in small radios and also in smoke alarms. It can provide a continuous current output of 20 milliamps. ˂

The magnetic field is produced in two ways :

Permanent magnets (this method used only in the cheaper type of motors) Field coils which are wound around soft iron cores known as the FIELD
POLES.
Thus when current is passed through the field coil the soft iron core is magnetised. Motors must have a least two field poles to have a north/south pole arrangement

1µF = 1 microFarad = 1x10-6 Farads = 1 millionth of a Farad

1nF = 1 nanoFarad = 1x10-9 Farads = 1 billionth of a Farad

1pF = 1 picoFarad = 1 x 10-12 Farads = 1 trillionth of a Farad

if you have a Transformer: 28 VA / 12 volts rating and you're testing the power pack would have 2.33 amps available ( 28 ÷ 12 = 2.33 ).

Tell me and I forget, show me and I remember, involve me and I understand.

* When an initial inspection and test should be carried out ? During and on completion, before being put into service
The precautions to be taken during an inspection and test ? Avoid danger to persons, livestock and damage to property

a) Within the code IP2X what is represented by: ( i) 2 : ii) X )
b) State the level of protection offered by IP4X
a) i) standard finger 80mm long x 12mm diameter and no penetration by 12.5mm diameter sphere
ii) unspecified regarding the protection provided
b) Protection against small items 1.0mm diameter

State the three general requirements to which the installed equipment must conform when carrying out an initial inspection
* The equipment is in compliance with standards i.e. To the correct BS or BSEN
* Correctly selected and erected in accordance with BS7671
* It is not visibly damaged

State three requirements of the Electricity at Work Regulations regarding test instruments ?
* Equipment must be:
* Constructed,
* Maintained and Used in a way to prevent danger

State three human senses that could be used during an inspection of an installation ?
All of the senses could be used:-
* Sight,
* Smell,
* Hearing,
* Touch (give examples) Some smells taste

Conduit
* Fixings (correct number and type of saddle)
* Couplings tightened
* Running couplings locknuts tightened
* Box lids fitted complete with screws
* Vice marks removed
* Damaged finishes restored
* External protective conductors installed

Use of Class II equipment or equivalent insulation
* Non-conducting locations absence of protective conductors
* Earth free-local equipotential bonding presence of earth-free equipotential bonding conductors
* Electrical separation

Inspection
Inspection shall precede testing and shall normally be done with that part of the installation under inspection disconnected from the supply

HSE Guidance Note GS-38 Approved Voltage Tester← this will come up -&-

* Adequate insulation
* Have coloured leads to distinguish one lead from the other
* Have finger barriers
* Maximum of 2mm / 4mm exposed probe
* Flexible and Robust
* Sheathed leads to prevent damage
* Long enough for their purpose
* No accessible parts even if the lead is loose
* Have fused leads

Avoid Damage to Property

* Is there an RCD in the circuit
* Are there computers on line
* Is there electronic equipment in the circuit
* Could gaskets be damaged when removing covers
* Are all the loads disconnected
* Is there any equipment or processes which may be damaged if disconnected for long periods of time
* Is there any essential equipment which cannot be turned off

Avoid Danger to Persons
* Have you checked to see if any essential services are supplied from the board e.g emergency lighting, fire alarms, life-support equipment, UPS systems, gas monitoring systems, etc.
* Have you isolated the circuit correctly
* Have you discharged any capacitors
* Is the test equipment appropriate for the environment e.g. intrinsically safe
* Are you using long test leads that could cause people to trip over
* Have you informed people of the dangers

Initial Verification ← this will come up -&-

Every installation shall, during erection and on completion before being put into service be inspected and tested to verify , so far as is reasonably practicable that the requirements of the Regulations have been met.
Precautions shall be taken to avoid danger to persons and damage to property and installed equipment during the inspection and testing

Suppose we need to find out how many cables of overall diameter 3 mm we can install in a 50mm x 50mm steel trunking ,

Total area of trunking : ( 50 x 50 = 2500mm2 )

Space available for cables ( 45% )

( 2500 x 45 ÷ 100 = 1125mm2 )
This leaves 2500 – 1125 = 1375mm2 of air space within the trunking
Space occupied by one cable : ) π d2 / 4 = π x 3;2 / 4 = 7.07mm2
The maximum number of cables we can install ,
= space available for cables ---------------- space occupied by 1 cable
= 1125 ÷ 7.07 = 159.1
the maximum number of these cables we could install in a 50mm x 50mm trunking is ( 159 )

Remember that we always round down to the nearest whole number , never round up ←

Example :
A 75mm x 25mm trunking is installed and contains 26 x 2.5mm2 stranded cables and 20 x 4mm2 cables ,
We are to install some extra circuits which will total 12 x 1.5mm2 solid copper cables , does the trunking have enough capacity for these extra cables ?
Factors we require are :
75mm x 25mm = 738 ……… ( On-Site Guide table 5F .. p/122 )
2.5mm2 stranded cable = 12.6 ( On-Site Guide table 5F .. p/121)
4mm2 stranded cable = 16.6
1.5mm2 stranded cable = 8.0
Total factor for 2.5mm2 stranded cables ( 26 x factor = 26 x 12.6 = 327.6 ) 26 time 12.6 = 327.6
Total factor for 4.0mm2 cables ( 20 x factor = 20 x 16.6 = 332 )
Total factor for installed cables ( 327.6 + 332 = 659.6
Trunking factor for 75mm x 25mm = 738 ( 5F o/s/g
Factor available for extra cables :
Trunking factor – total factor for installed cables ( 738 sub 659.6 = 78.4 )
Factor for 1.5mm2 solid copper cable = 8.0
Number of extra cables we could install ( 78.4 ÷ 8.0 = 9.8 )
So we could install 9 extra cables ,
Therefore our trunking has got sufficient capacity to allow us to install 12 more , 1.5mm2 solid cables

↔ The provision of spare space is advisable , however , any circuits added at a later date must take into account grouping , Regulation 523.5 p- 103 regs

Live conductors: should be either insulated and protected against mechanical damage or placed and safeguarded, for example inside an earthed metal enclosure. This is to ensure that persons do not have access to them, when they are live or energised. Where necessary to prevent danger, the access door should be interlocked with the supply so that conductors are isolated and earthed before access is permitted.

Fuses: should be selected to be the minimum rating (but having taken into account the likelihood of them failing on,
for example, the surge current on starting up a motor)

Capacitors • Used to store electricity

 

[amberleaf]

Volts (V) A water dam with pipes coming out at different heights. The lower the pipe along the dam wall, the larger the water pressure, thus the higher the voltage :
Amps (A) A river of water. Objects connected in series are all on the same river, thus receive the same current. Objects . Connected in parallel make the main river branch into smaller rivers. These guys all have different currents.
Résistance : Ohm (Ω)
If current is analogous to a river, then resistance is the amount of rocks in the river. The bigger the resistance the less current that flows

Resistors in Series: All resistors are connected end to end. There is only one river, so they all receive the same current .
But since there is a voltage drop across each resistor , they may all have different voltages across them. The more resistors in series the more rocks in the river, so the less current that flows

Resistors in Parallel: All resistors are connected together at both ends. There are many rivers (i.e. The main river branches off into many other rivers), so all resistors receive different amounts of current .But since they are all connected to the same point at both ends they all receive the same voltage.

In alternating current (AC, also ac) the movement (or flow) of electric charge periodically reverses direction. An electric charge would for instance move forward, then backward, then forward, then backward, over and over again. In direct current (DC), the movement (or flow) of electric charge is only in one direction.

• Kilovolt: kV; One thousand volts.
• Kilovolt amperes: Kva; One thousand volt amps.
• Kilowatt: Kw; One thousand watts.
• Kilowatt Hour: Kwh; One thousand watt-hours.

DEFINITIONS & TERMINOLOGY

* Alternating Current: (AC); Electrical current that changes (or alternates) in magnitude and direction of the current at regular intervals.
* Amp: (ampere)The basic unit of current in an electrical circuit. One ampere is the rate of flow of electric current when one coulomb of charge flows past a point in the circuit in one second. Symbolically characterized by the letter "I" and sometimes "A" when used in formulas.
* Amplifier: An electrical circuit that increases the power, voltage or current of an applied signal.
* Anode: A positive (+) electrode. The point where electrons exit from a device to the external electric circuit.
* Break: The act of the opening of an electrical circuit.
* Bridge Rectifier: A full-wave rectifier where the diodes are connected in a bridge circuit. This allows the current to the load during both the positive and negative alternating of the supply voltage.
* Capacitor: A device used to store electrical energy in an electrostatic field until discharge.
* Cathode: A negative (-) electrode. The point of entry of electrons into a device from an external circuit. The negative electrode of a semiconductor diode.
* Celsiuses: A temperature scale. Also known as centigrade. Sea level water will freeze at 0°C and will boil at 100°C.
* Charge: The measured amount of electrical energy that represents the electrostatic forces between atomic particles. The nucleus of an atom has a positive charge (+) and the electrons have a negative charge(-).
* Circuit: A full path of electrical current from a voltage source that passes completely from one terminal of the voltage source to another.
* Conductance: The measure of the ability of a material or substance to carry electrical current.
* Conduction: The moving of electricity or heat through a conductor.
* Conductor: A material used to conduct electricity or heat.
* Coulomb: A unit of electric charge. The amount of charge conveyed in one second by one ampere.
* Current: The rate at which electricity flows, measured in amperes, 1 ampere = 1 coulomb per second.
* Cycle: or Hertz; The measurement of the time period of one alternating electric current. In the UK this is commonly 50 cycles per second, or 50 Hertz.
* Cycle Time: The time it takes for a controller to complete one on/off cycle.
* Delta: In a three phase connection all three phases are connected in series thus forming a closed circuit.
* Dilectric: Non-conducting material used to isolate and/or insulate energized electrical components.
* Diode: A device having two terminals and has a low resistance to electrical current in one direction and a high resistance in the other direction.
* Direct Current: (DC); Electrical current that flows consistently in one direction only.

• Efficiency: Output power divided by input power, (work performed in ratio to energy used to produce it).
• Electric circuit: An arrangement of any of various conductors through which electric current can flow from a supply current.
• Electricity: A form of energy produced by the flow of particles of matter and consists of commonly attractive positively (protons (+) and negatively (electrons (-) charged atomic particles. A stream of electrons, or an electric current.
• Electrochemistry: Chemical changes and energy produced by electric currents.
• Electrode: An anode (+) or cathode (-) conductor on a device through which an electric current passes.
• Electrodynamic: The interaction of magnetism and electrical current.
• Electrokinetics: The behaviour of charged particles and the steady motion of charge in magnetic and electric fields.
• Electrolysis: Electric current passing through an electrolyte which produces chemical changes in it.
• Electromagnet: A coil of wire wound about a magnetic material, such as iron, that produces a magnetic field when current flows through the wire.
• Electromagnetic field: Electric and magnetic force field that surrounds a moving electric charge.
• Electron: A fundamental negatively (-) charged atomic particle that rotates around a positively (+) charged nucleus of the atom.

• Farad: The unit for capacitance. A capacitor that stored one coulomb of charge with one volt across it will have a value of one farad.
• Field cell: Commonly used in generators and motors, it is an electromagnet formed from a coil of insulated wire that is wound around a soft iron core.
• Field-Effect Transistor (FET): A three terminal semiconductor device. In a "FET" the current is from source to drain because a conducting channel is formed by a voltage field between the gate and the source.
• Filament: The element inside a vacuum tube, incandescent lamp or other similar device.
• Filter: A circuit element or components that allows signals of certain frequencies to pass and blocks signals of other frequencies.
• Fluorescent: The quality of having the ability to emit light when struck by electrons or another form of radiation.
• Flux: The rate of transfer of energy.
• Frequency: Also known as Hertz, it is the number of complete cycles of periodic waveform that occur during a time period of one second.
• Ground: A reference point at zero potential with respect to the earth. In an electronic circuit it is the common return path for electric current. A conducting connection between the earth and an electrical circuit or electrical equipment. Also, the negative side of DC power supply.
• Hard Wired: That part of a circuit which is physically interconnected.
• Hazardous Location: An area in which combustible or flammable mixtures are or could be present.
• I: Intensity. The commonly used symbol used to represent Amperes when used in formulas. I = Intensity = Current = Amps = Amperes.
• Impedance: The opposition to electrical flow.
• Infrared: The form of radiation used to make non-contact temperature measurements. In the electromagnetic spectrum it is the area beyond red light from 760 nanometers to 1000 microns.
• Interface: The method by which two devices or systems are connected and interact with each other.
• Joule: The basic of thermal energy. The work done by the force of one newton acting through a distance of one meter.
• Lag: The time delay between the output signal and the response time of the receiver of the signal.
• Leakage current: A small current leaking from an output device in the off state caused by semiconductor characteristics.
• Light Emitting Diode: LED; A solid state light source component that emits light or invisible infrared radiation.
• Load: The electrical demand of a process. Load can be expressed or calculated as amps (current), ohms (resistance) or watts (power).

 

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• Farad: The unit for capacitance. A capacitor that stored one coulomb of charge with one volt across it will have a value of one farad.
• Field cell: Commonly used in generators and motors, it is an electromagnet formed from a coil of insulated wire that is wound around a soft iron core.
• M: Symbol for Mega, one million.
• Magnetic Field: A region of space that surrounds a moving electrical charge or a magnetic pole, in which the electrical charge or magnetic pole experiences a force that is above the electrostatic ones associated with particles at rest.
• Magnetic Flux: Expressed in webers, it is the product of the average normal component of the magnetic intensity over a surface and the area of that surface.
• Make: To close an electrical circuit. To establish an electrical circuit through the closing of a contact, switch or other related device.
• Manual Reset Switch: A switch in a controller that manually resets after exceeding the controllers limit.
• Maximum Load Current: see; "Maximum Power Rating".
• Maximum Operating Temperature: The maximum temperature at which a device can be safely operated.
• Maximum Power Rating: The maximum watts that a device can safely handle.
• Mean Temperature: The average temperature of a process.
• Microamp: One millionth of an amp.
• Micron: One millionth of a meter.
• Microvolt: One millionth of a volt.
• Mil: One thousandth of an inch.
• Milliamp: mA; One thousandth of an amp.
• Millimeter: mm; One thousandth of a meter.
• Millivolt: mV; One thousandth of a volt. The difference in potential needed to cause a current of one milliampere flow through a resistance of one ohm.
• Momentary switch: A switch with contacts that are made with actuating force and released when that force is removed.

• N.C.: Normally Closed.
• N.O.: Normally Open.
• Ohm: The unit by which electrical resistance is measured. One ohm is equal to the current of one ampere which will flow when a voltage of one volt is applied
• Ohmeter: A meter used to measure electrical resistance in units of ohms.
• On/Off Controller: A controller whose action is either fully on or off.
• Open Circuit: An electrical circuit that is not "made". Contacts, switches or similar devices are open and preventing the flow of current.
• Operating Temperature: The range of temperature over which a device may be safely used. The temperature range which the device has been designed to operate.
• Output: The energy delivered by a circuit or device. The electrical signal produced by the input to the transducer.
• Phase: The time based relationship between a reference and a periodic function.
• Polarity: Magnetically, opposite poles, north and south. In electricity, oppositely charged poles, positive and negative.
• Power Dissipation: The amount of power that is consumed and converted to heat.
• Power Supply: The part of a circuit that supplies power to the entire circuit or part of the circuit. Usually a separate unit that supplies power to a specific part of the circuit in a system.
• Pulse: A rise and fall of voltage, current, or other faction that would be constant under normal conditions. A pulse that is intentionally induced will have a finite duration time.
• Quantum: One of the very small discrete packets into which many forms of energy are subdivided.
• Quartz: A form of silicone dioxide. Commonly used in the making of radio transmitters and heat resistant products.
• Rectifier: A device that converts AC voltage to pulsating DC voltage.
• Relay: A Solid State relay is a switching device that completes or interrupts a circuit electrically and has no moving parts. A Mechanical relay is an electromechanical device that closes contacts to complete a circuit or opens contacts to interrupt a circuit.
• Resistance: The resistance to electrical current. Resistance is measured in ohms.
• Response Time: The amount of time it takes for a device to react to an input signal.
• Rheostat: A variable resistor.
• Ripple: A fluctuation in the intensity of a steady current.
• Root Mean Square: RMS; AC voltage that equals DC voltage that will do the same amount of work. For an AC sine wave it is 0.707 x peak voltage.

• SCR: Silicone Controlled Rectifier.
• Series Circuit: A circuit which may have one or many resistors and/or other various devices connected in a series so that the current has only one path to follow.
• Supply Current: Current Consumption. The amount of amps or milliamps needed to maintain operation of a control or device.
• Supply Voltage: The range of voltage needed to maintain operation of a control or device.
• System International: SI; The standard metric system of units.
• Transducer: A device that transfers power or energy from one system to another, such as taking a physical quality and changing it to an electrical signal.
• Transient: A sudden and unwanted increase or decrease of supply voltage or current.
• Thermistor: An electrical resistor composed of semiconductor material, whose resistance is a known rapidly varying function of temperature.
• Transient: A sudden and unwanted increase or decrease of supply voltage or current.

• Triac: A solid-state switching device used in switching AC wave forms.

• UHF: Ultra High Frequency

• Vacuum: Pressure that is less than atmospheric pressure.
• VF: Variable Frequency.
• VHF: Very High Frequency.
• Volt: Voltage; The unit of electromotive force (EMF) that causes current to flow. One volt causes a current of one amp through a resistance of one ohm.
• Voltage Drop: The difference in potential measured between two points caused by resistance or impedance.
• Voltmeter: A meter used to measure units of volts.
• Watt: The unit of power. One watt equals one joule per second, 1/746th horsepower.
• Watt-hour: The power of one watt operating for one hour, and equal to 3,600 joules.
• Weber: The standard unit of magnetic flux.

• Zener Diode: A silicone semiconductor that maintains a fixed voltage in a circuit.