Re-take - Useful Information for 2394 :

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ELECTRICAL INSTALLATION CERTIFICATE GUIDANCE FOR RECIPIENTS
ThisCertificate is intended to be issued only for a Newelectrical installation or for new work associated with an addition or alteration to an existing installation. It should not have been issuedfor the inspection of an existing electrical installation .


Reminder. An " Electrical Installation ConditionReport " should be issued for such an inspection. Existing electrical installation ◄► ( -&-s ) Q/As

Sorry about that . it sometime scrabbles it

 

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Useful- Junk . RCDs

Taken from 16[SUP]th[/SUP] Edition . 2005 . ◄

Tests are made on the load-side of the RCD between the Line-conductor of theprotected-circuit & the associated CPC . Any load or appliances should be disconnected prior to Testing .

RCD test-instruments require a few-milliamperes to operate . mA .
This is normally obtained from the Line & Neutral of the circuit-under-test . When testing a Three-phase RCD protecting a Three-wire-circuit . the instrument’s- neutral is required to be connected to Earth .

This means that the test-current will be increased by the instrument-supply-current & will cause some-devices to operate during the (50% - Test ) possibly indicating an incorrect-operating-time . Under this circumstances it is necessary to check the operating-parameters of the RCD with the Manufacture before failing the RCD .

RCD - Tester/instrument is an electronic-device which draws current from the supply for its Operation .

Three-wire / Three-phase-system . ( there is No-Neutral with the supply ) is being tested .
The tester must be connected to a Neutral-conductor to provide the power it need for Operation . Thus
Operating-current will flow through a Line-conductor and return through the Neutral . giving a basic-imbalance .

Testing RCDs

The RCD -instrument is connected to the device to be tested by plugging it into a suitable-outlet . 2392-10. this is all you require

Or - by connecting to the , Line & Neutral-conductor .

► We still have Test-instrument , with 2 - leads , & 3 - leads in use .

 

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Re-cap : GN-3 .p/66

Requirements for Inspection & Testing .

Firstly : 3.8.1. Scope
The purpose of periodic-inspection andtesting is to provide an ( Engineering-view) on whether or not the installation is in a satisfactory-condition where it can continue to beused in a Safe-Way .

3.8.2. Process -Prior to carrying out Inspection & Testing

Prior to carrying out the Inspection , ( The Inspector ) will need to meet with the client or the client’s representative to outline the ( Scope) and nature of the work required and to highlight likely-items that require-isolation. refer GN-3

 

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Periodic-Inspection Basic

All electrical-installation deteriorate with age & use . They should therefore be , Inspected & Tested at appropriate-intervals to check whether they in a satisfactory-condition for continued-service

As GN-3 , reminds us . Safety-Checks . referred to as , Periodic-Inspection & Testing .

 

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How can Iavoid Accidents involving Underground-Services.

Health & Safety Executive’s publication . HSG - 47 . avoiding danger from Underground-Services.

Which can be downloaded free of charge . from the HSE website
[h=3]Avoidingdanger from underground services - HSG47 - HSE[/h]www.hse.gov.uk/pubns/books/hsg47.htm

 

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Re-cap

O.S.G. p/110 Table - A1

Fluorescent or Discharge lighting is involved.
A factor of ( 1.8 ) is used to take into consideration the associated-control-gear.

Scenario: 80W / 230V Fluorescent-fitting will have a current-rating of . 80 x 1.8 / 230 = 0.63A . 0626086956 - rounded up to 0.63A

O.S.G. p/110 Notes - 2 .
Final-circuits for Discharge lighting must be arranged so as to be capable of carrying the total-steady-current . viz that of the lamp(s) and any associated-controlgear and also their harmonic-currents .

Where more exact-information is not-available . the demand in volt-amperes is taken as the rate-lamp-watts , multiplied by not less than ( 1.8 )

This multiplier is based upon the assumption that the circuit is corrected to apower-factor of not less than ( 0.85 lagging ) and takes into account controlgear losses and harmonic-currents .

 

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Conduit:

A Conduit is a tube or pipe , in which conductors are run . in effect . the Conduit replaces the PVC-sheathing of the cable .
Providing - mechanical-protection . for the insulated-conductors .

As the Regulations , remind us

Thereare three-types of Conduit.
Metal
Flexible- metal … ( High-electrical-resistance )
Non-metallic ( PVC )

Non-metallic ( PVC )
(PVC ) conduit is being increasingly used in place of metal-gauge-steel-conduit. more easily installed than steel-conduit & that it is Non-corrosive & unreactive with nearly all chemicals

Metal-Conduit: Corrosion-resistance in damp situations .

Some facts : Plastic-conduit . is made of an Insulating-material . [ it does not provide a means of earth-continuity ]

Conduit:
Galvanized: Protection from corrosion by a specified-coating of Zinc . Electro-galvanized-method .

Metal- “ Ferrous-metal “

□ Protection against Mechanical-Damage
The word ( Mechanical ) is somewhat misleading . in that most of us associate it with machinery of some sort .

16[SUP]th[/SUP] Edition . 522-08-01. ◄
Conduit: Terminations and Junctions
Ends shall be free from Burrs . Terminations in equipment not fitted with spout-entries shall be treated to prevent-damage to the cables .
( A female-bush on the end of the conduit is a suitable-means of achieving this ) Conduit locking-nut Brass-bush female

16[SUP]th[/SUP] Edition . 522-12-01. ◄
Long-straight-lengths of rigid-plastic-conduit must allow for ( Expansion and contraction ) slip-joints in plastic-conduit is a means of achieving this .

16[SUP]th[/SUP] Edition . 527-02-01. ◄ Fire-barriers
Where conduit pass through floors . walls .partitions or roofs . the opening through such walls or floors . Etc shall be sealed to the same-degree of fire-résistance as that of the material through which it is passing .

16[SUP]th[/SUP] Edition . 527-02-01. ◄ Fire-barriers
Where a wiring-system passes through elements of building-construction such as floors . walls . roofs .ceiling . partitions . cavity-barriers .the openings remaining after passage of the wiring-system shall besealed according to the degree of fire-résistance ( if any )

17[SUP]th[/SUP] Edition . 527.2.1. ◄ Fire-barriers p/132
Where a wiring-system passes through elements of building-construction such as floors . walls . roofs .ceiling . partitions . cavity-barriers .the openings remaining after passage of the wiring-system shall besealed according to the degree of fire-résistance ( if any ) prescribed for the respective-element of building-construction before penetration .

16[SUP]th[/SUP] Edition . 522-08 . ◄
Other mechanical stresses ( AJ )
522-08-01 .
A wiring-system shall be selected and erected so asto minimize during-installation . use and maintenance , damage to the ( Sheath and Insulation of cables and insulated-conductors and their-terminations )

527.2. Sealing of wiring system-penetrations

17[SUP]th[/SUP] Edition . 527.2.1. ◄
522.8.1.
A wiring-system shall be selected and erected to avoid during-installations . use or maintenance . damage to the ( Sheath and Insulation of cables and their terminations ) Note here : The use of any lubricants that can have a detrimental-effect on the cable or wiring-system are not-permitted .

16[SUP]th[/SUP] Edition . 543-02-07◄
Where the protective-conductor isformed by metal-conduit . trunking or ducting or the metal-sheath and / or armour of a cable . the earthing-terminal ofeach-accessory shall be connected by a separate-protective-conductor to n earthing-terminal incorporated in the associated-box or other-enclosure .

17[SUP]th[/SUP] Edition . 543.2.7. ◄
Where the protective-conductor isformed by metal-conduit . trunking or ducting or the metal-sheath and / or armour of a cable . the earthing-terminal ofeach-accessory shall be connected by a separate-protective-conductor to n earthing-terminal incorporated in the associated-box or other-enclosure .

Regulation - 543.2. Types of protective-conductors . ( Wording here is ) Types
543.2.1. ( vi ) Metal-conduit )

 

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2011: JIB. Extracts . What is an Electrician
Qualification & Assessment procedures that have been developed by the Industry

THERE IS OFTEN confusion over what anelectrician is and what qualifications someone working on electrical systems shouldhave. However, the electrical industry has recognised formal qualificationsthat provide a clear qualification route for an electrician. Standards forelectrotechnical qualifications have been defined through industry consultationby government agencies for many years.

The industry expects alloperatives that are working unsupervised in the electrotechnical sector to bequalified to the industry-recognised NVQ level 3 qualification. The JointIndustry Board (JIB) recognises these standards in the ElectrotechnicalCertification Scheme

(ECS). To qualify for theECS card as an electrician, a relevant industry level 3 qualification (orrecognised equivalent for pre-NVQ) is required which includes the necessaryunderpinning knowledge and competency assessment. For all new entrants tobecome recognised as an electrician the Level 3 NVQ Diploma in Installing Electrotechnicalsystems and equipment (building structures and the environment) is required. Alternatively,it may be possible to meet the ECS card requirements with the level 3 NVQ inElectrotechnical Services ( ElectricalInstallation – Buildings & Structures ) with the necessary underpinningknowledge qualification ( or technical certificate ) at level 3 and the AM2assessment. Individuals who have some previous experience need an interviewwith an assessor to develop an individual assessment plan without the need togo back to college to train in the classroom.

This is in line with thenormal industry qualification requirements, and only focuses on the requiredpart of the assessment. The value of this is that the competence the individualhas already achieved is credited toward achieving the full industryqualification.

Qualifications such as the standalone17th Edition of the IET Wiring Regulations, the Certificate in Fundamental Inspectionand the Certificate in the Certification of Electrical Installations ( inspection, testing and certification of electricalinstallations ) are designed as professional development for qualified electricians,and, as such, are unsuitable for unqualified personnel or new entrants into theindustry. On their own they do not demonstrate the industry-required qualificationand competence needed to be recognised as an electrician.

Any reference to Part P ofthe building regulations is for a company to comply with the legislativerequirement ( within Englandand Wales) and is not a general requirement for individually qualified electriciansemployed within the industry. Short ‘ PartP ’ training programmes are only for individuals who have been working withinthe industry for at least two years and wish to be registered as a QualifiedSupervisor for their company. These courses do not qualify individuals aselectricians because the training is focused on the requirements of theBuilding Regulations.

Operatives who are alreadyformally qualified to the NVQ Level 3 do not need to re-qualify if they are theproposed Qualified Supervisor for their company, but will need to demonstrate theirknowledge of the Building Regulations during their company’s Part - Passessment visit by the relevant

Competent Persons Schemeprovider. The future training requirements of the industry remain much the sameas they were when the electrical apprenticeship was first introduced.

Electricians still need agood grounding in electrical theory, which will provide the basis ofintegrating new and emerging technologies into electrical installations.

Electricians also continueto need a full working knowledge of the wiring regulations in order to ensurethat their work meets the required British Standards and is safe in itsoperation.

The JIB has supportedapprentice training from its inception in 1968 and some 160,000 installationelectricians have been trained under JIB Apprentice Training Schemes. Thisrepresents a tremendous achievement by the JIB and the electrical industry interms of the people who were trained, the companies who employed them and UK plcin terms of their real contribution to the economy over the years.

The best way to train newentrants into the electrical industry is through a formal industryapprenticeship, but formal industry apprenticeship, but there are alsoopportunities for people to prove their competence through site assessment.

The JIB has a long historyof accrediting the formal qualifications held by professional electricians throughthe ECS card. Anyone who holds an ECS can easily demonstrate that he or she has met the requirements to truly becalled an electrician

 

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Rewireablefuse (Cf) . PS still in the Regulations BS-2011: :icon_bs:

Those fusesreferred to as ‘rewirable fuses’ are correctly termed semi-enclosed fuses(complying with BS-3036) as they are partially enclosed within thefuse-carrier. Regulation - 533.1.1.3 of Amendment 1 of BS-7671:2008 states that a fuse shall preferablybe of the cartridge type ( but this does not preclude the use and installation of semi-enclosed fuses ).

The regulationstates that where a semi-enclosed fuse is selected, it shall be fitted with anelement in accordance with the manufacturer’sinstructions, if any. In the absence of such instructions, it shall be fittedwith a ( Single element of tinned copper wire of theappropriate diameter specified in Table 53.1. )

The size neededfor a conductor protected against overload by a BS-3036 semi-enclosed fuse can be obtained by theuse of a rating factor, ( 1.45 / 2 = 0.725) which results in the same degree of protectionas that afforded by other overload protective devices.

 

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Circuit breaker(s)

Contacts with in the conventional time. This isdefined as ( One or Twohours ) ( 1.45In relates directly to circuit design ) in section 433 protection against overload-current , regulation - 433.1.1 States that:
“ the operating characteristics of a device protecting a conductor against overload shall satisfy the following conditions :

(i) the rated current or current setting of the protective device ( In ) is not less than the design current (Ib) of the circuit , &
(ii) the rated current or current setting of the protective device (In) does not exceed the lowest of the current-carrying-capacities (Iz) of any of the conductors of the circuit , &
(iii) the current (I2) causing effective operation of the protective device does not exceed 1.45 times the lowest current carrying capacities (Iz) of any of the conductors of the circuit. ”

The factor 1.45 ensures that deterioration of cables does not result from small overloads.

When a current of 1.45 times the current carrying capacity of the cable is interrupted within the conventional times , there is nosignificant deterioration in the working life of the cable.

 

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Magnetic-characteristic . Circuit-breaker(s)

letter B , C , or D , represents a multiple of ( In ) When the current rises to thismultiple value , the magnetic operates instantaneously to open the trip operates instantaneously to open the contacts.

 

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Re-cap.

Firstly - ( Protective-devices in question ) The Regulations have stated the Facts .

533. p/139 . Devices for protection against Overcurrent :

533.1. General-requirements .
A device for protection against Overcurrent shall comply with one or more of thefollowing :

• BS-88 : Series
Appendix - 1 . p/277 . ( Normative)
BS-88: The term “ BS-88 : Series “ . when used in these Regulations . ( Means ) BS-88-1 , - 2 , - 3 .

• BS-646
Appendix - 1 . p/277 . ( Normative)
BS-646:1958 ( 1991 ) Specification .Cartridge-fuse-links . ( rated upto 5 amperes ) for a.c. & d.c. service .
BS-646: remains-current but the requirements for . type - B . fuse-links have been replaced by . BS-2950:1958

• BS-1362
Appendix - 1 . p/278 . ( Normative)
BS-1362: 1973 ( 1992 ) Specification for general-purpose-fuse-links for (Domestic & similar purposes ) Primarily - for use in plugs.

• BS-3036
Appendix - 1 . p/278 . ( Normative)
BS-3036: 1958 ( 1992 ) Specification . Semi-enclosed-electric-fuses. ( ratings up to 100- amperes & 240V to Earth .

• BS-EN-60898-1 . & - 2
Appendix - 1 . p/285 . ( Normative)
BS-EN-60898: 1991 . Specification . for circuit-breakers for overcurrent-protection for ( Household & similar installations ) Replaced by BS-EN-60898-1 : 2003 : but remains-current .

Appendix - 1 . p/286 . ( Normative)
BS-EN-60898-1: 2003 . Circuit-breakers for a.c. - operation .

Appendix - 1 . p/286 .
BS-EN-60898-2: 2001 : Circuit-breakers for a.c. & d.c. . operation
BS-EN-60898-2: 2001 . remains-current . ( It was withdrawn in error & has been reinstated )

• BS-EN-60947-2 . & - 3
Appendix - 1 . p/286 . ( Normative)
BS-EN-60947-2: 2006 . Circuit-breakers .

• BS-EN-60947-4-1 , - 6-1 & - 6-2
Appendix - 1 . p/286 . ( Normative)
BS-EN-60947-4-1: 2001 ; 2001 . Contactors & motor-starters - Electromechanical-contactor & motor-starters .

• BS-EN-61009-1 .
Appendix - 1 . p/287 . ( Normative)
Electrical-accessories.
Residual-current-operated, circuit-breakers with , integral-overcurrent-protection for (Household & similar uses ) RCBOs . General-rules . ( Making me Part-1 )

 

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Still some confusion with (IP - Codes ) in the Regulations’

The Regulation’s , have stated the facts . :svengo:
Note :
( Barrier or Enclosures ) are intended to prevent-contact with ( Live-parts ) Hand’s & finger’s

Barriers or enclosures . 416.2.

IPXXB :- denotes protection against - finger-contact-only
IPXXD :- denotes protection against - penetration by 1mm diameter-wires-only

IPXXB - IP2X
IPXXD - IP4X

X - Indicates no specified-protection .

First-numeral , Mechanical-protection .
Second-numeral . Liquid-protection .

The most commonly-quoted ( IP -Codes ) in the , 17[SUP]th[/SUP] Edition - 2008:2011:
IPXXB - IP2X
IPXXD - IP4X

2 ) Protection against ingress of large-solid-foreign-bodies .
- Protection against contact with live or moving-parts ( Inside the enclosure ) by fingers
- Protection against ingress of medium-size-solid-foreign-bodies

4 ) Protection against contact with live or moving-parts ( Inside the enclosure ) by Tools . wires or such objects of thickness greater than ( 1mm )
- Protection against ingress of small-solid-foreign-bodies

416.2.2. p/67 .
A ( horizontal-top surface ) Top of Consumer-unit . or enclosure which is readily-accessible , shall provide a degree of protection of at least IPXXD - IP4X

416.2.3.
A ( Barrier or enclosure be firmly secured in place ) & have sufficient-stability & durability to maintain the required-degree of protection . Etc

416.2.4. Where it is necessary to remove a ( Barrier or open an enclosure) or remove-parts of enclosure(s) , this shall be possibly-only

Your three-main-points , here .

- By the use of a key or Tool

► Safe-Isolation . re-cap

- After disconnection of the supply to live-parts , which the ( Barrier or enclosures afford protection )

- Restoration of the supply being-possible-only after replacement or reclosure of the ( Barrier or enclosures )

- Where an ( Intermediate-barrier providing a degree of protection ) of at least , IPXXB or IP2X prevents-contact with live-parts .

2392-10 / 2394 : By the use of a ( Key or Tool ) to remove the intermediate-barrier . ( Screwdriver )

Gentlemen:
Point to Note here . All it takes is little-pressure to hit (The Button ) THANK -YOU .
Even Amber has to go through BOOKS . GN-3 , 17[SUP]th[/SUP] Edition , O.S.G. & type up

 

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Inspection . Testing & Certification .

Two-types.

Initial-Verification. 2392-10
Is required for New-Work . & (Alterations & Additions )

Periodic-Inspection & Testing
Is required for ( Existing-installations ) & Initial-Verification. 2395

Regs. p/36 .
Verification :
All measures by means of which compliance of the electrical-installation with the relevant-requirements of BS-7671: are checked , comprising
Inspection
Testing
Certification

 

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2392-10. re-cap Appendix - 15 ( Informative) :icon_bs:
p/425- Ring & Radial-final-circuit .

Ring-final-circuit-arrangements. Regulation - 433.1.103 . p/81.

The load-current in any part of thecircuit should be unlikely to exceed for long-periods the current-carrying-capacity of the cable .

433.1.103. This can generally be achieved by :
i) Locating socket-outlets to provide reasonable-sharing of the load around the ring .

the only-mention of this is in Appendix - 15 . (ii) p/425 … comply with Regulation - 433.1.103
ii) Not supplying ( Immersion-heaters) comprehensive ( Space-heating ) or loads of a similar-profile from the ring-circuit .

iv) Taking account of the ( Floor-area ) being served . a limit of 100m[SUP]2[/SUP] has been-adopted . Etc

O.S.G.. p/177 H5 . re-cap
Water & Space-heating

Water-heaters fitted to storage-vessels to excess of ( 15- litres-capacity ) or permanently-connected-heating-appliances forming part of a comprehensive , Space-heating-installation ,should be supplied by their own-separate-circuit.

( Immersion-heaters ) 16A - circuit-breaker . & a 20A DP - switch .


Comment in ( GN-1 ) is ( Immersion heaters ) should Not be connected using a plug and socket-outlet , but a switched-cord-outlet-connection-unit complying with BS-1363-4 .

BS-1363-4. p/278 .
BS-1363-4: 1995 . Specification . for 13A fused-connection-units , switched & unswitched .

559.6.1.1. p/177. Connection to the fixed-wiring .
(vii) A connection -unit to BS-1363-4 . … 13A fused-connection-unit . We have the 16[SUP]th[/SUP] Edition . still out there .

Refer . Appendix - 15 fig 15B . p/426 .
Table 53.4.


Origin of an Installation : p/31
The position at which electrical-energy is delivered to an electrical-installation. 2392-10

 

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Corrigendum - 2011

Smart meters and dumb fires

Smartmeter rollout
Oneadvantage of smart meters is that the suppliers will no longer have to employan army of people to knock on doors to physically inspect meters and ensurethat readings are accurate and no unauthorised tampering has taken place.
However,the supplier will need to mobilise legions of smart-meter installers. Most havereached the logical conclusion that they ought to retrain some of theirexisting meter operators, inspectors and readers. They are also advertising job vacancies specifying no experiencenecessary since you do not have to be a qualified electrician to replace anexisting meter with a smart one.
Extracts :
Othershave voiced concerns about the safety of the work being carried out. TheElectrical Safety Council (ESC), whose recommendations are supported by a rangeof industry bodies, wants an isolating switch built into smart meters. Thiswould allow contractors a simple and safe means of isolating the electricitysupply in UKhomes when necessary, such as for the replacement of a consumer unit.
Theonly way currently to isolate the supply is to remove the electricitydistributor's cut-out fuse but electricians are not authorised to do this. TheESC claims that efforts to provide such permission have been blocked by theelectricity supply industry.
Extracts :
Despitebeing unauthorised, many electrical contractors remove cut-out fuses whennecessary, as the legitimate alternatives cost time and money for bothcontractors' businesses and their clients, says the ESC.
Asan added safety measure, smart meters are being designed to give a ( last gasp' alarm signalif the supply to the meter is cut ) Thiswill immediately alert the authorities toany unauthorised removal of a cut-out fuse. ◄◄

http://eandt.----------/magazi...y-of-our-own-homes.cfm


Question, how many training hours will beavailable to bring a ' Non-experienced ' person up to a ( Competent - Standard ?)

 

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2392-10 .

Earth-fault-loop-impedance: ( Circuit-loop-impedance )

All necessary safety-precautions must be taken . With any Testing .

This test has to be carried out on an Energized-installation.

The purpose of this test is to ensure that , in the event of a Line-to-Earth-fault.

Circuit-breaker: Enough-current will flow around the Earth-fault-loop-path . to operate the protection within a specified-time .

• The measured-value of loop-impedance is then compared with that given in the Regulations .

GN-3. p/83 . Earth-fault-loop-impedance-tester .. BS-EN-61557-3 .

This Instrument-functions by creating . an Earth-fault .
2392-10 : is connected to the circuit via a plug . in your case Only.
Or
By “ Flying-leads “ connected-separately to Line , Neutral , Earth .

p/84 . RCD Tester(s) BS-EN-61557-6
2392-10 : is connected to the circuit via a plug . in your case Only .
Or
By “ Flying-leads “ are need for Non-socket-outlets-circuit(s) that’s why you have , Three-leads on your Test-instrument . for Use OFF

 

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NewMicrosoft Words .
Microsoft Words 2003 .does not leave a double-cap when typing. scrambles it together . on down load to the forum
Notethatthe “ O.S.G. “ does not express any preference between ring-final or radial-circuit(s) Both circuits areavailable to designers for use on their systems as they see fit .
O.S.G. Table – H2.1 . p/174 . Ring / Radialcircuit(s) A1 , A2 , A3 .
Designer to develop final-circuit(s)covering different floor areas and using different ratings of protectivedevices if he determine that the current drawn by devices connected to thecircuit and the diversity in use between the devices would allow different circuitarrangements to be used
O.S.G. is a handbookthat contains information not in BS-2008:2011: O.S.G. remindsus . it is a meant as a handy notebook reference for Electricians . working on building sites

 

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p/174 . Plugs and Socket-outlets. PS just some facts .


Regulation 553.1.100 states: “ Everysocket-outlet for household and similar use shall be of the shuttered type and , foran a.c. installation , shall preferablybe of a type complying with BS 1363. ”


Socket-outlets in excess of 13A, e.g.
Industrial types to BS EN 60309-2, are industrialtypes to BS EN 60309-2, are available in current ratings of 16 , 32 , 63 , 125A, but are not intended for household orsimilar use. Generally, these socket-outlets do not incorporate an integralshutter system.

 

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Useful – Junk : Where did the “ Word “ ring-circuit come from . ????


The start of the “ Ring-final-circuit “


Post War Building Study No 11 .


“ Electrical-installations “ waspublshed in . 1944 Section 76 gavebirth to the “ Ring-final-circuit “


We recommend thatsmall-dwellings of the types considered should be wired with three-seprate-circuits for lighitng , cooking , & socket-outlets respectively , each controlled by a separate single-pole-fuse , it is proposed that all socket-outletsshould be supplied from a “ Ring-final-circuit “ which , starting and ending at the fuse-terminal at the consumer.s supply control will pass through each room in turn .in the small dwellings under consideration it is considered permissible to connect up to 20 of the proposed standed-socket-outlets onthe “ Ring-circuit “ At theconsumer.s supply control the “ Ring-circuit “ willbe fused for 30 Amperes , a currentwhich is unlikely to be exceeded in the conditions of ( Load-diversity ) metwith in small-dwellings , At each outlet position on the “ Ring-circuit “ itwill be necessary to provide , a cartrigde-type-fuse for local-protection With regards to the socket-outlet-circuit ,the recommendation to connect a number of standard-socket-outlets on a “ Ring-circuit “ represents a departure from existing practice as laid-down in the wiring-regulation ( Eleventh-Edition )


With “ Ring-circuits “ rated at 30A and up to twenty-socket-outlets connected to the circuit , it was therefore necessary to incorporate a fuse on the ( Appliance-sideof the Electrical-system ) this led to the deveopment of “ British-Standard “ 1363:1947 . Fused-plugs & Shuttered-socket-outlets , Introduced in 1947.

 

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No- Socket Covers are in sight .


- - - Updated - - -

Just some Facts . Shutter – Mechanism :

BS-1363 :
Accessories to BS-1363are made to exacting requirements so that the plug perfectly fits thesocket-outlet . when BS-1363 was definedin the 1940s the designers wanted to make sure that the socket-outletwas verysafe , The standard requires that an interlocking shutter suystem stop randomobjects from being inserted into the socket-outlet(s) be inserted a distanceof 9.6mm into the socket before it makescontact with any live parts , the shutter system will operate and open toexpose the Line & Neutral-connections only when a plug is inserted .


It is Actioned by :
- The earth pin of the plug
- Both the Line & Neutral pinssimultaneously
- All three pins ; first the Earth pin follwed by both the Line & Neutralpins simultaneously

BS-1363: Therefore , already incorporates a mechanisum which stops intentional andunintentional . Direct contact with ,Live parts
Shutter –Mechanism : ( Under Nornal-Conditiond ) Shutter – Open . Earth pin present .
Shutter– Closed . No Earth pin inserted .


British 13 Amp sockets have built in automaticshutters to protect against children poking things in.


UK law requires all sockets sold to conform to the current BS-1363 standard , this is what ensures yourchild’s safety.
It was originally introduced in 1947 as:British Standard 1363 : 1947 FUSED PLUGSAND SHUTTERED SOCKET OUTLETS.


Regulation 553.1.100 States: “ Every socket-outlet for household and similar useshall be of the shuttered type and , for an a.c. installation, shall preferably shall preferably be of a typecomplying with BS 1363. ”


Plug pin dimensions in BS-1363-1.
BS-1363-2 socket-outlets due to the fact that protectionagainst access to the live and neutral socket contacts is always provided bythe shutters.

 

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BS-7671:2008:2011: have stated theFacts . Requirements for Testing : 2392-10 /2394 . The Sequence of (Tests ) Regulation – 612 . p/190 . Lists the sequence in which ( Tests ) should be carried out . Colum – 5 .under 612.1. Note : if any ( Test ) indicates a failure to comply .That test and any preceding-test . the results of which may have beeninfluenced by the fault indicted , shall be repeated after the fault has beenrectified . BS-7671:2008:2011: have stated theFacts . 612.2 / 13 . Initial-tests should be carried out in thefollowing-sequence where applicable , before the supply is connected or withthe supply disconnected as appropriate .

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BS-7671:2008:2011: have stated theFacts .

Requirements for Testing : 2392-10 / 2394 .

TheSequence of ( Tests )
Regulation– 612 . p/190 . Lists the sequence in which ( Tests ) should be carried out .

Colum– 5 . under 612.1.
Note : if any ( Test )indicates a failure to comply . That test and any preceding-test . the resultsof which may have been influenced by the fault indicted , shall be repeatedafter the fault has been rectified .

BS-7671:2008:2011: have stated theFacts . 612.2 / 13 .
Initial-testsshould be carried out in the following-sequence where applicable , before thesupply is connected or with the supply disconnected as appropriate .

 

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Inadequate testing of the power circuit , by relying solely on theuse of a voltage tester, commonly known as a ‘ Volt-stick ’ :13: Test before you touch – prove and verify the supply is de-energised by using appropriatetest methods and approved testinstruments, to test for the absence of voltage on ( All conductors ) including the Neutral-conductor ‘Volt-stick’ Thesetypes of testers must ( Not be relied upon ) toprove isolation in all circumstances.
Do We . !!
When ( Voltage testers ) are used to prove de-energisation, they must betested for correct operations immediately before use, and again immediatelyafter use – particularly if the test result indicates zero voltage – to confirmthat the instrument is still working correctly. :6:

 

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Useful-junk TheTerms .Exposed-conducting-parts & Extraneous-conducting-partswere first introduced into the 15[SUP]th[/SUP]Edition of the IEE Wiring Regulations Note: also that the current through the body is detrrmined notby the . RCD – sensitivity but by the , Voltage & Circuit-resistancee. Body-resistance RCDrated at 30mA will provide degree of protection . ( Additional ) ------ specify the use of . 30mA RCDs in most instances to give enhanced safety . The 15Edition required these to tripin . 40mS or less with a leakage-current of . 250mA Whereasthe 16[SUP]th[/SUP]Edition stipulates that the device should trip within . 40mS at aleakage of 150mA

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Useful-junk

The Terms . Exposed-conducting-parts& Extraneous-conducting-parts werefirst introduced into the 15[SUP]th[/SUP]Edition of the IEE Wiring Regulations

Note : also that thecurrent through the body is detrrmined not by the . RCD – sensitivity butby the , Voltage & Circuit-resistancee . Body-resistance

RCD rated at 30mA willprovide degree of protection . ( Additional)
The IET specify the useof . 30mA RCDs in most instances to give enhanced safety .

The 15Edition required these to tripin . 40mS or less with a leakage-current of . 250mA

Whereas the 16[SUP]th[/SUP]Edition stipulates that the device should trip within . 40mS at aleakage of 150mA

 

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As Electricians, Have you ever beenAsked ??? ( 1000 – times ) Why doRCDs sometimes trip Unnecessarily
Residual current devices (RCDs ) are usedextensively in installation to provide (Fault-protection ) & ( Additional-protection ) againstelectric-shock
Since the introduction of the 17[SUP]th[/SUP]Edition of the IET Wiring Regulations most, if not all final circuits in a newor re-wired installation in domestic premises to be provided with , ( Additional-protection by an RCD ),having a rated residual operating current ( I∆n ) of 30mA and an operating timenot exceeding 40mS , at 5 I∆n
While RCDs provide an ( Enhanced Level ) ofShock-protection, precautions should be taken to avoid , Unwanted-tripping ofthe devices on healthy circuits, Repeated unwanted tripping is likely to damageuser confidence in RCDs, and has been known to result in them being bypassed byfrustrated consumers.
Unwanted tripping of RCDs can be caused bythe current that may flow in the protective-conductor of circuit supplying certainitems of Class-1 earthed-equipment during their normal operation, Such items includeequipment-incorporating :
• Electrical noise – ( radio-frequency ) suppression filters, such aspersonal computers’, hi-fi equipment, TVs, DVDs, & the like .
• Heating-elements, such ascookers, water-heaters or radiant-heaters Etc .
• Motors, such as fridges &Freezers ( Common )
To avoid unwanted-tripping, RCDs shouldbe so selected and circuits so subdivided that any protective-conductor currentexpected to occur during normal operation of the Load(s) will be unlikely tocause tripping of the device.
Facts :That product standards permit certain equipment, such as personal computer’s tocreate up to 3mA of leakage currentin the protective-conductor
In order to minimise the risk ofunwanted tripping of RCDs, the number of items of protective-conductor-currentgenerating equipment per circuit, and the number of circuits’ served by eachRCD, need to be sufficiently small .
Tripping of an RCD may result if thetotal protective-conductor-current in the circuit(s) it serves exceeds ( 50% )of it’s rated residual operating current, that is ( 15mA for a 30mA device )

 

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Can some one advise me on M/Soft words 2007? Please. it has is spacing’s . and onAuto . what am I doing wrong .

 

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As Electricians, Haveyou ever been Asked ??? ( 1000 – times ) Why doRCDs sometimes trip Unnecessarily Residual currentdevices (RCDs ) are used extensively in installation to provide ( Fault-protection) & ( Additional-protection ) againstelectric-shock Since the introductionof the 17[SUP]th[/SUP] Edition of the IET Wiring Regulations most, if not all finalcircuits in a new or re-wired installation in domestic premises to be providedwith , ( Additional-protection by anRCD ), having a rated residual operating current ( I∆n ) of 30mA and anoperating time not exceeding 40mS , at 5I∆n WhileRCDs provide an ( Enhanced Level) of Shock-protection, precautions should be taken to avoid , Unwanted-trippingof the devices on healthy circuits, Repeated unwanted tripping is likely todamage user confidence in RCDs, and has been known to result in them beingbypassed by frustrated consumers. Unwanted tripping ofRCDs can be caused by the current that may flow in the protective-conductor ofcircuit supplying certain items of Class-1 earthed-equipment during theirnormal operation, Such items include equipment-incorporating : • Electrical noise – ( radio-frequency ) suppressionfilters, such as personal computers’, hi-fi equipment, TVs, DVDs, & thelike .• Heating-elements,such as cookers, water-heaters or radiant-heaters Etc .• Motors,such as fridges & Freezers ( Common) To avoid unwanted-tripping,RCDs should be so selected and circuits so subdivided that anyprotective-conductor current expected to occur during normal operation of theLoad(s) will be unlikely to cause tripping of the device. Facts :That product standards permit certain equipment, such as personal computer’s tocreate up to 3mA of leakage currentin the protective-conductor In order to minimisethe risk of unwanted tripping of RCDs, the number of items ofprotective-conductor-current generating equipment per circuit, and the numberof circuits’ served by each RCD, need to be sufficiently small . Tripping of an RCD mayresult if the total protective-conductor-current in the circuit(s) it servesexceeds ( 50% ) of it’s rated residual operating current, that is ( 15mA for a30mA device )

 

[amjed]

hye i try to make my first 6 post sorry ..

 

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Re-cap : 2392-10.
Final-circuits ( As the Duty Holder ) Consumer-unit(s) is not Energised until all of itsfinal-circuits have been completed, and Inspected and Tested .

 

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Electrical Safety& Safe isolation procedures for ( low-Voltage-Installation )

Re-cap : Regulation’s BS-7671:2008:2011:

Regulationsgives ( Technical-Guidance ) on the Regulations .

It’s purposeis to amplify the Nature of the precautions in general terms so as to help inthe achievement of high standards of electrical-safety in compliance with theduties imposed . HSE .

Re-cap

Safe isolationprocedures ,

For all workon LV electrical-equipment or circuit(s), it is important to ensure that thecorrect point of isolation is identified, that an appropriate means ofisolation is used, and that the supply cannot inadvertently be reinstated whilethe work is in progress, The conductors must be proved to be dead at the point of work beforethey are touched . Etc

Re-cap : 2392-10.

In TT-systems, the incoming Neutral-conductor cannot reliably be regardedas being at Earth-potential .
For TT-Supplies, a double-pole-switching-device which disconnects the Line& Neutral-conductor(s) must be used as the Means of Isolation .

 

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The Regulations have stated the Facts .

Note : Table-53.4 . p/149 . Circuit-breaker(s)conforming to BS-EN-60898 are suitable for Isolation .
Miniature-circuit-breakers ( MCBs ) manufactured to earlier standards, such as BS-3871, are unlikely to besuitable for Isolation .
Switchgear conforming to BS-EN60947-3 & circuit-breakers & RCDsconforming to BS-EN60947-2 are suitable for isolation if marked with the symbol.

 

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Re-cap
Isolating Device(s)
Single-pole-switches are the most commonly used to control-circuit’s .
2392-10 : As the Regulations reminds us , These switches ( Isolate ONLY the line-conductor ) feeding the load .

 

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Switch : isa mechanical-device that can carry and break a current ( Under-normal-circuit-conditions )

Disconnector : is a mechanical-device that carriesthe design-current for its ( Intended-purpose )

 

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Re-cap :
The Term “ Isolation & Switching“ as used in BS-7671:2008:2011: refers to four-distinct-functions .
Isolation .537.2 , p/150
Emergency-switching . 537.4 , p/152
Functional-switching . 537.5 , p/153, for thereason of ( Control )
Switching off for , -Maintenance. 537.3 , p/151
Mechanical-maintenance p/152 : 537.3.2.4.
A device for switching off for ( Mechanical-maintenance ) shall be so placed and durably-marked so as to bereadily identifiable and convenient for the intended use .

 

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230V single-phase-supply rated up to 100A, are under the control ofOrdinary-persons,
Switchgear / Controlgear
Comply with BS-EN-60439-3 and Regulation 432.1 ,
Or
Be a consumer-unit incorporating components complying with, BS-EN-60439-3
Consumer-unit : 10 way High-Integrity consumer-unit , Main-switch 100A 230v/ 240V – 50Hz . Main-switch BS-EN-60439-3 , are under the control of Ordinary-Persons
p/284. Particular requirements for,LV switchgear & controlgear assemblies intended to be installed in places where,unskilled-persons having access to their use, BS-EN-60439-3 : 1991

 

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Isolation& Switching :

Isolation – To enableelectrical-work to be carried out safety on the isolate-circuit or equipment .
□ Electrically-skilled or Supervised-person .

Switching off for Mechanical-maintenance :

To enablenon-electrical-work to be carried out safety on the switched-circuit orequipment
□ Non-electrical-skilled-persons

Functional-switching :

To enable proper functioningand control of electrical-equipment
□ The user of the installation

Emergency-switching :

To cut off rapidlyelectrical-energy to remove an unexpected hazard
□ Anyone

 

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BS-7671:2011:

Switch-disconnector : p35 .
A switch which , in the open-position, satisfiesthe ( Isolating-requirements ) specified for a disconnertor .

Emergency-switching : p/27 .

An operation intended to remove, as quickly as possible, danger, which may have occurred unexpectedly.
Functional-switching : p/28
An operation intendedto switch “ On “ or “Off “ or vary the supply of electrical-energyto all or part of an installation for ( Normal-operating-purposes )
Isolation/29
A function intended to cutoff for reasons of safety the supply from all, or a discrete section, of theinstallation by separating the installation or section from every source of electrical-energy

 

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Taking from Extracts: Pastto Present.
TheTerm “ Isolation& Switching “ as used in BS-7671: from 2001 / 2011:
p/29 - Isolation: The definition ofisolation in BS-7671: ( A function intended to cut off for reasonsof safety the supply from all, or a discrete section, of the installation byseparating the installation or section from every source of electrical-energy)
BS-7671: have statedthe facts
Isolation:is provided to permit an electrically-competent-person to work safely on all orparts of an electrical-installation .
Onceelectrical-equipment has been securely isolated from the “ Sourceof energy “ has been discharged, askilled or instructed-person should be able to safely access parts that arenormally live, or may become live, without the ( Risk ofDanger ) from electrical-shock,electrical arcing or explosion or from ( Electrical-powered-equipment &Machines )

The corresponding-definition in the “ Electricityat Work Regulations “ adds the specific requirements that the isolation is tobe ( Secure ) EWR – 1989
This means the Isolated-equipment cannotbe ( Re-energised Accidentally or Inadvertently)
The procedure of “ Isolation“ includes

(a) Correct-identificationof the equipment and circuit to be ( Worked-On )
(b) Disconnection,
(c) Securingthe means of disconnection
(d) Postingnotices &
(e) Proving( Dead) In some cases additional-precautions will also be needed.

 

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Being an Electrician, Risks with this kind of Work !! :13: :icon_bs: “ You don’t get a second-chance “ ( Isolation ) Locking-OFF … ( Verify that All Conductors are indeed dead )


Providingthe Isolator is local to the Extract-fan : 2392-10 – Minimal-risk of : Inadvertently orUnintentionally switched back-ON (Locking-OFF )
There no room forsecond chance(s) in this profession . Stay alert and focused. Distractions can be fatal. ( Withany Circuits )

Re-cap : 2392-10 / 2394 : Facts ( Three-pole-Isolator ) which can be locked-OFF. MK

Isolation will arise duringthe lifetime of any Installation (Domestic-premises)

Local-Isolator in thelighting and extract-fan-circuit for a ( 2392-10 - Windowless-bathroom in Dwellings) Etc

Reason – TT-system .Isolate the fan from the ( Source of energy) in Order to work safely on it . boththe Line-conductor & Neutral-conductor(s)will need to be Isolated .

Part of theIsolation-procedure is to ( Verify that All Conductors are indeed dead )

Inadvertently orUnintentionally switched back-ON (Locking-OFF )

I00A Main-Switch in the Consumer-Unit ( Forma perfectly adequate means of Isolation ) Precautions - ( Locking-OFF )

• Circuit-breaker in the Consumer-Unit .Installation forming part of a , TN-system where theNeutral-conductor can be regarded as , being reliably connected with Earth, itmay not be necessary to disconnect both (Conductors ) and safeisolation may be able to be achieved by isolating the ( Line-conductor ) by means such as switching-OFF and locking-OFFthe appropriate-circuit-breaker … Appropriatecircuit-breaker providing the device is suitable for such Use .

P/150 - 537.2.1.1. Everycircuit shall be capable of being (Isolated ) from each of the line-supply-conductors. In a TN-S or TN-C-Ssystem, it is not necessary to isolate or switch the neutral-conductor where itis regarded as being reliably connected to Earth by a suitable-low-impedance .

Provision may be madefor isolation of a group of circuits by any common-means. If theservice-conditions allow this .

► P/150 . 537.2.1.2. Suitable means shall be provided to prevent anyequipment from being ( Inadvertently or Unintentionally Energized ) Etc

( Three-pole-Isolator ) which can be locked-OFF. Your Reason – Securing the means ofIsolation is thereby “ Simplified“

• Part of the Isolation-procedure is to (Verify that All Conductors are indeed dead )

• Inadvertently or Unintentionally switchedback-ON ( Locking-OFF )

Re-cap:Table 53.4 – P/149 Guidance on theselection of protective, isolation and switching devices . BS-7671:2011: have stated the Facts .

… Appropriate circuit-breaker providing the device is suitable for such Use .

Re-cap: P/405 - Isolationand Switching
WindowlessBathrooms:
Windowless bathroomsand toilets have to be fitted with a fan that includes a timer-circuit to ensurethe fan continues to run for a period after the light has been switched OFF

 

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“ Back tosome Basic’s “

BS-7671:2011: Must state the facts .

Re-cap . 17[SUP]th[/SUP] Edition requirements for ( Testing of RCDs)
p/193 - 612.8.1. following requirements in terms of ( Verification of installed RCDs )

612.8.1. requires the effectiveness of automatic-disconnection of supply by ( RCD ) ► To be Verified using , test-equipment meeting the requirements of BS-EN-61557-6 . ( refer ) GN-3 / p/81 . ◄

4.1 – Instrument-standard . ( Thebasic-instrument-safety-requirements )
BS-EN-61557-6 : Electrical-safety in low-voltage distribution-systems up to 1000V a.c .& 1500V d.c.
Equipment for testing , measuring or monitoringof protective measures , Residualcurrent devices – ( RCDs )

BS-7671:2011: Must state the facts ( Protective Measures ) Residual current devices – ( RCDs ) in:
p/193 . TN – Systems , TT – Systems , & IT– Systems .

This is to confirm that the relevantrequirements of . Chapter – 41 ( Protectionagainst electric-shock are Met ) p/49 :icon_bs: