Re-take - Useful Information for 2394 :

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No- Socket Covers are in sight .


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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 )

 

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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: