Re-take - Useful Information for 2394 :

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Re-cap :

For installation(s) with a 230V –single-phase-supply , rated up to 100A ,that are under the control of Ordinary-persons . ( Switchgear & Controlgear )
Comply with , BS-EN-60439-3 & Regulation - 432.1. P/80 .

Be a , Consumer-unit incorporating-components-complying with , BS-EN-60439-3 .

Switch-disconnections, BS- EN-60947-3.

432.1 . Protection against overload-current ( Only) Etc
For a , Circuit-breaker making, anyovercurrent up to & including the ( Maximum-Prospective-Fault-Current ) at the point where the device is Installed.

P/284 : BS-EN-60439-3:1991 . defined as .
Particular-requirementsfor , ( LV ) Switchgear &Controlgear assemblies intended to beinstalled in places where ( Unskilled-persons ) have access totheir use , Distribution-boards .

BS-EN-60439-3:1991+A2:2001

Low-voltage switchgear and controlgear assemblies. Particular requirementsfor low-voltage switchgear and controlgear assemblies intended to be installedin places where unskilled persons have access to their use. Distribution boards

P/150 . 537.1.4. General-requirements.
A main-switch intended for operation by ordinary-persons , of a household orsimilar-installation , should interrupt, both live-conductors of a ,Single-phase-supply .

537.1.4. A main-linked-switch or linked-circuit-breaker shall be provided as near as practicable tothe origin of every-installation as ameans of switching the supply on load & a means of Isolationswitch

P/29 . Isolation :- is the function that Allows operatives to work-safety onelectrical-equipment. BS-7671:2008:2011: as defined as :

A “ function-intended to cut off for reasons of safety the supply from all ,or a discrete-section , of the installation by separating the installation orsection from , every-source of electrical-energy

RCCBs , are devicesdesigned to protect against , fault-currents flowing to earth,

 

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Testing . 2392-10 .
Test-method 1 : use the Line-conductor as a return-lead , Otherwise known as the ( R[SUP]1[/SUP]+ R[SUP]2[/SUP] ) method .
Résistance of the ( CPC )
Q . Why do I need to bother with the, Résistanceof the Line-conductor ?
Reason being : can use Line-conductor as part of the circuit . ( Willyou use a Wander-lead , NO )
Reason : Your ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) reading can be used for working out your ,Earth-fault-loop-impedance-value . (Circuit-loop-impedance )
Have you , Obtained Polarity . at the same-time . ( L / CPC )
Most used methodused for ring-final-circuit(s) Line-conductor runs alongside a ( CPC ) conductor , factor is utilised in this Test . :yes:

 

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2392-10 . better-understanding.

Test-method 2 : uses the , Wander-lead , it’s title ( R[SUP]2[/SUP] - method)

Your Reason . Wander-lead is a simply a long-length of conductor that can be moved to different-points . in anInstallation .

( R[SUP]2[/SUP] - method) confirm the continuity of , Equipotential-bonding-conductor(s) 612.2.1. :svengo:

2392-10, you do not have a, Line-conductor as a return-path. “ Simple “

 

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For , safety-reasons ... (You may have Implication(s)

( R[SUP]2[/SUP] - method)
Ensure that you have the permission beforehand ( Disconnectany parallel-paths) main-protective-bonding-conductor . Etc

 

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Design-Procedures : of Any- BS-7671: 2392-10 : As , Installers / Designers.

Safety of , Life & Property, are the first-two-important-factors to be considered in the ( Design ) of low-voltage-systems.( LV )

 

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2392-10:- How significant is Insulation-résistance-testing !!

Insulation starts to age as soon as it's made. And, agingdeteriorates its performance.

Installation-résistance-test : Integrityof Conductor(s).

Insulation-résistance, confirmthe reliability of the circuit , in question .

( shorted-connectionwould be obvious from the test-results)

Initial-verification: 2008:2011:
Every-installationshall , during-erection & on-completionbefore being put into service , be . ( Inspected & Tested to verify )

Regulation - 612.3 ( Under-the-section for Initial-verification) :icon_bs:

GN-3 : States :
Insulation-résistance-testedduring various-stages of installation to ( Prove ) the integrity of installed-cables .

 

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2392-10 , thereis always a reason, when I post anyarticle(s) for your benefit . ( can you HIT the Thank-you-button)

 

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( 1MΩ / 2MΩ ) Extracts.

2008: GN-3 , States :

Whole-installation, Periodic-testing... ( Existing )
Single-circuit(s), Initial-Verification... ( New-installation )

Insulation-résistance to Earth.
Single-phase .
Test between the line &neutral-conductor(s) connected together& Earth at the appropriate , distribution-board, of for circuits /equipment not vulnerable to ,insulation-résistance-testing , line & neutral-separately to Earth .
For circuits containing two-way-switching ortwo-way & intermediate-switching ,the switches must be operated one at a time & the circuits subjected to additional-insulation-résistance-test(s)

Where a low-reading is obtained ( Less than 2MΩ ) it may be necessary to test each-conductor-separately to earth , after ensuring that all equipmentis disconnected .

Résistance-readings obtained should be not less than the ,minimum-values , refer , Table – 61

• If a sufficient-high-reading cannot be obtained on the , ( Whole-installation) GN-3 - requires us to . Test ( On any individual circuit(s) discover where any fault is occurring .

Sixth-edition : Inspection& Testing (GN3) provides us with an opportunity comment onthe critical-importance of the Verification-process.
GN3 is, primarily concerned with Part 6 of BS-7671 – Inspection and Testing.
2392-10 , You are only testing , Single-circuits (T&E ) on Initial-Verification. ( You will not Test , Whole-installation)

 

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fifth-edition- 2008 – GN-3 : P/38 , Extracts .
Although an , insulation-résistance-value of not less than ( 1.0MΩ ) complies with the Regulations , where aninsulation-résistance of less than ( 2MΩ ) is recorded the possibility of alatent-defect-exists , in these-circumstances ,
Each-circuit should be tested-separately .
GN-3 , re-cap .
This will help identify (i) whether one-particular-circuit in theinstallation has a lower-insulation-résistance-value , possibly-indicating alatent-defect that should be ( Rectified) Or
(ii) whether the low-insulation-résistance-represents, for example , the summation of individual-circuit-insulation-résistance &as such may not be a cause for concern .

 

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From , 1991 / 2011 . BS-7671 : :icon_bs:

P/29 . Insulation : Suitable non-conductive-material enclosing, surrounding or supporting a conductor .

 

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Useful-junk .
P/29 , Leakage-current : Electric-current in anunwanted-conductive-path , under normal-operating-conditions .
Touchcurrent :- also known, as earth-leakage-current must be withinspecified limits for its Class. :aureola:
Class I equipment, the earth-leakage-current is thecurrent that flows in the earth supply conductor during normal operation of theequipment.
Class II equipment, leakage is measured to earth fromaccessible conductive-parts of the enclosure

 

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2008: GN-3 ,States : if test an installation as a whole
Insulation-résistance to earth.
" Although aninsulation-résistance-value of not lessthan 1.0 MΩ complies with the Regulations, where an insulation resistance ofless than 2MΩ is recorded the possibility of a latent defect exists. ( In these circumstances, each circuit should be tested separately ) "

2392-10
" Although an insulation-résistance-value of not less than (1MΩ complies with the Regulations ), New-installations should not yield test results this low "

( 299MΩ ) . reason(s) , New-installation .

 

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Circuits must be designed that are fit for purpose andsuitable for the load they are intended to supply. They should be correctlydesigned in accordance with BS-7671.

Useful-junk .

New numberingsystem introduced for UK-only national regulations . :icon_bs:

In Amendment - 1 , UK national regulations willend in 100, 101,102, etc.

Regulation , 522.6.7 now 522.6.102

Regulation , 433.1.5 now 433.1.103

This will show-regulations that are specificto the ( UK only and not used in theEU )

 

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Useful-junk

1988 an agreement was reached that , voltage-levels across Europe should be unified at 230V , Single-phase & 400V , Three-phase with effectfrom , January 1[SUP]st[/SUP] 1995 .

Tables in the 17[SUP]th[/SUP] Editionhave been , recalculated to take account of the unified-voltage-levels . 230V & 400V

BS-7671: Made a Stand . :icon_bs:

Introduction of the ( Free-European-Marker in 1993 ) caused serious-problems for , UK electrical-contractors . IEE / IET wiring-regulations were held in high-esteem .they had , no-legal-status thatwould require Europeans who werecarrying out , installation-work in the UK to abide by them .

1992 , when the , IEE / IET wiring-regulation(s) became a (British-Standard ) BS-7671: giving them therequired-international-standing , from 2010 , BS-7671:

 

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Useful-junk: 2011:
Definition :- JPEL/64 . Regulation – GP / 10 . as at June 2011.
The , UK National-Committee-responsible for , BS-7671: is ( JPEL/64 ) :icon_bs:
J ... joint IET / BSI – committee .
P ... Power .
EL ... Electrical .
64 ... IEC– designation for Committees dealingwith , low-voltage-electrical-installations .

 

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BS-7671:2011: have stated the facts for us . :icon_bs:

2394 : RCCBs are still out-there ,
BS-EN-61009-1 ( RCBO ) BS-EN-61008-1 – ( RCCBs )

p/286 . BS-EN-61008-1:2004 + 12:2009
Residual-current-operated-circuit-breaker(s) without, integral-overcurrent-protection for household & similar uses ( RCCBs ) – Part 1 : General-rules
Introduction , Chapter -41 , 411.4.9.
411.4.9. . P/57
Where an , RCD is usedto satisfy the requirements ofRegulation , 411.3.2.2. the maximum-values of , earth-fault-loop-impedance in ,table- 41.5 may be applied for non-delayed RCDs to BS-EN-61008-1. & BS-EN-61009-1 . for anominal-voltage , ( Uo of 230V ) in such-cases , anovercurrent-protective-device shallprovide protection against , overload-current & fault-current in accordancewith Chapter – 43 .

411.3.2.2. Automatic-disconnection in case of a fault .
The maximum-disconnection-time stated in , Table -41.1 shall be applied to final-circuitsnot exceeding 32A .
Table 41.5.
Maximum , earth-fault-loop-impedance( Zs ) for non-delayed RCDs . to BS-EN-61008-1. & BS-EN-61009-1 for ( Uo of 230V ) Regulation – 411.5.3.

Table 53.4. Guidance on the selection of protective , isolation & switching-devices .

710.411.3.2.1. Medical-Locations .
Care shall be taken to ensure that ,simultaneous-use of many-items ofequipment-connected to the same-circuit , cannot-cause unwanted-tripping of the residual-current-protective-device ( RCD )

710.410.3.4. Exhibitions , Shows & Stands .
A cable-intended tosupply-temporary-structures shall beprotected at its origin by an RCD whose-rated-residual-operating-current , dosenot exceed 300mA , This device shallprovide a delay by using a device in accordancewith BS-EN-60947-2 , or be the ( S – type in accordance with BS-EN-61008-1 ) or BS-EN-61009-1for discrimination with RCDs protecting-final-circuits .

Note : The requirement for ,additional-protection relates to theincreased-risk of damage to cables in temporary-locations.

721.411.1 Electrical-Installations in Caravans & Motor-caravans .
Where-protection byautomatic-disconnection of supply is used ( Section – 411 ) an RCD – complying with , BS-EN-61008-1 . & BS-EN-61009-1, interrupting all-live-conductors’ shall be provided having the characteristics specified in Regulation –415.1.1. & the wiring-system shall include a circuit-protective-conductor which shall be connected to . Etc . refer . 721.411.1 (i) (ii) (iii)

740.410.3. Section – 740 .
Automatic-disconnectionof supply to the temporary-electrical-installation shall be provided at theorigin of the installation by one or more RCDs with a rated-residual-operating-current not exceeding 300mA , the RCD shall incorporate, time-delay in accordance with BS-EN-60947-2 , or be the ( S – type inaccordance with BS-EN-61008-1 ) or BS-EN-61009-1 , where necessary to provide discrimination with RCDs protecting-final-circuits .

740.411 , Note .
p/295 . Appx 3, Table – 3A . Time / current , characteristics of overcurrent-protective-devices & RCDs

am justbring it to your Attention . BS-EN-61008-1

 

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What’s in a Book.

Re-cap : GN-3 ,P/11 , offers Us Guidance. 2394 . What will help me in my ,Exams . ( Better-understanding )

Safety:
Electrical-testing inherently-involves some degree of Hazard .

It is the Inspector’s-duty to ensure his ( or her ) ownsafety , & that of others , in the performance of the test-procedures .

The safety-procedures detailed in , Health &Safety-Executive-Guidance , Note GS-38 .( revised )

Electrical-test-equipment for use by , electrician’s should be observed . When testing does not require the equipment orpart of an installation to be ( Live )

It should be made ( Dead) & ( Safety-isolated)

Guidance on ( Live & Dead-working ) Safety-Executive-publication , Memorandum of guidanceon the , Electricity-at-work-Regulations – 1989 ( HSR.25 )

Guidance on, Safe-isolation-procedures can be found in a ,best-practice-guide-published by the , ESC .

 

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What are the Objectives of the IET– Wiring-regulation(s) BS-7671:2008: 2011.

To ensure the ( Protection) of people & livestock from , fire , shock or burns from any installation thatcomplies with their-requirement’s.

 

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What in the Eyes of , The IET-Wiring-Regulations ( Cover) Main-cover , The Words , Wiring-Regulations.

Re-cap , TheRegulations cover both : ( What ?? ) :icon_bs:

Electrical-installation(s).
Electrical-equipment .

 

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It assumes that behind every Electrician thereis a Designer. :icon_bs:

Ohm’s-law , the current-flowing will depend on thevoltage-applied & the résistance of the current-path.

In the Eyes of ,BS-7671:2008:2011:
Limit the severity of , Electric-shock is the limitation of ,Earth-fault-loop-impedance .

As Electrician’s, we know this all too well . Electric-shock results from contact with a conductor that form-part of a circuit . ( Live )

Circuit-breaker(s) :- Overcurrent-protective-system will offer , no-protection
RCDs . RCBOs /MCB . RCD with an opening-current of 30mA . ( BS-7671: do not claim great expectations , Additional-protection ) May-do-so . 2392-10 . Can a RCD become faulty or is faulty . that’s why Testing is very-important .

GN-5 : The effects of an , Electric-shock ... ( Dependent on the current )
Depends on two-factor(s)

• Value of shock-current-flowing .
• Time for whichit flows . ... ( Additional-protection )

Human-body is composed largely of water, & has very-low-résistance ( Theskin has very-high-résistance )