Re-take - Useful Information for 2394 :

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Q) 30mA is required to havethree-tests-applied . what are they . & what currents would need to beapplied .

50% . of 30mA , 15mA . the RCD . should not trip .
100%. of 30mA , 30mA the RCD . would trip inunder . 300mS . NoteBS-EN. ◄
500%. of 30mA , or 150mA . the RCD . should trip inunder 40mS … ( 5 x 30 = 150mA ) 5 x 500% .

RCD- Testers .

GN-3: p.84
i). Should be capable of supplying full-range of test-currents . 50% . 100% . 500%. ½ . x1 . 5 x .
ii). -&-s . Test -current should be applied for . no-longer than . 2 seconds . RCD - Only
iii). Instrument to . BS-EN-61557-6 . will satisfy the above .

Re-cap. GN-3. p.58
Operationof . residual-current-device .
411.4.5.
For each of the tests . readingsshould be taken on . both positive & negative . half-cycles and the . longer-operating-time-recorded. :13:

GN-3: has reminded us . p.58
Prior to these RCD-tests .it is essential . for safety-reasons .that the earth-loop-impedance . is testedto check . the requirements have been met .

 

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My mistake .

50% . of 30mA , 15mA . the RCD . should not trip .
500%.of 30mA , the RCD . should trip in under40mS

What do we require. 2394 : reading- material
Regulations BS-7671:2008:2011:
Guidance - Note 3 .
O.S.G. - 2011 .

Q) . How are live-conductors , in a 3 -phase-circuit indentified ? A ) . Part- 5 . Table - 51 . p.116 . Identification of conductors .
Q ) . State :- the methods for selecting the correct-type , and size of the , Main-protective-bonding-conductor . ? A) .544.1. p.167 .
Q ) . State :- the methods for connecting the , Main-earthing-terminal , to Earth in electrical-installation . ? A) . 542.1.100 . p.158
Q ) . Describe in whichcase the . Electrical-Installation-Certificate is to be used. ? A) . 631.1. P.195

 

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State :
a) . Two-statutory-documentsthat have a direct- influence upon , Inspection & Testing .
b) . The legal-status of , HSE - GN-38 document on ,electrical-test-equipment for electricians .

a). Health &Safety at Work Act 1974 . Electricity at Work Regulations -1989
b). This is a , Guidance-note. & therefore cannot be . (Statutory ) Non-Statutory . ( Written-exams)

State :
The legal-status of each of the following .
a) . BS-7671:2008:2011: . A) Non-Statutory.
B) . The On-Site-Guide . A) Non-Statutory.
c) . The Electricity at Work Regulations 1989 . . Statutory

State :
a) . When an Initial-inspection & Test should becarried-out .
b) . The precautions to be taken during an ., Inspection & Test .
a) . During and on completion,before being put into service . p.189 - 610.1
b) . Avoid danger to persons, livestock and damage to property. p.189 - 610.1

Initial-Verification . p.189 - 610.1
Every-installation shall, during erection and on completion , before being put into service . be Inspected & Tested to verify . ETC.

1 down : Precautions shall be taken to , avoid danger to persons and property . and installed-equipment. during Inspected & Testing .

 

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Q ) . What is the difference between ,Basic-protection , & Fault-protection ?
- Basic-protection against . electric-shock under-fault-free-conditions. p.23 . under-normal-condition .
- Fault-protection against . electric-shockunder-single-fault-conditions . p.28 . under-fault-conditions .

Chapter - 41 . to understand these ,fundamental-principles . 411.2 . 411.3 . p.52 / 53

Q ) . Describe the methods of , Basic-protection & Fault-protection , regarding. automatic-disconnection of the supply. ( ADS ) A). 411.
Q ) . State : the difference between , Overcurrent & Fault-current . 433 . 434 .p.81 / p.83 .

Overcurrent : An overcurrent-exceeding the rated-valve , forconductors the rated-value is the current-carrying-capacity . p.32
Fault-current : A current-resulting from a fault . p.28

 

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Q ) . What : does the specification of “ BS-EN-60898 “ standsfor . A) . Appendix - 1 . p.277
Q ) . State : the maximum-disconnection-time , for an A.C. low-voltage ., final-circuit not exceeding 32A . A) . Table - 41.1. / 0.4s .
Q ) . State : the need for , initial-verification . A) . 610 . p.189
Q ) . State : the minimum-values of , insulation-résistance . A ) Table- 61 . p191
Q ) . State : requirementsfor , periodic-inspection & testing. . A) 634.1. p.196
Q ) . Describe : inwhich case the , Electrical-installation-certificate , is to be used. A) 631.1 . p.195
Q ) . After : completing an , Electrical-installation-certificate , to whomit will need , to be given a copy . A). Appendix - 6 .

Q) . 551.4.4. Portable-Generating-Sets , can be used tosupply . ?? refer . O.S.G. p 19
- Permanent-installations .
- Temporary-installations .
- Portable-equipment .

Not in the O.S.G.
When supplying ,permanent or temporary-installations .generating-sets . can be :

- The only means ofsupply .
- Means of supplywhen , the public-supply is not available - ( Standby-supply )
- Supply inparallel with the public-supply .

 

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Inspection & Testing . Re-cap

C1 : Danger-present. Risk of injury.Immediate-remedial-action-required .
C2 : Potentially-dangerous -urgent-remedial-action-required.
C3 : Improvement-recommended .

The recording of either a . C1 or C2 - observation in the. ( EICR ) would result in an . unsatisfactory-outcome .
In other words , the installation would not bedeemed-compliant to . BS-7671:2008: (2011) in this case the recipient of the report ,must take action , either immediately or urgently, in accordance with the .observation made .

By highlighting-exceptions to a ,satisfactory-installation , the ( EICR ) rapidly draws-attention to the issues and theappropriate-response to them . if an issue is recorded it should be dealt with. ( Note : the EICR .is covered by . regulation - 631.2. 631.4. 631.5 . 634.1 . )

Certification & Reporting :
631.2 . p.195 .
Upon-completion of the . periodic-inspection & testingof an existing-installation , an Electrical-Installation-Condition-Report ,based on the model given in Appendix - 6 .
shall be provided.Such-documentation shall include-details of the extent of the installation .& limitations of the . inspection & testing . covered by the Report . together withrecords of inspection , the results of testing and a . recommendation for theinterval-unit the . next-periodic-inspection .

Certification & Reporting :
631.4 . p196
Electrical-Installation-Certificates ,Electrical-Installation-Condition-Reports . &Minor-Electrical-Installation-Work-Certificates . shall be compiled and signedor otherwise-authenticated by a . competent-person or persons .

Certification & Reporting :
631.5 . p196
Electrical-Installation-Certificates ,Electrical-Installation-Condition-Reports . &Minor-Electrical-Installation-Work-Certificates . may be produced in anydurable medium , including written , & electronic-media . Regardless of themedia used for . original-certificates . reports or their-copies ,their-authenticity and integrity shallbe verified by a reliable-process or method . The process or method shall also, verify that any copy is a true-copy of the . original .

Periodic-Inspection & Testing :
634.1 . p196
Following the periodic-inspection & testing describedin . Chapter - 62 , an Electrical-Installation-Condition-Report , together with schedules of inspection , & schedules of test-results ,shall be given by the person carrying out the inspection , or aperson-authorized to act on their-behalf , to the person-ordering theinspection. These-schedules shall be based on the models . given in Appendix -6 . The schedules of test-results , shall record the results , of theappropriate-tests required of . Chapter - 61 .

 

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Overlooked . Q) . State : examples of installations within the scope of BS-7671:2008:2011: A) . 110.1. Regulations apply to the design, erection and verification, of electrical-installations , such as thoseof : Etc i) . residual-premises. ii) . commercial-premises . iii) . public-premises . v) . industrial-premises. incorporating - Amendment - No . 1 xv) . medical-locations xvi) . operating and maintenance-gangways . Q) . State : the relationship of , BS-7671:2008:2011: to statutory-regulations . A) . 114. 115 . 113 - Equipment : p.15 The Regulations - apply to items of , electrical-equipment only so far as, selection & application of the equipment in the installation are concerned . The Regulations - do not deal with requirements for the construction of assemblies of , electrical-equipment, which are required to comply with appropriate-standards .

- - - Updated - - -

Overlooked .

Q) . State : examples of installations within the scope ofBS-7671:2008:2011: A) . 110.1.

Regulations apply to the design, erection and verification, of electrical-installations , such as thoseof : Etc
i) . residual-premises .
ii) . commercial-premises .
iii) . public-premises.
v) . industrial-premises.

incorporating - Amendment - No . 1
xv) . medical-locations
xvi) . operating and maintenance-gangways .

Q) . State : the relationship of , BS-7671:2008:2011: to statutory-regulations . A) . 114. 115 .

113 - Equipment: p.15
The Regulations - apply to items of , electrical-equipment only so far as ,selection & application of the equipment in the installation are concerned .
The Regulations - do not deal with requirements for the construction of assemblies of , electrical-equipment, which are required to comply with appropriate-standards .

 

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Q) . Define : the meaning of , Earth-fault-loop-impedance.
p.26 . Earth-fault-loop-impedance , The impedance of theearth-fault-current-loop , and ending at the point of earth-fault , Thisimpedance is denoted by the symbol ( Zs )

( PEFC ) shown by calculation .
Is measured between, Line-conductor & Earth , at theorigin . 230V / 0.1Ω = 2300A . or 2.3kA . as it should be recorded on Certificate . Uo / Ze
.
( PFC ) prospective-fault-current .
612.11. ( PEFC ) shall be measured . at the Origin . Domestic-installations .

GN-3 : p.83 . Earth-fault-loop-impedance-testers .
To minimise , electric-shock-hazard , from the potentialof the , protective-conductor , the test-duration should be within safe-limits . This meansthat the instrument should cut , off thetest-current after , 40mS

Known your test-instrument : GN-3 . BS-EN-61557-3. Part - 3 . Earth-fault-loop-impedance-tester.

Circuit-loop-impedance :
612.9. Whereprotective-measures , are used which require a knowledge of , earth-fault-loop-impedance , the relevant-impedance .shall be measured . Etc

 

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Safely-isolate-electricity :
Safely-isolate-electrical-circuit(s) : Securing the device in the “ OFF “ position .
Isolate-devices-safely :

State : Q ) . state the reasons for carrying out . Safe-Isolation.
Q) . State : the requirements of the , Electricity atWork-Regulations 1989 , for safe-inspection ofelectrical-systems & equipment .
Safe-Isolation . Low-voltage-installation(s)

Statutory-requirements . The most important- Statutory-requirement, concerning work carried out , On or Near electrical-installation(s) is the . Electricity at Work-Regulations - 1989 . These Regulation(s) within ( EaWR ) Particular - relevance to ( Safe-isolation ) are number(s) are 12) . Means of cutting off the supply , and forisolation .13) . ( Precautions for work on , equipment made Dead ) Regulation - 12(1) (b) States : that where necessary to ( prevent-danger ) suitable means shall be available for the , isolation of any electrical-equipment , where isolation means the disconnection and separation of the electrical-equipment from ( Every source in sucha way that the disconnection and separation is secure ) (2)) refers , The Memorandumof Guidance on the , Electricity at WorkRegulation(s) - 1989 . HS(R) 25) Heathand Safety Executive , advises withreference to Regulation - 12 (1) above that isolation is the process ofensuring that , that the supply to all , or a particular-part of an installation-remains -switched OFF , and that inadvertent-reconnection is prevented . Preventing-inadvertent-reconnection is covered in Regulation- ( 13 ) Electricity at Work Regulation(s) - 1989 . ( Which requires that )
Adequate-precautions , shall be taken to prevent electrical-equipment , which has been made ( Dead ) in order to prevent-danger , while-work isbeing-carried-out On or Near that equipment , from becoming-electrically -charged during that work , if dangermay-thereby-arise .

Regulation - ( 13 ) in HR(R) 25 . highlights the ( Need to lock-OFF ) Switching-device , being-used to provide-isolation , or whereisolation has been , achieved by a ( Fuse ) by their-removal and retention in a safe-place-during the isolated-period .
132.15. Isolation and Switching . relevance in terms of , safe-isolation . Regulation - 132.15.1. refer . Regulation - group . 537.3. switching OFF for mechanical-maintenance . Table - 53.2. summarises the suitability ofparticular-protective , Isolation & Switching-devices .

 

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This could be my - computer , or scrambled on the download . Sorry about-that

Safely-isolate-electricity :
Safely-isolate-electrical-circuit(s) : Securing the device in the “ OFF “ position .
Isolate-devices-safely :

State : Q ) . state the reasons for carrying out . Safe-Isolation.
Q) . State : therequirements of the , Electricity at Work-Regulations 1989 ,for safe-inspection of electrical-systems & equipment .

Safe-Isolation . Low-voltage-installation(s)

Statutory-requirements .
The most important- Statutory-requirement ,concerning work carried out , On or Near electrical-installation(s) is the . Electricity at Work-Regulations - 1989 . These
Regulation(s) within ( EaWR )

Particular - relevance to ( Safe-isolation) are number(s) are
12) . Means ofcutting off the supply , and for isolation .
13) . ( Precautions forwork on , equipment made Dead )

Regulation - 12(1) (b) States : that where necessary to ( prevent-danger ) suitable means shall be available for the , isolation of any electrical-equipment , where isolation means the disconnection and separation of the electrical-equipment from ( Every source in sucha way that the disconnection and separation is secure )
(2)) refers , The Memorandum of Guidance on the , Electricity at Work Regulation(s)- 1989 . HS(R) 25) Heath and Safety Executive , advises with reference toRegulation - 12 (1) above that isolation is the process ofensuring that , that the supply to all , or a particular-part of an installation-remains -switched OFF , and that inadvertent-reconnection is prevented .

Preventing-inadvertent-reconnection is covered in Regulation- ( 13 ) Electricity at Work Regulation(s) - 1989 . ( Which requires that )
Adequate-precautions , shall be taken to prevent electrical-equipment , which has been made ( Dead ) in order to prevent-danger , while-work isbeing-carried-out On or Near that equipment , from becoming-electrically -charged during that work , if dangermay-thereby-arise .

Regulation - ( 13 ) in HR(R) 25 . highlights the ( Need to lock-OFF ) Switching-device , being-used to provide-isolation , or whereisolation has been , achieved by a ( Fuse ) by their-removal and retention in a safe-place-during the isolated-period .


132.15. Isolationand Switching . relevance in terms of ,safe-isolation .
Regulation -132.15.1. refer .

Regulation - group . 537.3. switching OFF for mechanical-maintenance .
Table - 53.2. summarises the suitability of particular-protective , Isolation & Switching-devices .

 

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PVC - cables , Old to New . Why does this come up in Exams ?? 16[SUP]th[/SUP] Edition . The components of a wiring-system , including-cables and wiring-enclosures , shall beinstalled or handled-only at temperatures within the limits stated in the relevant-product-specification or asrecommended by the manufacturer . Regulations : PVC - cables , At lowtemperature PVC - cables insulation canbecome brittle when handled . 522.1.2. 2008 & 2011 . p.123. Wiring-system-components , including cables & wiring-accessories , shall only be installed or handled at temperatures within the limits stated in the relevant-product-specification or as given by the manufacturer . PVC - cables : must not beinstalled when theambient-temperature is ( 0°C ) refer IET - Regulation . 522.1.2.

- - - Updated - - -

PVC - cables , Old to New . Why does this come up in Exams ??

16[SUP]th[/SUP] Edition . The components of a wiring-system , including-cables and wiring-enclosures , shall beinstalled or handled-only at temperatures within the limits stated in the relevant-product-specification or asrecommended by the manufacturer .


Regulations :
PVC - cables , At low temperature PVC - cables insulation can become brittlewhen handled .

522.1.2. 2008 & 2011 . p.123.
Wiring-system-components , including cables & wiring-accessories, shall only be installed or handled at temperatures within the limits stated in the relevant-product-specification or as given by the manufacturer .

PVC - cables : must not be installed when the ambient-temperature is ( 0°C ) refer IET - Regulation . 522.1.2.

 

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Doing some calculations for conduit . re-cap
Cable capacities of Conduit. Appendix E . p.133 - O.S.G.

Six 2.5mm[SUP]2 [/SUP] , PVC -insulated-cables , are to be run in a conduit containing two bends between boxes , 10mm apart. determine the minimum-size of conduit to containthese cables .

The factor for , one 2.5mm[SUP]2 [/SUP] cable = 30
The sum of the cable-factor = 6 x 30 = 180.

Next : Table - E 4 . p.136 . 10m → 2 x bends - 25mm = 260 .
Table - E 4. 20mm conduit containing 2 x bends .only has a factor of 141 . Whichis less than . 180 .
Therefore : 25mm[SUP] [/SUP] conduit is theminimum-size to contain these-cables .

Ten 1.0mm[SUP]2 [/SUP] , PVC - insulated-cables are to be drawn into conduit , which is 6m long between-boxes and contain one-bend . 4.0mm[SUP]2 [/SUP] PVC -insulated-CPC . is also included .

Determine the minimum-size of conduit to contain these-conductors . Table - E3 . long straight runs Over 3m ,
Cf) One 1.0mm[SUP]2 [/SUP] cable = 16
Cf) One 4.0mm[SUP]2 [/SUP] cable = 43
( 10 x 16 ) + ( 1 x 43 ) = 203 . 160 + 43 = 203

Table - E 4 . 20mm conduit , 6m 1 x bend has a factor of 233.
16mm conduit . containing 1 x bend has a factor of 143. which is less than 203 ,
The sum of thecable-factors and , therefore .20mm conduit is the , minimum-size to contain these cables .

Table - E 4 . O.S.G. reminds us . only gives factors for conduits up to 32mm, in diameter, which would indicate that conduits larger than thisare not in , frequent or common-use .

O.S.G. bottom-page: Additional-factors:
38mm , diameter use 1.4 x ( 32mm factor )
50mm , diameter use 2.6 x ( 32mm factor )
63mm , diameter use 4.2 x ( 32mm factor )

When acable-enclosure-greater than , 32mm is required because of the number or size of the conductors , it is generally more economical and convenient to use trunking .

Where the wring-system passes through-elements , ofbuilding-construction such as floors . walls . any damage must be made-good
p.132 . Fire-safety: Regulation - 527.2. 527.2.2. Wiring-system such as aconduit-system . Etc

 

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Re-minder : Human-errors , being careless and notpaying-attention to what you should be doing at work .
A Hazard : is something with the Potential , to cause harm .
Risk : is thelikehood of harm actually being-done . Why do we do aRisk-Assessment .

2394 : reading- material
Regulations . is reminding us.
GN-3 . is reminding us .
O.S.G. is reminding us .

p.89 . O.S.G. - Guidance on Initial-Testing of Installation(s) .

10.1. p.89 . Safety and Equipment .
HSR25 , EWR , Regulation - 14 .

Electrical testing involves-danger.
The Electricity atWork Regulations -1989 . States : that working on Live-conductors is permissible ( Provided ) that it is reasonable in all thecircumstances for the work to be carriedout and that , suitable-precautions aretaken to prevent-injury .

While live-testing may be required in order to find the ( Fault) Live-repair-work must ( Not ) be carried-out , The individual-circuit or item of equipment , must first be isolated .

Regulations . p.29. Isolation . A function intended to cut ( OFF ) for reasons of safety the supply from all .
GN-3 reminds us . Thecircuit must be Isolated using a “ Safe-Isolation-procedure “

Live-testing of electrical-installationsis , therefore , reasonable as it is a , recognised-method of assessing the suitability and safety of an electrical-installation: suitable-precautions must be taken by, employing the correct-test-equipment , andsuitable-personal-protective-equipment .

O.S.G. reinforces this : Although Live-testing and diagnosis for fault-finding may bejustifiable , there could be ( No - Justification ) for any subsequent-repair-work to becarried-out-live .

610.1. : O.S.G.
It is the Test-operative’s-duty toensure their own-safety . and thesafety of Others. whilst working through Test-procedures. 612.1.

612.1. Re-minder .
i) . knowledge and experience of thecorrect-application and use of theTest-Instrumentation , leads , probes and accessories ( isof the greatest-importance )
ii) . checking thatthe Test-instrumentation is made in accordance with the appropriate-safety-standards such as , BS-EN-61243-3 . for two-pole-voltage-detectors and BS-EN-61010 or BS-EN-61557(?) for instruments .
iii) . checking before each use that all leads , probes . accessories( Including all devices such as crocodile-clips used to attach to conductors ) Etc.

GN-38: iv) observing the safety-measures andprocedures set out in , HSE - Guidance - Note GS-38 , for all instruments. leads , probes and accessories . Sometest-instruments-manufactures advise thattheir instruments be used in conjunction with ( Fused-test-leads and probes )
Others-advise theuse of non-fused-leadsand probes when the , instrument has in-built-electrical-protection , butit should be noted that such , electrical-protection does ( Not ) extend tothe ( Probes& Leads )

So : TheTest-instruments and Test-leadsused by the electrician for testing anelectrical-installation , must meet all requirements of the relevant-regulations .

Test-Instrument-Leads .

British-standards :
Heath & SafetyExecutive .guidance relating to , Test-Instrument-Leads .
When using , electrical-test-equipment , & to meet therequirements of the , Electricity atWork Regulations - 1989 .

The Electricity atWork Regulations - 1989 . require those in control of ( All ) or ( Part) of an electrical-system , to ensure it is safe to use & maintained .

Heath & Safety Executive . guidance relating to ,Test-Instrument-Leads .

It is important that , ( Fused-test-instrument-leads) are used where there is apotential-risk of a fault-currentpassing through the , test- Instrument-Leads that could cause-damage to the instrument .

 

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612.2.2. Continuity of ring-final-circuit-conductors .

Test :
O.S.G. p.92 . A Three-step is required to verify the continuity of the ,Line , Neutral , protective-conductors & correct-wiring of every , ring-final-circuit . Etc .
GN- 3 . p. 35 . A Three-step is required to verify the continuity ofthe , Line , Neutral , protective-conductors & correct-wiring of every , ring-final-circuit . Etc .

Step 1 : Ohmmeterconnected to ( L[SUP]1[/SUP] & L[SUP]2[/SUP] ) This gives a value for ( Little r[SUP]1[/SUP] )
Step 1 : Ohmmeterconnected to ( N[SUP]1[/SUP] & N[SUP]2[/SUP] ) This gives a value for ( Little r[SUP]n[/SUP] )
Step 1 : Ohmmeterconnected to ( CPC[SUP]1[/SUP] & CPC[SUP]2[/SUP] ) This gives a value for ( Little r[SUP]2[/SUP] )

Step 2 : Line & Neutral , ateach-socket-outlet
Step 3 : Line & Earth , ateach-socket-outlet . Circuit-protective-conductor . ( R[SUP]1[/SUP] +R[SUP]2[/SUP] )

As a check ( R[SUP]1[/SUP] +R[SUP]2[/SUP] ) value should equal ( r[SUP]1[/SUP] + r[SUP]2[/SUP] ) / 4

Refer to GN-3 .

 

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2392-10as its been extended . old notes to help you 2009 / 10
2392-10Course unit 101 ( 2.1 )

1: Which oneof the following Senses is Not used during the Initial Inspection and Testingprocess ?
(a ) Sight ( b ) Touch ( c ) Taste ( d ) Smell

2: Duringthe initial inspection and testing sight would indicate a fault such as ?
(a ) Overheating ( b ) Equipment Overheating ( c ) Vibration of transformer cover ( d ) DamageEquipment

3: Humansenses are used mainly during the ?
(a ) Inspectionprocess ( b ) Testing process ( c ) Certification process ( d ) Safe isolation procedures

4: Touchwould indicate a fault due to ?
(a ) Incorrect cable size ( b ) Arcing due to loose connections ( c ) Incorrect labelling ( d ) Poor fixings of accessories

5: HumanSenses ?
(a ) Are anintegral part of the inspection process ( b ) Should not be used to detect faults’
(c ) Are useful for live circuits only ( d ) Should be used one at a time

unit101 ( 2.2 )
1: An Initial Inspection should be carriedout ?
(a ) After the erection process ( b ) During the Erection process and before Energising
(c ) Before the erection process ( d ) Approved by the Heath and SafetyExecutive

2: All equipment and materials’ should be ?
(a ) To therelevant British Standard or Equivalent
(b ) To a standard agreed by the personordering the work
(c ) To standards set out by the local authority building control
(d ) Approved by the Heath and Safety Executive

3: Which of the following is not an itemfor Inspection ?
(a ) Connection of conductors ( b ) Routing of cables ( c ) Selection and erection to maximise fire
(d ) Isolation and switching devices

4: Labelling of Protective devices , switches andterminals’ ?
(a ) Is not important ( b ) Is essential ( c ) Should all be the same colour labels ( d ) Is only required for MCBs

5: Detailed requirements for selection and erection is given in BS-7671 : 2008
(a ) Chapter 32 ( b ) Chapter 52 ( c ) 41 ( d) 11