Re-take - Useful Information for 2394 :

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Q) . Where a clamp is used for bonding-purposes . a permanent label shall befixed in a visible position with the wording ?
A) . “ Safety-Electrical-Connection “ Do Not Remove . 514.13.1 .p.118 . ( EICR -. C2 . C3 . ??? )

 

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Underpinningknowledge 2392-10
Thecandidate will be able to :

Identifythe general requirements for inspection and testing of installations .

Statethe need for diagrams . chats or tables to be available prior to theverification process .

Indentifythe items to be checked during the inspection process .

Statethe tests which may need to be carried out on initial verification .

Comparetest results with relevant criteria .
Statethe requirements for the issue of
-Electrical Installation Certificate . ( EIC )
-Minor Electrical Installation Work Certificate . ( MEIWC )

 

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Q) . where it is necessary to limit the consequences of the risk of fire due tofault-currents . which of the following RCDs is used ?
A) . RCD with operating-current notexceeding 300mA
Q) . What is the maximum operating current for an RCD which may supply portableequipment used outdoors . ?
A) . 30mA . p.54 . 411.3.3. (ii)
Q) . Every electrical installations shall be divided into circuits to . asnecessary to . ?
A) . facilitate safe inspection . testingand maintenance . p.46 . 314.1 . ( ii )
Q) An overload protective device installed at the origin of a circuit must havea breaking capacity of . ?
A) . equivalent or more that the prospective-short-circuit-current .
Q) The maximum disconnection time for a 230V a.c. final-circuit not exceeding32A . with a TT - supply . ?
A) . 0.2 seconds . p.53 . Table - 41.1
Q) In a TT- system . automatic-disconnection of the supply in case of a fault ina 230V a.c. final-circuit not exceeding 32A . ?
A) . 0.2 seconds . p.53 . Table - 41.1
Q) . In a TN-S system . the maximum-earth-fault-loop-impedance ( Zs ) when using a 32A . type B circuit-breaker instantaneous-operation would be . ?
A) . 1.44Ω . p.56. Table - 41.3.

Chapter- 51
510.2. Every item of equipment shall be selected anderected so as to allow for compliance with the regulations in this chapterand other-parts of BS-7671: andManufactures-Instructions .

Q) . A copy of the distribution-board-schedule shall be located with ?
A) . The distribution-board . p.117 .514.9.
Section514 . Identification and Notices .
514.8.Identification of protective-device . Circuit-protective-devices arerequired to be arranged and identified so that the circuit-protected may beeasily-recognised .
514.9.Diagrams . A legible diagram . chart or table . or equivalent form ofinformation . must be provided indicating a range of information .
Q). State . the items that should be included in a distribution chart to meet theabove requirements - 514.9.
Forsimple-installations the information may be given in a . Schedule ( Schedule ofcircuit-details for the installation ) . a durable-copy of which relating tothe distribution-board . shall beprovided within or adjacent to each distribution-board .

 

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514.13.Warning notices . Earthing and bonding-connections .
514.13.1. A durable-label to BS-951 with the words “Safety-Electrical-Connection “ Do Not Remove . shall be permanently fixed in avisible-position at or near .
i)the point of connection of every earthing-conductor to an . earth-electrode .
ii)the point of connection of every bonding-conductor to an .extraneous-conductive-part
iii)the main-earth-terminal . where separate from main-switchgear .

 

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2394: Q ) . Defects identified during aninitial-verification should be ? thisone always comes up .
A) . Made good before the certificate is issued .

Regulation(s), Initial - Verification . p.196
632.4. Defects or omissions revealed during .inspection & testing of theinstallation-work covered by the ( Certificate ) shall be made good before the Certificate is issued .

Q) . An electrical-installation-certificate . must indicate responsibility forthe installation(s) . A ) . Design . construction . testing & testing. p.389 .
(v) ( EIC ) will indicate the responsibility for . design.construction . inspection & testing . whether in relation to new-work . or further-work . on an existing-installation .

Where. design . construction . inspection & testing are the responsibility of one-person a .Certificate with a ( single-signature ) declaration . Etc .

 

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Isolation-proceduresfor Safe-Working .

The only safe-method ofIsolation is by means of an . Individual-locking-device . the system you working on cannot be .energised without the removal of the locking-device .

p.29 . Isolation isdefined as

2394: afunction intended to cut-off for reasons of safety the supply from all . or a discrete-section . of the installation byseparating the installation or section from every-source of . electrical-energy.

Useful-junk

A “ Volt-stick “ is not-considered to be used forsafe-isolation-procedures and can only be . considered to be an ( Indicator that voltage ispresent )

 

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Re-cap .

Functional-tests : GN-3. p.76 . 2394: Table 3.10.2. Testing tobe carried-out where practicable on .Existing-Installation(s) .

Functional-tests of . circuit-breakers . isolators & switching-devices. Manual-operation . to confirm that the devices disconnect the supply

Functional-testing -612.13.1. :

 

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Q) reasons for testing an electrical-installation.

Q) Perform avisual-inspection of any domestic-installation(s) .
Visual-inspection shouldprecede testing .
Reason : Prior to theInstallation being made-live . it is necessary to inspect any part of theinstallation during construction . as these parts . 2394 . in our case . willbe concealed .

 

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Recap .

Can I carry out analteration or addition to an existing-installation that has inadequate-earthing and / or bonding-arrangements .

No - Any alteration oraddition to an existing-installation must comply with the current-edition ofBS-7671: including any amendments . This requires any earthing and bonding-arrangements. upon which the alteration or addition relies for safety to be adequate .

Refer . 132.16. 633.2. 411.3.1.1.

 

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Periodic-Inspection andTesting . ( Careful-scrutiny backed up by testing )

Scenario :
a) . What types ofInspection and Tests . need to be carried-out . Initial-verification for New-work . and Periodic-inspectionand test for the . Existing-installation .

b) Sate : the documentthat should be completed and why
an Electrical-Installation-Certificate for new-work .
Additional-circuitshave been installed and a . Periodic-Inspection for the Existing-installation . ( EICR )

Both of these documentsmust be accompanied with a . Schedule of Inspection and a Schedule oftest-results .

Re-call . p.389 .
vii ) An ( EICR ) willindicate the responsibility for the inspection and testing of an . Existing-installation . within the extentand limitations specified on the report .

viii) Schedules of inspection and Schedules oftest-results as required by part - 6 should be issued with the associated .Electrical-Installation-Certificate . or Electrical-Installation-Condition-Report .

Re-call . p.389 .
Electrical-Installation-Certificateswill indicate the responsibility for design . construction . inspection andtesting . whether in relation to ( New-work ) or further-work on an .existing-installation .

viii) Schedules of inspection and Schedules oftest-results as required by part - 6 should be issued with the associated . Electrical-Installation-Certificate . or Electrical-Installation-Condition-Report.

Periodic-Inspection . Q). if no documentation is available for the installation what action is required. some exploratory-work . to establishthe criteria .

An Inspection and Testis to be conducted on a new-installation . 2394:
State :
a) the type ofverification to be carried out .
b) the documentationthat will need to be completed .

a) Initial-verification.
b)Electrical-Installation-certificate . ( EIC )

* i) Electrical-Installation-Certificate .ii) Schedule of test-results . iii) Schedule of inspection .

a) . if the Ring-final-circuit( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) is0.72Ω . calculate the approximate-reading of ( Zs )
Zs = Ze + ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) = 0.2 + 0.72 = 0.92Ω .

b) . if themaximum-tabulated ( Zs ) for this circuit is ( 1.2Ω ) calculate if the reading in ( a ) isacceptable .

there are nocorrection-factors stated . use the rule of thumb .
1.2 x 0.75= 0.9Ω < 0.92Ω measured . ( Circuit-fails )

c) . State : whatfactors need to be considered before measured .earth-loop-impedance-values are comparedagainst maximum-tabulated ( Zs ) values .
i) .Ambient-temperature-factors . when not measured at 20°C .
ii) .Cable-temperature-factors . not at its operating-temperature .

Record the Test-results.

Ring-Final-Circuit -conductor .
2.5mm[SUP]2[/SUP] T&E cable has a 1.5mm[SUP]2[/SUP] protective-conductor .
In this case multiplythe résistance of the . Line or Neutral-conductor . by a factor of ( 1.67 ) tocross-check the . protective-conductor-readings - 2.5 ÷ 1.5 = 1.67 .

 

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Knowledge ofFundamental-initial-verification . Some handy - revision .

By definition p.29 : Inspection
Examination of an electrical-installation. using all the ( Senses as appropriate )

Q ) . Overloaded-windson a . 3-phase-motor may be identified in the first-instance by ?
A) . Smell .
Sight .
Touch .
Taste .

Q ) . Anearly-indication of an . overloaded-circuit could be found by ?
A) . Using-senses .
Continuity-test .
An insulation-résistance-test.
Anearth-fault-loop-impedance-tester.

Q ) . When diagnosingand locating a . loose-connection the most-effective-sense to use would be ?
A) . Touch .
Smell .
Taste .
Hearing .

2394:
Q) . The safest-methodof making sure an installation is safe to work on would be ?
A) . To follow thesafe-isolation-procedure .

Q) . During an external-loop-impedance-test. the main-earthing-conductor should be ? GN-3 p.53
A) . Disconnected . ( No-Parallel-path )

Q) . An earth-fault-loop-impedance-tester. should only allow-current to flow for . ? GN-3 . p83 / 4.5
A) . 40mS .

Q) . An installationhas a . prospective-fault-current-measured at ( 2.3kA ) and a .prospective-short-circuit-current-measured at ( 2.5kA ) The value that should .be recorded would be ?
A) . The highest .

Q) . Whentwo-bonding-conductors of equal-length .are connected in parallel the résistance would . ?
A) . Halve .
Increase.
Decrease.
Double .

Q) . if the . C.S.A. ofa protective-conductor increases . ?
A) . Résistance-decreases.
Résistance-increases.
The ( Zs ) readings-increases.
Résistance reminds thesame .

Q) . The frequency of .periodic-inspections should be determined by : the type and use of installation. the frequency of maintenance and . ?
A) . Theexternal-influences to which the . the installation is subjected . p.393 / Part - 3 . Essential-Tests .
Q) . Aminor-work-certificate it is not . necessary to record . ?
A) . ( Ze )
Zs .
RCD-operation .
Installation-résistance.

Zs ) . 612.9.Earth-fault-loop-impedance . (Circuit-loop-impedance )
Where protective-measuresare used which require a . knowledge of earth-fault-loop-impedance . therelevant-impedances shall be measured . 2394:

Q) . A minor-work-certificateshall be issued where . ?
A) . An alterationnot-requiring an . additional-circuit is needed .

Q) . it is important to. test an installation in the . correct-sequence-because . ?
A) . Each-test-relies .on the previous to be correct .

 

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Using the wife’sglasses . sorry
Q) . Aminor-work-certificate it is not . necessary to record . ? p.393 / Part - 3 .Essential-Tests .
A) . ( Ze )
Zs .
RCD-operation .
Installation-résistance.

 

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Q) . Theprospective-fault-current at the . origin of an electrical-installation must betaken into account when ?
A) . Selecting the typeof . overcurrent-device to be installed .
Assessing theearthing-arrangement .
Applying-diversity tothe installation .
Estimating the .external-earth-fault-loop-impedance .

Q) . it is a good-ideawhen performing an . insulation-résistance-test on a large-installation . tosubdivide-circuits to avoid ?
A) . False-readingsfrom . parallel-paths .

Q ) . Overloaded-windings on a .3-phase-motor may be identified in the first-instance by ?
A) . Smell .
Sight .
Touch .
Taste .

Q ) . Thenon-statutory-document-concerning the care and use of test-instruments . leadsand probes would by ?
A) . Guidance - Note .GS-38. ( H&S Guidance-note - GS-38 )
Guidance-note - 3 .
BS-7671:2008:2011:
The Electricity at work-regulations 1989 .

Q ) . Aninitial-verification should be carried out on ?
A) . A new-installation.

Q ) . AnElectrical-installation-certificate . must indicate responsibility for the installation’s. ?
A) . Design .construction . inspection & testing . of the work .

Q ) . Electrical-installation-certificate. should be signed by .
A) . A competent-person.

Q ) .BS-7671:2008:2011: has a separate-section or part that is solely-designated to . inspection & testing . this documentis classed as . ?
A) . Anon-statutory-document .

Q ) . Prior to performing-live-tests . &before-energising an installation . you should . ?
A) .Inform-other-people in the area .

 

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Q ) . On preparing to carry out a full-initial-verification . inspection &test on a large-office-block . which of the following items would . be unnecessary at this point . ?
A) . The presence of .inducting-lighting .
The nominal-voltage .
The prospective-fault-current.
The type & ratingof the . protective-device at the origin of the installation .

2394 : as an Inspector.
Q ) . On-disassembling a ceiling-rose-during-completion. of the schedule of inspections on a ( EICR ) you note that ablue-insulated-conductor . is in the Line-terminal . even though thecircuit-work-fine . this might-fail-inspection due to . ?
A) . Identification of conductors.
Polarity-verification .
Connection-method .
Cable-routing .

Q ) . When-testing a ring-final-circuit-protected bya . BS-EN-61009-1 30mA -RCBO . with a RCD-tester at ( x5 ) it should - disconnect ?

A) . Within - 40mS .
Q ) . When-testing at ( 100% ) an RCD -protected-socket-outlet to ( ► BS-7288 ) should operatewithin . ?
A) . 200mS .
Q ) . A . BS-EN-61009-1 30mA RCBO - tested at ( x1 / 100% )should-operate within . ?
A) . 300mS .
Q ) . What-type of test-instrument may give . areading such as ( 16.8mS )
A) . An RCD tester .
** . Q ) . The most-convenient-method of determining thevalue of the . ( PFC ) at the origin of an existing-installation . would be by ?
A) . Measurement .

 

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Q ) . 2394:
After wiring an additional-light-fitting. into a new-conservatory by extending from an ( Existing-circuit ) on completion you should -issue . ?
( MEIEC ) Minor-electrical-installation-works-certificate.
( EIC )Electrical-installation-certificate .
( EICR ) Electrical-installation-condition-report.
Building-control-notification.

Q ) . Before commencingthe . inspection and testing of a new-installation . the information you shouldhave available would be . ?
The . Maximum-earth-fault-loop-impedance. values
The . Earthing-arrangements. ( What do we confirm first )
The . Presence ofany-surge-protective-devices
The . Proximity of theDNO -supply-transformer .

Q ) . Two-ways in whichan electric-shock could-occur are . ?
Direct andfault-contact
A) . Basic andfault-contact
Direct andbasic-contact
Basic and earth-contact.

Q ) . Before commencingthe . inspection and testing of a new-installation . the information you shouldhave available would be . ?
The .Earth-fault-loop-impedance
The . Insulation-résistance-readings for the installation
The . External-loop-impedance. ( Do we have an Earth )
The ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) values of each-individual-sub-main

Q ) . When-performingan . earth-electrode-test . the most-reliable-results . would be when the . distance between the earth-electrodeand the current-spike is . ?
At least ( 5 - times )the maximum-dimension of the electrode-system
At least ( 10 - times )the maximum-dimension of the electrode-system
GN-3 . p.49 . is at least - ten-times .
Between . 2 and 5m away .
Within 2 metres of each-other .

Q ) . During acontinuity of . ring-final-conductors-test . 10-sockets give a ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) reading of ( 0.68Ω ) but one-socket gives a reading of ( 0.92Ω ) this could . indicate . ?
Short-circuit .
High-résistance-fault .
Missing-earth-connection.
Spur on the circuit . ( What would give you a higherreading ) indicating a - Spur . ( 0.92Ω )