***Cont../ Useful Information for Electricians & Apprentices***

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2392-10 “ Testing “
Meansfor Disconnecting the Earthing Conductor .

542.4.2. – requires means fordisconnection of the Earthing Conductor . to be provided at or near the ( MET ) of aninstallation to “ Facilitate measurement“ of the Résistance of the Earthing arrangements .

Meansof Earthing “ . Earthing Conductor → [ Bolted Link] → Connections : Circuit protective conductor : Mainprotective bonding conductors :
Functionalearthing conductors – if required : & lighting protection system bonding conductors - if Any .

 

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Inorder to decide whether or not a specific “ Item “ is an Extraneous-conductive-part :

Q). is the item liable to introduce a potential . generally . EarthPotential .
Isthe item liable to introduce a “potential to a person “ or Livestock . who may be in contact with another potential .

Tointroduce a “ potential “ to such a person . the item must not only be apotential . but must be able to “ Introduce the potential “ introduction of the potential requires [ Two-things ]

- Thefirst is that the item [ or a Conducting item in electrical contact with it ] must be accessible to be [ Touched by a part of such a person’s body ]

- Thesecond is that any [ Electrical résistance ] through which the item is connectedto the [ Source ] of its potential – such as the résistanceconnecting an item with Earth potential . must not be so great as to preventthe potential being introduced to a person – due to voltage drop in the résistance.

Isthe item part of the Installation .

Onlyan item which does not form part of the electrical installation concerned may be an [ Extraneous-conductive-part ] however . items serving a purely non-electrical purpose within theinstallation should not be ruled out . moreover . items forming part of anotherinstallation are not precluded .

 

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Thirdpart “ & NOT forming part of the ElectricalInstallation .

Thispart of the definition limits [ Extraneous-conductive-parts ] tobeing items which Do Not From Part . of the electrical installation in question .

Therefore. items which may be [ Extraneous-conductive-parts include ] the following . which are referred to inRegulation – 411.3.1.2. with regard to “ Main Protective bondingconductor “ provided such items arealso covered by other parts of the definition referred .

Waterinstallation pipes .
Gasinstallation pipes .. Etc .

Anyother non-electrical items which fallwithin the definition may be Extraneous-conductive-parts .
Althoughthe definition precludes items forming part of the electrical installation frombeing Extraneous-conductive-parts .items . serving a purely non-electrical purpose within an electricalinstallation should NOT be ruled OUT . such items may include .

A Metalsupport system or carrier for cables having non-metallicsheaths which is not required to be earthed .

Moreover– items forming part of another electrical installation – that is . aninstallation supplied from a different origin or having a separate earthing arrangements .
Are not precluded from being . Extraneous-conductive-parts . such items mayinclude . for Example . a metal conduit or the metal sheath or armouring of acable entering the premises from another building .

 

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SpecialInstallations or Locations : 2011:

Theuse of SELV.

701: locations containing a bath or Shower .

701.414. Protection against electric shock .
701.512.3. Erection of switchgear . control gear &accessories .
701.55. Current – using equipment .
701.753. Electric floor heating systems .

702. Swimming pools . Application ofprotective measures against electric shock .

702.414. Protection against electric shock .
702.522.24. Junction boxes .
702.53. Switchgear & controlgear .
702.55. Other equipment .

703. Hot air saunas . Protection against electricshock .
704. Construction & demolition siteinstallations . 704.410.3. - 704.414. Protection against electric shock .
705. Agricultural & horticultural premises . 705.414. Protection against electricshock .
706. Conducting locations . 706.410.3.10. Protection against electric shock .

711. Exhibitions . shows & stands . 711.414.4.5. . Protection againstelectric shock .
712. Solar photovoltaic ( PV ) power supply systems . 712.414. Protection against electricshock .

 

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Emergency Lighting :

Checklist .

For Emergency Lighting .
Non-Maintained . -&-s . The light only operates whenthe [ Normal main supply fails ] Emergency Lighting only .
( Permanent L ./ N )

Maintained . -&-s. The lighting operates normally & continues to operate when the normalmains supply fails [ Mains lighting& Emergency lighting ]
( Switched L : Permanent L . / N )

Final Exit Sign’s:
To provide illumination of escape routes .

Junctions : Install within 2 metres of escape route junctions .

Corridors : Install within 2 metres . horizontal distance of achange of direction in an escape route .

Stairways : Installwithin 2 metres . horizontal distance of achange in floor level or stairs [ each tread to receive direct light ]

Final Exit : Install externally within 2 metres horizontal distance of any final exits . Note : that sufficient light will be needed tomuster a roll call .

Alarm Exit : Firealarms . first aid points & fire fighting equipment . installed within 2metres horizontal distance .

Escalators : Shouldnot be used as an escape route . butrequires the same illumination to protect Uses on it when the supply fails .

Toilets : Install in all toilets exceeding [ 8m[SUP]2[/SUP] ] area or where natural light is not present .

Lifts : Toprovide emergency illumination in alllifts .

Control Rooms : Motorgenerator . control & plant rooms for essential & safety services .

Open Areas : Open rooms either with a particular hazard . an escape route passing through or largerthan [ 60m[SUP]2[/SUP] ]

Hazardous Areas : Areas of high risk should beilluminated to [ 10% ] of normal lighting or [ 15 lux ] whichever is greater .

Lighting Requirements .
When luminaires have been sited to cover the locations[ Above ] ▲ additional luminaires may be required toensure minimum lighting levels areachieved .
Manufactures provide spacing tables for this purpose . Spacingtables advise how far to locate the first luminaire . then how far . apart otherluminaires should be located for a given mounting height . Installation to the spacing’s will ensure thelighting levels will be achieved .

Escape route corridors : 1 lux minimum on the centre line of the escaperoute .
Open Areas : 0.5lux minimum on the centre core to within 0.5m of the walls .

Exit signs : Signs should apply to the European SignsDirective & be either . back illuminated or have an Emergency luminairewithin 2m of horizontal height . Signs should be of thesame formal throughout the building .

 

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Emergency Lighting :
Form . EmergencyLighting design guide . 4 Edition 2008 .

Workplace directive – 89/654 .
Is 5 or more people areemployed there must be a writtenrecord of the assessments findings & the action taken . -&-s Exams

Maintained Emergency Luminaire :
A Luminaire containing one or more lamps all of whichoperate from the normal supply . or fromthe emergency supply at all material times .

Non - Maintained Emergency Luminaire :
A Luminaire containing one or more lamps . whichoperate from the emergency supply ONLY upon failure of the normal mains supply.

Normal Lighting :
All permanently installed [ Artificial ] lighting operating from the normal electricalsupply that in the absence of adequate [ daylight ] is intended for use duringthe whole time that the premises are Occupied .

Rated duration :
The manufactures declared duration . specifying the time for which the emergency lightingwill provide the rated lumen output after mains failure . this may be for anyreasonable period but in normally [ one or three hours . ] -&-s Exams

Rated Load : Themaximum load that may be connected to the system & will be supplied for theduration .

Re – charge period :
The time necessary for the [ Batteries ] to regain sufficient capacity to achieve their ratedduration .

Self – contained emergency luminaire or Single point luminaire :
A luminaire or sign . providing maintained or .Non-maintained emergency lighting in which all the elements such as the battery. lamp & the control unit are contained within the housing or within one metre of the housing .

Slave or Centrally supplied luminaire :
An emergency luminaire without its own batteriesdesigned to work with a central battery system .

 

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Usefuljunk :

EdisonBase – Light Bulb’s . 612.6. (ii) [ Indicates ] 230V / E27 . male screw base.
E27 . the number “ 27 “ simply signifiesthe number of millimetres in diameter of the base itself . [ 27mm ]

 

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Zones : Previous 16[SUP]th[/SUP] Edition .
Identifiedzones within the bathroom to [ Illustrate] what typeof electrics in the Bathroom . can be usedor installed .

Zones: 17[SUP]th[/SUP]Edition . “ Updated “

Takeinto account . Windows : doors : walls ceiling & partitions . [2392-10 - You are . Assessing the level of Risk in each Zone ]

Circuits in a Bath or Shower room . both power & lightingmust be Additionally protected by an RCD . 30mA - 701.411.3.3.: 314.1 (iv) : 531.2.4. Unwanted tripping .

17[SUP]th[/SUP]Edition – reinforces this .
Bath or Shower islocated in a building with Protective equipotential bonding in place . 411.3.1.2.

Mainprotective bonding conductor(s) . (i) Water installation pipes . [ Extraneous – conductive– parts ]

p/27 . Equipotential bonding. Electrical connection maintaining various . Exposed-conductive-parts & Extraneous-conductive-parts

• 2392-10 : Exams

Inyour own words . State . the meaning of a circuit overload & short-circuit protection . What will provide this type of protection !! :icon_bs:
p/35 . RCBO .

Wording .
Residualcurrent operated switching device . designed to perform the functions ofprotection against [ Overload & / or Short-circuit]

 

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Bathroomequipment . selection & erection requirements .

Equipmentin “ Zone 1& 2 “ shall be at least IPX4 . Regulation . 701.512.2.( ii )
Equipmentin “ Zone 0 “ shall be at least IPX7 . Regulation . 701.512.2.( i )
Equipment exposed to cleaning jets to be at least IPX5. . Regulation . 701.512.2.

Zone 0 “ only 12V currentusing equipment . complying with a relevant standard is allowed . 701.55 .
(ii) - Fixed & permanently connected .
(iii) - SELV . safety source located outside of Zone .

in Zone 1 “ only :

Water/pumps. electrical shower(s) . Shower/pumps . ventilation equipment . towel rails . waterheaters . luminaires & 25V - SELV equipment is allowed . 701.55.
Fixed& permanently connected . SELV safety . source located outside of Zone . 0. 1. & 2 .

in Zone 2 “ only :

12V. SELV switches & shaver supply .socket-outlets to BS-EN-61558-2-5 . are the onlyallowed switchgear or accessories . 701.512.3.
SELV. safety source located outside of Zone .

2392-10: IP rating. dependent upon it’s location in the room . :banghead:

 

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GN-3– 2012 :

Classification of danger & non-compliances ( foruse during periodic inspection & testing )

Classification of danger or non-compliances [Description ]
C1: Danger present . Risk of injury . immediateremedial action required .

Notes &guidance :
To be cited insituations which cannot be left . it is suggested that these are rectified orpossibly . isolation may be recommended or necessary . examples : includeaccessible bare live parts , badly damaged equipment with risk of access tolive parts . incorrect polarity . arcing found in switchgear .

C2: potentially dangerous – urgent remedial action required .
To be cited insituations that . whilst urgent , do not require immediate remedial action . .examples : include a non-earthed installation . ( this requires a further faultto manifest injury ) fundamentally undersized cables . earth loop faultimpedance values greater than ( BS-7671) requirements . a “ borrowed “ neutral . equipment with inappropriatelyselected IP . ( this may be . C1 if severe ) insulationreadings under ( 1MΩ )connections not terminated within appropriate enclosures .

C3: Improvements required .
To be cited where .C1 or C2 . do not apply . examples : include the absenceof most warning notices . absence of therequired diagrams & charts . no or incorrect marking of conductors atterminations , absence of an ( RCD ) specified for additional protection . ( Where the circuit otherwise tests as normal )

 

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GN-3– 2012 : ( IR )

InsulationRésistance of a . Three-phase 4– core power cable .
The cable is tested.

Insulation Résistancetest on . 4-core power cable :

Test 1 : L1 / L2 .
Test 2 : L1 / L3 .
Test 3 : L2 / L3 .

Test 4 : L1 + L2 +L3 – ( connected together ) to Neutral
The lowest value ofthese tests . is recorded as “ between Live conductors “

Test 5 : L1 + L2 + (connected together ) to Earth .
The lowest value ofthese tests . is recorded as “ between Live conductors & Earth “

Note :it is essential for . Tests 5 & 6 that the cable earth is connected to the installation earthing terminal.

( IR ) readings obtained should be not less than theminimum values referred to table.BS-7671:2011 . Table61 .

 

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GN-3– 2012 : ( IR )

612.4.1. : SELV tests .
Test type .

Basic insulation .between Line conductors & all other circuits including other . SELV &PELV . & low voltage circuits . ( 250V – d.c.) Minimum – 0.5MΩ .

Line / Earth : Between al SELV live parts & Earth .

Note: in situations where the SELV conductorsare separated by just ( insulation ) such as within a ( multicorecable ) with low voltage circuits . then the test voltage shall be increasedto ( 500V d.c.) & the (IR ) shall be not less than . ( 1MΩ )

612.4.2. : PELV tests .
Test type .

Basic insulation .between Line conductors & all other circuits including other . SELV &PELV . & low voltage circuits . ( 250V – d.c.) Minimum – 0.5MΩ .

Note: in situations where the PELV conductorsare separated by just ( insulation ) such as within a ( multicorecable ) with low voltage circuits . then the test voltage shall be increasedto ( 500V d.c. ) & the ( IR ) shall be not less than . ( 1MΩ )

 

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Teatmethod 2 : for circuits .

Instrument : use a low-résistance ohmmeter for test . ◄► Exams – 2391-10 .

One lead of thetest instrument is connected to the earth terminal at the distribution board . via a length of test cable or ( Wandering Lead ) the other test lead is used to make contactwith the protective conductor at . various points on the circuit under test .e.g. luminaires. switches . spursoutlets . etc . the résistance ofthe ( Wandering Lead ) & the test leads areeither auto-nulled prior to making the test ormeasured & subtracted from measured readings .

This test measuresthe continuity résistance of the circuit protective conductors ( R[SUP]2[/SUP] ) which should be ( Recorded on the Scheduleof Test Results )

Note: Parallel earth paths & effects on thereadings ) ◄► Exams – 2391-10 .

Exams – 2391-10 . Wording : Mainswitch [ OFF ] all fuses removed . circuit/ breakers [ OFF ]

Results : for test method 2 :

The results shouldfirst & foremost indicate ( No Open Circuit ) in the protective conductors . for insulatedwiring systems installed in conditions where accessory boxes & similar are not connected tofabric or other elements that mat be earthed . then the measurement will equate to the protective conductor résistance ( R[SUP]2[/SUP] ) this test can detect poor continuity atjunctions & connections since . for a New installation with new accessories. the contribution of résistance of healthy connections is negligible & canbe ignored . thus by employing the résistance data for copper conductors .

Expected values forhealthy cable & connections can be checked .

Example . Radialcircuit . of length about . 55m with a 2.5mm[SUP]2[/SUP] copper protectiveconductor should have an ( R[SUP]2[/SUP] ) résistance .
Length of circuitis 55m .
Résistance of cableis . 7.41 mΩ/m - at 20°C .
Theoretical minimumd.c. résistance- ( 55 x 7.41 ) / 1000 = 0.41 Ω

When verifying this circuitthe . Inspector . should be looking for a reading of that order . say . 0.4 to 05Ω . if the circuit had several outlets . thusmeasuring that the protective conductor was broken & connected in screwterminals at each accessory . then a slightly higher value may be measured . asthere would be some résistance at the termin

 

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( IR ) Testing . 2392-10 . / 2394 .Exams . Q/As .

For circuits containing [two-way switching or two-way & intermediate switching ] the switches must be [ operated one at a time] at a time & the circuits subjectedto additional ( IR) test in these configurations .

 

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Testing . .

Earth fault loop impedance: Verification . 612.9.

Where limitation ofearth fault loop impedance is part of a protective measure .then it is fundamental that the [ InitialVerification ] process includesverification of earth fault loop impedances .

The earth faultcurrent loop comprises the followingelements . starting at the point of fault on the line – earth loop .
Circuit protective conductor.
Main earthingterminal & earthing conductor .
TN-system’s the metallic return path or . in the case of . TT & IT . systems .the earth return path .
Path through theearthed neutral point of the transformer .
Source line windings . &
Line conductor fromthe source to the point of fault .

612.8. - 612.9. :
There are [ Two-methods ] used for verifying total . earth faultloop impedance for a circuit :

- Measurement oftotal earth fault loop impedance ( Zs )using an instrument .
- Measurement of ( R[SUP]1[/SUP] + R[SUP]2[/SUP] ) during continuity testing of a circuit . & addition to the measured earth faultloop impedance external to that circuit ( Ze )

Exams . Instrument : use an earthfault loop impedance tester . for this test .

 

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Testing . .

ElectricalInstallation Condition Report . ( EICR )
634.1.
Amendment No 1 –BS07671:2008 . reporting of periodicinspection & testing .

Full . ( EICR) documentation comprises .

ElectricalInstallation Condition Report .
&
Schedule ofInspections ( one or more )
&
Schedule of Test results . ( one or more )

Exams : On completion of . periodic inspection &testing . this ( EICR ) & itsaccompanying . Schedule of Inspections .& Schedule of Test results . mustbe given to the . Client or Person . who ordered the Inspection .

634.2.
A most importantpoint to . remember is that any damage . deterioration . defects . Part 2- dangerous conditions &non-compliance with BS-7671: that may give rise to danger ( danger being a riskor injury to persons or livestock ) mustbe recorded on the report .

 

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Testing . . 2392-10 . Exam’s Q/As

EarthFault Loop Impedance Testers:

ETC. : To minimise . Electric Shock . hazard from the potential of the protectiveconductor . the [ Test durationshould be within safe limits ] this means that the . instrument should cut [ OFF ] the test current after [ 40mS ] or atime determined by . the safety limits .

EarthFault Loop Impedance Testers: Exams : BS-EN-61557-3 .

 

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InitialVerification – ( Inspection & Testing ) forms .

Following an . InitialVerification . or [ Additionor Alteration to an ExistingInstallation ] an (EIC ) is required to be completed &issued together with . InspectionSchedules . & Test results Schedules.

There are twooptions . for ( EIC ) provided . form 1 : or form 2 : .

Form 1 : - Shortform of ( EIC ) to beused when . ONE person is responsible for the. design . construction . inspection & testing of an installation .
Or
From 2 : - ( EIC ) Three signatoryversion . from appendix 6 – BS-7671 .

Whichever . ( EIC ) isused . appropriate numbers of the following forms are required to . accompanythe Certificate .

Form 3 – Schedule ofInspections’ .
&
Form 4 – Generic . Scheduleof Test results .

For completeness .two samples of typical completed from 4s [ Schedule of test results ] areincluded . One . being for a Single-phase installation . & the other for a Three-phase installation .

2392-10 . this isthe kind of things -&-s will beasking you . ▲ which for ? . Single-phase / Three-phase installation.

 

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Point . to note: p/389 . Certification & Reporting .
( x ) Additionalforms may be required as . clarification . if needed by . Ordinary persons . or inexpansion . for larger or more complex installations .

 

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( MEIWC)
Two thing spring tomind . -&-s . 2392-10

The . Minor WorkCertificate . is intended to be used for . Alterations or Additions . to an [ Installation thatdo not extended to the provision of a NEW Circuit ]

This Certificatemay also be used for the .
replacement ofequipment such as accessories or luminaires , but not for the replacement of . distributionboards . or similar items . [ Appropriateinspection & testing . however . should always becarried out irrespective of the extent of the work undertaken . ] -&-s

 

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( MEIWC)

Description of ( MWs)

The minor work mustbe so described that the work that is the subject of the Certificate . can bereadily identified .

120.3. & 133.5.
No departures areto be expected except in most . unusual circumstances . 633.1.

Installationdetails .
Method of faultprotection must be clearly identified .Automatic disconnection of supply . ADS

If the existinginstallation lacks either an effective means of earthing or adequate . mainequipotential bonding conductors . this must be clearly stated in the spaceprovided – 633.2.

Recorded departures. form BS-7671 . may constitute . non-compliance with the . Electricity Safety. Quality & Continuity Regulations – 2002 . as amended . or the Electricity at Work Regulations 1989 . it is important that the Client isadvised immediately in Writing .

Essential Tests .
Relevant provisionsof part 6 . Inspection & Testing –BS-7671 . must be applied in full to all ( MWs )

Where asocket-outlet is added to an existing circuit . it is necessary to :
i) establish that the earthing contact of thesocket-outlet is connected to the ( MET)
ii) measure the ( IR ) of the circuit that has been added to . &establish that it complies with Table 61 .
iii) measure the EarthFault Loop Impedance . to establish that themaximum permitted disconnection time is [Not Exceeded ]
iv) Check that the polarity of the socket-outletis correct .
v) if the work is protected by an . RCD . verifythe effectiveness of the ., RCD .

 

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Inyour own words state what we mean by “ Basic protection “ & how is itachieved :

GN-3. 2012
Basic protection .
Sect– 416 . 416.2.
Ismost usually provided by [Insulation ] & or [ Enclosures ] the inspection of this measure is to check that insulation has not beendamaged during installation & that [Enclosures ] have been selected for atleast . IPXXB or IP2X .& for top surfaces . at leastIPXXD or IPX4 . & are not damaged .

(IR ) is of course a fundamental test to be carried Out .

 

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Inyour own words state what we mean by “ fault protection “ & how is it achieved .

Faultprotection by ( ADS )
Summaryof RCD requirements :
AnRCD should be cable of disconnecting allLine conductors at substantially the same time .
AnRCD cannot be used for fault protection on it’s own .

AnRCD on it’s own does not provide protection against overcurrents .
Overcurrentprotection is provided by a [ fuse or miniature circuit breaker – MCB] Exams’ . Combined :- RCD & MCB . RCBOs

RCCBs. BS-EN-61008-1 . p/34 .
Residual current operated circuit/breaker . [ Without integral overcurrent protection] for it’s time – household &similar uses

RCBOs. BS-EN-61009-1 . p/34 .
Residual current operated circuit/breaker . [ With integral overcurrent protection ] – household & similar uses .

Basicprotection : can be achieved by either preventing the current from passingthrough a body or by limiting the valueof the current to a non-hazardous level .
Faultprotection : can be achieved by similarmethods . but also by reducing the time the body is exposed to the fault .therefore aiming to reduce the time to a non-hazardous level .

Theprotective measure available :

Automaticdisconnection of supply – ( ADS )

Basicprotection 411.2.: can be achieved by either preventing the current from passing through a body or by limiting the value of thecurrent to a non-hazardous level .
To achieve basic protection the electrical equipmentmust rather employ the requirements of basic insulation of Live parts . – 416.1. :

Live parts . such as energizedconductors . must not be accessible . &
Conductiveparts . which are accessible suchas “ Metal pipes “ must not be hazardous Live .

 

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610.1. it should be noted the regulation 610.1.requires inspection & testing to be carried out during the erection stageof the installation . as well as on completion .

132.14.1.
Verification ofPolarity : Single-pole device in a TN- or TT system .
530.3.2:
Must be verifiedthat . single-pole devices for protection or switching are installed in lineconductors only .

Inyour own words state what we mean by “ fault protection “ & how is it achieved .

GN-3 :
Fault Protection .
The various methodsof fault protection are classified in a number of [ subsections ] BS-7671 -

Sect 411 . –418.1.
Automaticdisconnection of supply – ( ADS )
Method 1 : ( ADS )
For each circuit .automatic disconnection is required & . although the main part of .Verification is measurements of earth fault loop Impedance in order to confirm sdisconnectiontimes . there are inspection aspects to consider for verifying ( ADS ) follows :

2392-10 .
542.3. Earthing conductor .
Sect – 543 .Circuit protective conductors .
Sect – 544 .protective bonding conductors .
- Mainbonding conductors .
- Supplementary bonding conductors . where required.

312.2. The earthing system must be determined .
TN-C-S . - Protective multiple earthing – ( PME )
TN-S system .
TT system – Earth Electrode(s).

 

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Fused connectionunit :
Correct rating& fuse – 533.1.
Complies withBS-1363-4 – 559.6.1.1. – vii .

Cooker control unit.
- Sited to one side& low enough for accessibility & to prevent flexes trailing across radiant plates – 522.2.1.
- Cable to cookerfixed to prevent strain on connections – 522.8.5.

Test Method 2 : (R[SUP]2 [/SUP] )
Test Method 1: ( R[SUP]1[/SUP] + R[SUP] 2 [/SUP])

Radial circuit oflength about 55m with 2.5mm[SUP]2 [/SUP] Line & protective conductors should havean ( R[SUP]1[/SUP] + R[SUP] 2 [/SUP]) résistance .
Length of circuit –55m
Résistance of cableis . 7.41 mΩ/m ( at 20°C)
Theoretical minimum d.c. résistance = ( 55 x 2 x7.41 ) / 1000 = 0.82Ω

 

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Additions &Alterations .

132.16. Every addition & alteration to an existinginstallation must comply with the current edition of BS-7671 . & must notimpair the safety of the existing installation . in this respect . in order to verify that the addition & alterationto an electrical installation complies with BS-7671 . the existing installation must beinspected & tested to confirm the safety of the addition & alteration . 633.1. 633.2.

- Protective conductorcontinuity .
- Earth fault loopimpedance .

633.2. Whilst there is no obligation to inspect & test any part of the existinginstallation that does not affect & is not affected by the addition & alteration. observed departures are required to be noted in the comments box . of ( EIC ) single-signature . or multiple-signature . &minor work certificates .

 

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Recording the .Prospective Fault Current . ( PFC )

Both the ( EIC ) & the ( EICR ) contain a box headed . Nature of Supply Parameters . . whichrequires the . ( PFC ) at the [ Origin ] to be recorded .
The value to berecorded is the . Greater of either the short-circuit current . – between liveconductors . or the earth fault current . between line conductor(s) . & the. ( MET )

if it is considered necessary to record values atother relevant points . they can be . recorded on the . Schedule of Test Results . where the protective devices used . at theOrigin have the necessary rated breaking capacity . & devices with similar breakingcapacity are used throughout the installation . it can be assumed that theregulations are satisfied in this respect for all . distribution boards .

 

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PhaseSequence Testing . 612.12.

Thiscame up on Exams . 2391-10 ..

The 17[SUP]th[/SUP] Edition . introduced inregulation – 612.12. a requirement to [ Verify ] that the . phase-sequence ismaintained for multiphase circuits within an installation . in practice . thiswill be . achieved by checking polarity & connections throughout theinstallation .


Optionally& occasionally . the inspector may wish to . check phase sequence by usinga phase rotation tester . either .
- Rotating disk type . Or
- Indicator lamp type .

 

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Verification in Medical Locations . 710 :

710.61. The installation & testing of theseinstallations is very much a . specialist area & only the general requirements of .BS-7671 . are provided in this GN- .initial verification is carried out by an inspection & functional tests ofthe isolation IT system . equipment including the . insulationmonitoring devices . testing is required to measure the . leakage current ofthe output circuit of . Medical IT isolating transformers . & measurementof the résistance of the . supplementary equipotential bonding .

 

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Purposeof . Periodic Inspection & Testing . 621.2. is to provide an Engineering view . on whether or not theinstallation is in a satisfactory condition where it can continue to be usedSafety .

 

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Purposeof . Periodic Inspection & Testing . 621.2. is to provide an Engineering view . on whether or not theinstallation is in a satisfactory condition where it can continue to be usedSafety .

Itshould be noted that the initial . sample size is only based on a . walk-round .& consultation of . records . further . that what may at first appear to begood . E.g. the quality of maintenance . may turn out to be poor during the detailed inspection & testing .

Suggestedprocedure for setting . Initial & adjusted sample size .

Conductinitial “ Walk round “ survey &establish initial sample size .
▼
Carryout Inspection & Testing . based on initial sample size .

▼ Good results .
Goto final report .

▼ Intermediate/ poor results .
Increasesample size . or discuss with Client . whether further investigation is required .

 

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Stillthe same . 2391-10 :

Low-résistanceohmmeters . BS-EN-61557-4 .
(IR ) testers . BS-EN-61557-2 .

Earthfault loop impedance testers . BS-EN-61557-3 .
Thismeans that the instrument should cut OFF the test current after [ 40mS ] Etc .

(RCD ) testers . BS-EN-61557-6 .
Reminder . 2392-10 . -&-s
Tocheck RCD . operation & to minimise danger during the “ Test “ the test current should be appliedfor no longer than [ 2s ]

Phaserotation instruments . BS-EN-61557-7 .
Exams: Mechanical . visual & / or audiblemeans .

 

[Dan]

I'm just bumping some of the older threads in the general electrical forum that had a lot of replies. They might not be current topics, if they're not, just ignore them and they'll soon drop off the list. If you DO wish to add a reply and get the conversation going again, feel free to do so. Your input might help somebody else in the future.

 

[Dan]

I'm just bumping some threads in the Electrical Forum, don't mind me while I do this, you don't have to respond to them. Although if they are still current topics, and you do wish to reply, you're welcome to. Keep the thread on-topic and make sure you stick to the forum rules though.