I&T checklist

[golfpaul]

I'm trying to get my head around inspection and testing.
When I'm struggling, i often find writing it down helps me to learn it - please could you cast your eyes over the below, a little long winded but i would appreciate any altercations or omissions I've made.

Thanks in advance!

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[FONT=Latha, sans-serif]CONTINUITYOF PROTECTIVE CONDUCTORS 2.7.5[/FONT]
[FONT=Latha, sans-serif]CONTINUITYOF RING FINAL CIRCUIT CONDUCTORS 2.7.6[/FONT]
[FONT=Latha, sans-serif]INSULATIONRESISTANCE 2.7.7[/FONT]
[FONT=Latha, sans-serif]PROTECTIONBY SELV, PELV OR BY ELECTRICAL SEPERATION 2.7.8 / 2.7.9[/FONT]
[FONT=Latha, sans-serif]PROTECTONBY BARRIERS OR ENCLOSURES PROVIDED DURING ERECTION 2.7.10[/FONT]
[FONT=Latha, sans-serif]INSULATIONRESISTANCE OF NON-CONDUCTING FLOORS AND WALLS 2.7.11[/FONT]
[FONT=Latha, sans-serif]POLARITY2.7.12[/FONT]
[FONT=Latha, sans-serif]EARTHELECTRODE RESISTANCE 2.7.13[/FONT]
[FONT=Latha, sans-serif]PROTECTIONBY AUTOMATIC DISCONNECTION OF THE SUPPLY 2.7.14[/FONT]
[FONT=Latha, sans-serif]EARTHFAULT LOOP IMPEDANCE 2.7.15[/FONT]
[FONT=Latha, sans-serif]ADDITIONALPROTECTION 2.7.18[/FONT]
[FONT=Latha, sans-serif]PROSPECTIVEFAULT CURRENT 2.7.16[/FONT]
[FONT=Latha, sans-serif]PHASESEQUENCE 2.7.17[/FONT]
[FONT=Latha, sans-serif]FUNCTIONALTESTING 2.7.18 / 2.7.19[/FONT]
[FONT=Latha, sans-serif]VOLTAGEDROP 2.7.20[/FONT]


[FONT=Latha, sans-serif]Thefollowing tests are carried out with the consumersmain switch isolated

1.Extenal earth fault loop impedance
Reason:To establish that a good earth exists at the installation in orderfor the remaining tests to go ahead.
[/FONT]

[FONT=Latha, sans-serif]Methodisconnect the main earthing conductor from the main earthingterminal. An earth fault loop impedance tester is connected at lineand earth (main earthing conductor) at the supply side of theinstallation and a test performed. Reconnect the main earthingconductor. The result is Ze and recorded on the sheet. Theprospective fault current is measured at the same time after thereconnection of the main earthing conductor.

2.Continuity of protective and bonding conductors
Reason:To check that all circuit protective conductors (green and yellowcables) are continuous and are present at every electrical accessoryon the circuit. Also to check that the main earthing conductor andmain bonding conductors are continuous and correctlyconnected.

Method 1: The lineconductor is connected to the circuit protective conductor of thesame circuit at the consumer unit and a measurement taken at ALLaccesories on that circuit between line and c.p.c. The highestmeasurement obtained is recorded on the test report.
Testresult is R1 + R2. The line conductor and neutral conductor are thenconnected and the above repeated to obtain R1 + Rn
[/FONT]

[FONT=Latha, sans-serif]Method2 (used for main earth and main bonding conductors): A wandering leadis connected to one end of the conductor to be tested and ameasurement taken between the other end of this lead and the otherend of the conductor.
Test result isR2.
During this test polarity can bechecked as well. The continuity of the neutral conductor can also bechecked.

3. Continuity of ringfinal circuit conductors
Reason:This test ensures that all ring final circuits (sockets usually) areindeed a continuous ring with no interconnects or breaks withinit.

Method: The line, neutral andearth conductors of the circuit are identified and a measurement fromone end to the other end of each is taken. These results are r1, r2and rn.
The incoming line conductoris then connected to the outgoing earth conductor and the outgoingline conductor is connected to the incoming earth conductor. Ameasurement is then taken at ALL socket outlets on the ring. Thehighest of which is recorded on the report.
Thisresult is R1+R2 for that circuit. The above is then repeated usingthe neutral conductor instead of the earth conductor. This testprovides R1+Rn which does not need to be recorded on the report butis essential to check the circuit correctly.


4.Insulation Resistance
Reason:This test checks whether the insulation around a cable is stillintact and has not broken down over time. It is a good indicator ofthe age of an installation.

Method:An insulation resistance tester is connected across line and neutraltails at the origin of the supply. 500V are then pumped down theconductors to see if any voltage leaks across from one conductor tothe other. The same is then done for the line and earth and the earthand neutral conductors.


5.Polarity
Reason: To check thatall accesories are correctly connected to line, neutral and earth andthat all switches and circuit breakers are connected in the lineconductor only.

Method: Themethod for this is the same as for continuity and is usually done atthe same time by operating switches etc whilst conducting thetest.


6. Earth electroderesistance
Reason: To make surethat any earth electrode used is of a sufficiently low impedance toallow the timely operation of the RCD protecting theinstallation.

Method: An earthfault loop impedance tester is connected between line and earth atthe origin of the supply and a test performed. The result of which isconsidered the resistance of the electrode (Ra).

Thefollowing tests are carried out with the Consumersmain switch energised

7.Live polarity test.[/FONT]
[FONT=Latha, sans-serif]Reason:To verify polarity of supply authorities system.

Method:An approved voltage indicator shall be used or test lamp to GS38.Using the approved voltage indicator, one probe shall be placed onthe incoming neutral, and the other on the incoming line conductor,on the main breaker. The indicator should show it is live. One probeshall now be placed on the CPC and the other on the incoming lineconductor. The indicator should show it is live. A test shall bepreformed between CPC & incoming neutral. The indicator shouldshow that it is not live.

8.Earth fault loop impedance
Reason:This test is done at the furthest point on a circuit in order to makesure the impedance of the earth path is not too high even at thefurthest point so that sufficient current will flow under faultconditions to take out the circuit breaker protecting thecircuit.

Method: An earth faultloop impedance tester is connected to line and earth at the furthestpoint on the circuit and the test performed.

9.RCD test
Reason: To make sureRCD's trip within the correct time

Method:An RCD tester is connected and a test at 1/2 times, 1 times and 5times the trip current is performed on each side of the cycle and atime of trip obtained. Usually milli-seconds with the highest beingrecorded. The manual test button is then pressed.

10.Functional testing
Reason: Tomake sure all switches, isolators, MCB's etc. work as they should.
[/FONT]





















[FONT=Latha, sans-serif]CONTINUITYOF PROTECTIVE CONDUCTORS[/FONT]
[FONT=Latha, sans-serif]TESTMETHOD 1 FOR CIRCUITS[/FONT]


[FONT=Latha, sans-serif]Mainswitch off – Circuit breaker off[/FONT]
[FONT=Latha, sans-serif]L-Elink at CU of circuit under test.[/FONT]
[FONT=Latha, sans-serif]CheckL-E at each point[/FONT]


[FONT=Latha, sans-serif]Resultshould indicate no open circuit[/FONT]
[FONT=Latha, sans-serif]Highestreading is R1 + R2 for the circuit.[/FONT]


[FONT=Latha, sans-serif]TESTMETHOD 2 FOR CIRCUITS[/FONT]


[FONT=Latha, sans-serif]Nullwandering lead[/FONT]
[FONT=Latha, sans-serif]Connectwandering lead to earth terminal at consumer unit.[/FONT]
[FONT=Latha, sans-serif]Testprotective conductor at various points, luminaires / switches / spuroutlets etc.[/FONT]
[FONT=Latha, sans-serif]Highestreading is R2 for the circuit.[/FONT]


[FONT=Latha, sans-serif]Ahigh value indicates loose cpc terminals.[/FONT]


[FONT=Latha, sans-serif]CONTINUITYOF BONDING CONDUCTORS AND EARTHING CONDUCTORS[/FONT]


[FONT=Latha, sans-serif]Usetest method 2.[/FONT]
[FONT=Latha, sans-serif]Resultshould indicate no open circuit[/FONT]
[FONT=Latha, sans-serif]-[/FONT]
[FONT=Latha, sans-serif]CONTINUITYOF RING FINAL CIRCUIT CONDUCTORS[/FONT]


[FONT=Latha, sans-serif]STEP1[/FONT]
[FONT=Latha, sans-serif]Checkend to end resistance of:[/FONT]
[FONT=Latha, sans-serif]LINE– r1[/FONT]
[FONT=Latha, sans-serif]NEUTRAL– rn[/FONT]
[FONT=Latha, sans-serif]CPC– r2[/FONT]


[FONT=Latha, sans-serif]Resistanceof LINE and NEUTRAL should be the same if the conductors are the samesize[/FONT]
[FONT=Latha, sans-serif]Resistanceof CPC should be higher than LINE on NEUTRAL (x1.67 for 2.5/1.5mm2)[/FONT]


[FONT=Latha, sans-serif]STEP2[/FONT]
[FONT=Latha, sans-serif]ConnectL-N / N-L at CU[/FONT]
[FONT=Latha, sans-serif]Checkresistance at each socket outlet, should all be the same.[/FONT]
[FONT=Latha, sans-serif]Valueshould be approx 1/4 of LINE plus NEUTRAL loop resistnce (r1+rn /4)[/FONT]
[FONT=Latha, sans-serif]Spurswill give higher resistance[/FONT]


[FONT=Latha, sans-serif]STEP3[/FONT]
[FONT=Latha, sans-serif]ConnectL-E / E-L at CU[/FONT]
[FONT=Latha, sans-serif]Checkresistance at each socket outlet, should all be the same.[/FONT]
[FONT=Latha, sans-serif]Valueshould be approx 1/4 of LINE plus CPC loop resistnce (r1+r2 /4)[/FONT]
[FONT=Latha, sans-serif]Spurswill give higher resistance[/FONT]
[FONT=Latha, sans-serif]Thehighest reading is R1+R2 for the circuit[/FONT]
[FONT=Latha, sans-serif]Thevalue is used to determine the EFLI (Zs) of the circuit[/FONT]


[FONT=Latha, sans-serif]INSULATIONRESISTANCE[/FONT]
[FONT=Latha, sans-serif]Checkthat:[/FONT]
[FONT=Latha, sans-serif]Theprotective conductor of the item is connected to MET[/FONT]
[FONT=Latha, sans-serif]Pilotlamps/indicators/capacitors removed from circuit.[/FONT]
[FONT=Latha, sans-serif]Voltagesensetive equipment removed, dimmer switches/touch switches/delaytimers/power controllers/electronic starters/rcds.[/FONT]


[FONT=Latha, sans-serif]Disconnectwiring from RCD's/RCBO's, or test with LINE and NEUTRAL connectedtogether, and to EARTH. Start on a low voltage and increase to 500vif gaining satisfactory readings.[/FONT]


[FONT=Latha, sans-serif]IROF WHOLE CU[/FONT]
[FONT=Latha, sans-serif]Mainswitch off[/FONT]
[FONT=Latha, sans-serif]CBon[/FONT]
[FONT=Latha, sans-serif]TestBetween:[/FONT]
[FONT=Latha, sans-serif]NEUTRALbar to incoming LINE[/FONT]
[FONT=Latha, sans-serif]LINEto EARTH[/FONT]
[FONT=Latha, sans-serif]NEUTRALto EARTH[/FONT]


[FONT=Latha, sans-serif]Twoway switching operated one at a time[/FONT]
[FONT=Latha, sans-serif]Forcircuits/equipment vunerable to the test voltage, test with LINE andNEUTRAL [/FONT]
[FONT=Latha, sans-serif]IncomingEARTH connection must be connected to the installations MET (and thatthis is connected to the means of earthing)[/FONT]


[FONT=Latha, sans-serif]IRTEST ON FINAL CIRCUIT[/FONT]
[FONT=Latha, sans-serif]Mainswitch off[/FONT]
[FONT=Latha, sans-serif]CBon[/FONT]
[FONT=Latha, sans-serif]Testbetween:[/FONT]
[FONT=Latha, sans-serif]NEUTRALbar to LINE of circuit[/FONT]
[FONT=Latha, sans-serif]LINEof circuit to EARTH[/FONT]
[FONT=Latha, sans-serif]EARTHto NEUTRAL[/FONT]


[FONT=Latha, sans-serif]SELVAND PELV TEST VOLTAGE 250v MINIMUM IR 0.5M ohm[/FONT]
[FONT=Latha, sans-serif]UPTO500v TEST VOLTAGE 500v MINIMUM IR 1.0M ohm[/FONT]


[FONT=Latha, sans-serif]POLARITYTESTING[/FONT]
[FONT=Latha, sans-serif]Tocheck that fuses and single pole control and protective devices areconnected in the LINE conductor.[/FONT]
[FONT=Latha, sans-serif]Thecentre contact of screw type lampholders must be connected to theline conductor (except E14 and E27 to BSEN60238)[/FONT]
[FONT=Latha, sans-serif]Visuallycheck core colours at terminations[/FONT]
[FONT=Latha, sans-serif] or[/FONT]
[FONT=Latha, sans-serif]Mainswitch off[/FONT]
[FONT=Latha, sans-serif]CBoff[/FONT]
[FONT=Latha, sans-serif]LinkLINE of circuit to EARTH at CU[/FONT]
[FONT=Latha, sans-serif]CheckLINE to EARTH at lighting point or switch for continuity[/FONT]


[FONT=Latha, sans-serif]EXTERNALEARTH FAULT LOOP IMPEDANCE - Ze[/FONT]
[FONT=Latha, sans-serif]Mainswitch off[/FONT]
[FONT=Latha, sans-serif]Disconnectmain earth from CU[/FONT]
[FONT=Latha, sans-serif]Testbetween disconnected incoming EARTH and LINE[/FONT]


[FONT=Latha, sans-serif]AddZe to R1+R2 values to establish Zs for the circuit.[/FONT]


[FONT=Latha, sans-serif]Themeasured value of Zs is compared with maximum Zs x 0.8[/FONT]



[FONT=Latha, sans-serif]EXTERNALLOOP IMPEDANCE – Zs[/FONT]
[FONT=Latha, sans-serif]Measuredat the furthest point on the circuit[/FONT]
[FONT=Latha, sans-serif]Ensureall main protective bonding is in place[/FONT]
[FONT=Latha, sans-serif]Connectto LINE, NEUTRAL and EARTH[/FONT]


[FONT=Latha, sans-serif]PROSPECTIVEFAULT CURRENT – Ipf[/FONT]
[FONT=Latha, sans-serif]Highestreading of PEFC of PSSC recorded on schedule of test results.[/FONT]
[FONT=Latha, sans-serif]Readingis taken at sime time as Ze/s on tester.[/FONT]


[FONT=Latha, sans-serif]RCDtest.[/FONT]
[FONT=Latha, sans-serif]Testfrom socket or CU , connect to LINE, NEUTRAL and EARTH.[/FONT]


[FONT=Latha, sans-serif]FUNCTIONALTESTING[/FONT]

 

[wiganspark]

how about the pressing space button test ?

 

[dazza1981]

how about the pressing space button test ?

AGREED !!!!
That is a painful read !!!
On site guide is helpful ?????

 

[trev]

Why not just read and learn GN3?

 

[dazza1981]

why not just read and learn gn3?

simples !!!!!!!

 

[golfpaul]

No worries, soz to bother ya.

 

[trev]

No worries, soz to bother ya.

It's not a bother mate, it just seems like an awfully long winded way of going about learning it when there's a much easier way.

 

[Richard Burns]

quote/ I would appreciate any altercations or omissions I've made. /quote
Seems like you have made some altercations!

If you ask for help it does make it easier if you have made it as easy as possible for us.

Going through the document in order ignoring spelling (and spacing) errors:

Continuity of protective conductors method 2: the wander lead should be nulled.
Continuity of ring final circuit conductors: the r1+rn is measured but I do not believe R1+Rn is ever used as a symbol.
Insulation resistance Line and Neutral this is not tested at the tails at the origin (very difficult to isolate!) but at the earliest at the outgoing terminals of the main switch.
Earth electrode resistance measured using an EFLI tester is only applicable to TT systems, where accurate measurement is required the full testing is needed.
Earth fault loop impedance is tested to ensure that the protective device will operate in the required time, not just to check the expected current.
RCD testing is to ensure the RCD trips within the prescribed times for that type of RCD and is functional, the 5x test is only performed on 30mA or less RCDs.
Insulation resistance IR test on final circuit the CB should be off or you will test the whole installation.
Polarity testing will be covered by the cpc continuity testing (as mentioned earlier).
External EFLI the reading is compared to the tabulated value in BS7671 * 0.8 to account for the difference in measurement temperature.
Zs is not external it is earth fault. A no trip test should be performed if there is an RCD in circuit.
Prospective fault current, the reading given when measuring Ze is not a recordable figure, the only valid prospective fault current reading will be when the main earthing conductor is connected.
View attachment Inspection and Testing checklist.doc