LIGHTING CIRCUITS. Ask questions and find answers to many subjects relating to electrics and electrical work

[david harris]

Im Installing a new lighting circuit using the loop in method. Every time i go to to switch on the light, it blows and results in tripping the rcd ( which is protecting my sockets). this obviously means ive got a earth leakage problem!!!!!. Can you please advice me on how i can prevent this from happening. Im on a TNCS (PME) EARTHING SYSTEM and it is also new consumer unit. I am all out of ideas, :( [/b]

[pdenni]

hi

Sounds like you have wired the switch cable incorrectly in the ceiling rose/ or fittings, also why is the lighting on the rcd side of the board?

[sparx]

Hi David,
Further to Pdenni's question, which with a PME system I would also ask!
Is it a RCD main sw. or have you a 'split - load' unit? If split - load type is the Neutral in same 1/2 of N bar as Live is on ie Rcd 1/2
regards SPARX

[BLAKEY1963]

[quote="david harris"]Im Installing a new lighting circuit using the loop in method. Every time i go to to switch on the light, it blows and results in tripping the rcd ( which is protecting my sockets). this obviously means ive got a earth leakage problem!!!!!. Can you please advice me on how i can prevent this from happening. Im on a TNCS (PME) EARTHING SYSTEM and it is also new consumer unit. I am all out of ideas, :( [/b][/quote]

DAVE HARRIS
BLAKEY 1963 ERE FIRST OFF ISOLATE SUPPLY AND
REMOVE THE FEED ( THE 3 WIRES FEEDING THIS CIRCUIT )
YOU NEED A SUITABLY COMPENTENT PERSON WHO WOULD BE A QUALIFIED ELECTRICIAN TO PERFORM AN INSULATION TEST ON THE
3 CORES OF THIS CABLE, TESTING BETWEEN PHASE - NEUTRAL
PHASE - C.P.C ( EARTH ) , AND C.P.C TO NEUTRAL.
THIS TEST SHOULD BE DONE WITH ALL LAMPS AND CURRENT USING
EQUIPMENT REMOVED FROM THE LAMP HOLDERS AND THE CIRCUIT ITSLEF( FANS SMOKE ALARMS ECT ).
YOUR TEST BETWEEN ALL CORES SHOULD BE 200MEG OMHS ( 200 MILLION OHMS )
IF NOT THEN YOU POSSIBLY HAVE A FAULT, START WITH LOOKING FOR A NEUTRAL TO EARTH FAULT, BY EXAMINING YOUR TEST READING.