How do you detect a electrical fault in a lighting wiring circuit. ?

Question

The MCB gets tripped when power is switched on, how do I establish which of the light wiring connection is shorting.

Answer 1

Might not be a short. Could also be an earth fault. Usually ask some sensible questions, and then get the meters out...

What works were done  prior to this fault arising? Not just the electricals, I've seen nails through wires before now.

Answer 2

The commonest cause of MCbs/RCDs tripping on lighting circuits is not a wiring fault at all but a blown bulb causing a short.

Turn all the lights off, turn on at the MCB then turn lights on until you isolate the faulty circuit. The just try removing the bulb and see if that works.

Answer 3

Should really call an electrician, but I'll give you a quick guide.

Ensure all switches are off then turn mcb on. If it doesn't trip turn lights on one by one until you find the faulty one. If it trips immediately Then you must call an electrician, there could be a short in the wiring which could be anywhere in your ceilings, walls or switches or ceiling roses.

Answer 4

If it is the mcb that trips then it is probably a short rather than an earth fault. If the rcd trips then it is an earth fault. Mcbs trip on overload, RCDs on earth current.

Answer 5

it might be a power surge try calling an electrician.If you try on your own you could get electrocuted.If your worried get advice from the experts.

goodbye :)