Lighting Fuse wire Keeps Blowin

[18leonh]

Please could somebody Try & help me. My girlfriends lighting circuit keeps blowing the fuse wire. Have tested the insulation from the consumer box with a megger & it indicates a short between neutral & earth as well as live & earth. I have taken the outside lights out of the system and checked all light fitting connections (which were tight). The 5 Amp fuse wire explodes apart almost instantaneously with no lights in the on position. Have checked under the floor in the bathroom for any water and its as dry as a dry thing. If any one has any ideas as to where the fault could be or how now to locate it I would be the most grateful man in the world and that means the girlfriend would also be grateful to me...lol

 

[JohnD]

50p says someone has recently changed a light fitting and connected all the reds together and all the blacks together.

Or put a nail through a cable (25p)

 

[Spark123]

How did you do the IR test?

 

[securespark]

When megging the circuit, you have disconnected the cable from the CU?

Your next step, thinking logically, is to break down the circuit into "legs" and meg these individually.

Ie find where the leg from the board to the first light goes and meg it & so on all through the circuit. Do the same with switchwires.

This way you should be able to ID the faulty leg.

Arggggh!!!

 

[Spark123]

Don't forget to remove any dimmer switches and loads/lamps/PIRs etc too. (Remembering to make safe!)

 

[18leonh]

Have changed lights recently yes, but the wires are correct, the circuit worked for about a month. Did the IR test by disconnecting the supply from the consumer unit and removing all the bulbs. Think I will be isolating down the circuit as suggested, I need the girlfriend to be grateful again soooooooon. Many Thanks for your help people.....You Little Beauties

 

[18leonh]

George Michael also says, You gotta have faith. No dimmers or PIRS the circuits....Cheers

 

[sm1thson]

^i dont remember GM talking about dimmers and PIRS!