rcd problem

[20al]

fitted a 12 way split board in place of old 6 way re wirable. 2 light circs, one ok, other trips rcd. dis board has 2 ways off main switch and 5 ways off each rcd. time was running out so i tried faulty circ on one of the 2 ways off main switch. mcb held but still took out one rcd. i split light circ in two and got half lights working, connected other half and rcd trips, mcb ok. all lights work if rcd is off. before you ask i had already put neutral of faulty circ into main neutral block. Dis board is Contactum , cheap, i know ! any help guys ? cheers.

 

[malcolmsanford]

Borrowed Neutral, neutral to earth fault. dodgy RCD, perm anyone

 

[sparks_114]

The only thing you can really do is carry out an Insulation Resistance test on the lighting to try and find the faulty leg(s). the half that you got working can be left alone, the other half remove all lighting connections and perform IR on each leg and hopefully you'll find the faulty one which you'll have to replace. Hope this helps.

 

[IQ Electrical]

Try both lighting circuits from the same RCD, neutrals in the same bar, that will show you if you have a borrowed neutral (favourite).

 

[Sparky Ninja]

Get the IR tester out and try to confirm separation of circuits, and do as IQ has suggested.

 

[20al]

thanks guys. back there tom and will let you know result.

 

[20al]

twas a borrowed neutral, thanks for help