hi i have had a new split load consumer unit fitted and the rcb trips out when power is switched on.if you switch off the socket ring main the rcb is ok what i find strange is the fact that the ring main is on the other circuit so power to it is not going through rcb any ideas electrician said major fault finding needed

rob, May 2010

sound like the neutrals in the ccu i.e fuse box are not in order ? the cable on the rcd side have a neutral bar and only rcd moniterd neutrals are conected too it if this is not connected correctley the rcd will trip . sounds like the ring main neutrals are on the wrong neutral bar . hope this helps. if in any doubt contact a qullified electrican

steve, May 2010

The RCD (Residual Current Device) compares the current difference between live & neutral - for some reason - undoubtedly a wiring fault - your RCD is detecting a difference - it may be a neutral return not going to the place it should go to - you should complain to the person who fitted it and have a qualified person inspect it and give you a safety inspection certificate.

Peccavi, May 2010

Is there anything in the 'Observations and recommendations' box on your inspection report?

It sounds like the fault is on one of the power circuits; I would start by testing those.

Adam, May 2010