John Rumm wrote:
GMC wrote:
Hi there.

I needed to replace two socket plates in my parents kitchen, i bought
the relevant 2 gang sockets from Screwfix, a brushed stainless Volex
socket which will replace the white plastic ones currently installed.
As soon as I connect either of the new metal sockets the RCD in the
consumer unit trips when the power is turned back on. I have triple
checked that I am connecting it up correctly. The fault goes away as
soon as the plastic socket is reinstated. I initially thought that the
socket may be faulty (!) so used the second one which gave exactly the
same behaviour. It seems that the metal sockets are directly related
to the RCD tripping but I dont understand why, can anyone explain this
to me or offer a solution please? (my solution may be to replace the
sockets with plastic ones!)

If you connect the metal socket, but leave it hanging on the wires and
don't screw it to the backbox, does it still trip?

I take it there have been no other changes other than the sockets? (no
re-wiring etc or new circuits)

Is this a split load CU, or one with a single RCD protecting all the
circuits?

Some metal sockets are quite low profile and hence leave less room in
the box. This can compress the wires more, and also allow the fixing
screws to penetrate deeper. That makes it more likely that any small
nicks in the insulation could cause problems. Check the wires carefully
- especially where they pass into the box (it ought to have a rubber
grommet if its a metal back box to protect the wires - but these are
often omitted)


The socket is earthed exactly the same as it was with the plastic sockets.

The socket does still trip if i leave it hanging on the wires.

The CU is a split load in a fairly new build.

There have been no other changes at all, just the socket swap.

I did notice that there was a rubber grommet where the cable enters the
back box but did not scrutinise the cables for nicks etc.

I dont understand how it works ok with the plastic units but trips with
the metal ones! Google did not have much to say about it either!

Thanks for the help so far.