RCD continually trips

Aug 11, 2010 6 Replies

The RCD on the garage circuit is continually tripping, even with everything unplugged.



Divided circuit and with only half the ring connected the trip stayed in. Some things plugged in, still ok. Plugged in freezer (via extension lead) and "pop".



Any thoughts on the sorts of thing to look for? I am planning to break the ring at every socket and test earth continuity, L-E and N-E resistance.


Doesn't the fact that the RCD stays in without the freezer plugged in but trips when it is point to where you should start looking?

Not necessarily because with nothing plugged in when I connected the neutral of half the ring I got a trip. With the other half of the ring only I could get some things to work. I therefore thought half the ring was OK but when I plugged the freezer in it went pop.

I don't disagree that the freezer may be a part guilty party but I think there must be something else. Could it be upstream of the RCD?

Sounds like you've got some 'borrowed' neutrals somewhere. Check that everything on the RCD has its neutral connected to the RCD's neutral, and that everything *not* on the RCD *doesn't*.

The long answer:

formatting link

Have you recently removed any wiring accessories? Check for Neutral being pinched (N-E will cause RCD trip).

Have you got anything outside or conduited to outside on that circuit? Check for water ingress into light fittings, sockets, enclosures, junction-boxes, SWA.

Have you recently nailed or drilled anywhere?

Try all the appliances "as they were" on an extension lead to another circuit's RCD (assuming you have a twin RCD consumer unit which is worth converting to if you just have a non-RCD protected side split load at present).

If you can not pin it down re intermittent you may have to surface wire temporarily to pin it down.

In article , js.b1 writes

Well, the good news is that I found it - but it was in two parts!

A neutral had been hard against a screw holding a cover on and the insulation had given way.

The other problem was in the pump for the pond - it was about 200k L-E and N-E. Thought it was going to be a new pump but discovered the waterproof connector wasn't! Replaced that and we are all working again!

Thanks for all the advice.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required