UKC

Anyone know the most likely reason for the RCD to trip on a domestic circuit. I got up the other morning to find the power off and the RCD tripped. All circuit breakers were intact and nobody had been electrocuted ;o|

Did you have any load on overnight?

Any neutral-earth leakage on any circuit will trip a high load on any circuit. For example I had a fault on the loft ring main (caused by compression of the cable), it was neutral - earth. It only tripped when I used the power drill on the downstairs ring.

You can't diagnose these faults very well yourself though. You'll need a sparky but I would give it another night and see how things go.

In reply to mypyrex: Been doing any DIY or decorating?

We had a similar issue that was caused by bits of plaster we'd disturbed getting into a plug socket; not at the time but a few weeks later. Might be worth checking any sockets close to an area you've been working in if so.

With appropriate safety precautions, of course.

T.

In reply to Philip:
Only a couple of night-lights which are on every night.

In reply to Pursued by a bear:
No but that reminded me of something that happened last year. Smoke alarms went off in the small hours and the only way I could stop them was to turn off at the mains. Couldn't find any obvious cause so I asked the local fire brigade. Couple of chaps came round and asked if we'd had any decorating done recently. As it happened the answer was yes. Apparently paint vapours and dust can set them off.

In reply to mypyrex: Prime causes are kettles and fridges. My next door neighbour had a problem, we unplugged everything then plugged them back in one at a time, it was the kettle lead, tripped even without the kettle attached. Try unplugging everything. Problem is it sounds like it's intermittent.

Good luck.

In reply to mypyrex: Any bulbs blown? That can trip an RCD.

In reply to mypyrex:

The way a RCD/RCBO work is by monitoring the power running through the live also runs through the neutral. If more than 30mA goes into the circuit and it doesn't leave the circuit by the other cable then the circuit has gone down to earth and the RCD/RCBO operates.

what is more likely is that something has got damp and caused the fault or a faulty appliance has caused the RCD to trip.

I'n my opinion it is unlikely that a lamp blowing will cause an RCD to trip. the reason a lamps blowing trips a MCB is because when a current runs through a circuit, the element breaks down and the resistance is lower for a very short amount of time. the resistance dropping increases the current and so the MCB overloads and operates (this is nothing to worry about as most domestic MCB's can withstand a Potentual Fault Current of several 1000 amps)

Hope this helps and isn't to technical for you

Richard

In reply to spearing05:

GU10 halogen spots are notorious for this.

Washing machine is another likely culprit.