KITCHEN SOCKETS tripping RCD

[dpm_dpmartin]

Start with a socket on the floor, yes the electrician can test, he will select a random socket likely to be half way, and disconnect the cables, and test which side is down to earth, so he then knows which half the fault is in, and he then splits that half in two, but it is rare for a cable to fail, rodents can cause it, but in the main it is a socket which fails.

He explained something like this in my call with him. Thanks. It makes sense. I suppose no-one cares when they know a socket on the floor is going to be hidden behind a baseboard. He also said it would be a rare case where he needed to do any chasing-out of walls.

 

[ericmark]

I was answering another thread, and I realised for a neutral to earth fault with a TN-C-S supply, it would need less than 2 kΩ to trip the RCD and this can be measured with a standard multi-meter, as only looking at 11.5 volts with worse case scenario. And in your case, since the MCB does not isolate the neutral, extremely unlikely an earth - neutral fault.

So one has to look at the kitchen, and try to work out, likely cable route, and which is last and first socket, and break the ring final. So centre section not connected, so without going into the consumer unit you can test CU to first sockets on the ring final, and the rest. You could do a little more, as you can see.

 

[Harry Bloomfield]

but does it matter if I actually remove plugs from sockets rather than just turned them off?

Probably it does.... A fault L to E, or N to E can cause an RCD to trip, some sockets do isolate both L & N, but they are not common, so to be sure - unplug. Once everything is unplugged, reset the RCD, then plug things back in, one at a time, until it trips - then you have found the cause.

 

[dpm_dpmartin]

Probably it does.... A fault L to E, or N to E can cause an RCD to trip, some sockets do isolate both L & N, but they are not common, so to be sure - unplug. Once everything is unplugged, reset the RCD, then plug things back in, one at a time, until it trips - then you have found the cause.

With everything unplugged the RCD can be set to ON, sure, but once the troublesome circuit is set to ON, the RCD trips once more and the MCB goes to OFF. What you have said here makes perfect sense to me, but what's surprising me is that the circuit in question cannot be set to ON even if nothing at all is plugged in. I have identified all sockets as far as I can tell. All are empty. I am not an Electrician, but I know a little more than the folk who have no exposure to this stuff... I am truly scratching my head as to how this situation arose after years of having no issues whatsoever. It is made more difficult as the Tenants tell me they have done nothing different... but, of course, they would (even if they had been doing something).

I need to pass it to someone else, not a hobbyist like me. I'll find out more tomorrow.