UK RCD tripping when no load or anything switched on

[Dogstar]

Hi, an Electrician recently replaced all switches, sockets and spot lights. They also appear to have connected an RCD to the fusebox or installed one - I don't know exactly.

However, I now have no power and only a few lights will come on. The RCD is showing as tripped. I can turn all the circuits off and the main switch to try to reset the RCD.

As soon as I put the main switch on with no appliances at all plugged in nor any circuit on so no load, the RCD instantly trips.

I have had carpets fitted upstairs recently and I have noticed one of the spot lights underneath the floor where the carpet was put hanging down.

However, would a damaged wire or appliance only affect one circuit?

If there is no load perhaps the wrong RCD was put in or perhaps the electrician reconnected a faulty RCD. Are any of these possibilities? They tested the electrics after their works and things were working for a while but now not at all.

Thanks for any advice

 

[buzzlightyear]

I would get back the oringial sparks back to have a look at it, there must be a neurtral to earth fault for the RCD to trip.

 

[Strima]

If there's no loads connected to the circuits then it looks like there's damage to your fixed wiring. You will need to get an electrician in to do some fault finding for you.

 

[pc1966]

I think your only sensible option to get it fixed is to get the electrician back to check. It may not be any fault of their work as something might have been damaged by the carpet fitting, light moving, etc, so be pleasant and professional when asking them.

If you can post a photo of your CU (consumer unit = fuse box) with any personal details blanked out then we might be able to suggest things you could try before you can get them back.

Typically if the RCD feeds a few MCB (miniature circuit breakers) you can try switching them all off, and then resetting the RCD. If it trips immediately then it is either a faulty RCD (rare) or a fault between the neutral and earth somewhere (more common and frustrating to diagnosis in many cases).

If it holds when reset, you can then turn on the MCB one at a time, waiting a couple of seconds to be sure between them, and see if one causes it to trip. Switch it off, reset the RCD, and keep going and hopefully you have power to all but the circuit with the live-earth fault seen by the MCB close triggering it.

 

[timhoward]

I think you are saying that with main switch on and every other circuit breaker off the RCD instantly trips.

That being the case it should be fairly quick for an electrician to work out which circuit is causing the instant trip and very likely leave you with more things working. I'd expect that within the first hour.
So as per above I'd try and get original sparks out.

It's not really worth speculating as the cause but most things like this are caused by vibrations shaking a loose connection out, physical damage to a cable, or water somewhere it shouldn't be.

 

[Dogstar]

Thanks for all these helpful responses. The original sparks is coming back tomorrow. He immediately blamed the carpet fitting saying they must have cut a wire when this was reported. When the carpet fitters left the lights were working so it is all a bit puzzling.

I will update the thread with the guy's assessment / advice tomorrow. I will take a picture of the fuse box too if it isn't resolved.

I did notice that a few sockets were still loose and hanging from the walls and I screwed them back in as they should be. Finally before any visits at all from carpet people the people doing screeding complained that they couldn't get power from a socket but then it seemed fine after retrying.

 

[Dogstar]

I think you are saying that with main switch on and every other circuit breaker off the RCD instantly trips.

That being the case it should be fairly quick for an electrician to work out which circuit is causing the instant trip and very likely leave you with more things working. I'd expect that within the first hour.
So as per above I'd try and get original sparks out.

It's not really worth speculating as the cause but most things like this are caused by vibrations shaking a loose connection out, physical damage to a cable, or water somewhere it shouldn't be.

Yes that is exactly what I am saying. I tried an RCD reset based on a YouTube video

 

[LastManOnline]

there must be a neurtral to earth fault for the RCD to trip.

It sounds almost certainly to be a neutral to earth fault. If rcd resets when main isolator and all mcb, s are off then trips when isolator is switched on again its a virtual certainty.
First point is a neutral /earth fault is much harder to isolate than a line to earth fault.
If you have unplugged all appliances (double check) and have switched off all fixed appliances(immersion, undersink water heaters etc) then my next step would be to check for any waterlogged outside lights etc

 

[LastManOnline]

I did notice that a few sockets were still loose and hanging from the walls and I screwed them back in as they should be.

Why were they left loose hanging?. Are you certain all the earth's were properly screened? Neutrals not pressed up against metal boxes etc?

 

[loz2754]

It's entirely possible for it to caused by a wire behind one of the socket fronts that wasn't screwed up properly, to have been caught by the fixing screw, or crushed against part of the metal back box.

edit: beaten to it!

 

[pc1966]

I would be looking very carefully at the sockets, that is the sort of think I have seen before causing grief.

 

[LastManOnline]

edit: beaten to it!

I can assure you... getting there before loz2754 will be recorded in my personal file marked "major personal milestones" ?

 

[timhoward]

I did notice that a few sockets were still loose and hanging from the walls and I screwed them back in as they should be. Finally before any visits at all from carpet people the people doing screeding complained that they couldn't get power from a socket but then it seemed fine after retrying.

With main switch off, you might choose to have a check behind that socket. Might be unrelated or might be best clue yet.

 

[Dogstar]

Why were they left loose hanging?. Are you certain all the earth's were properly screened? Neutrals not pressed up against metal boxes etc?

I don't know. My best guess is the painter unscrewed them to paint around and forgot to tighten again. Hard to say, I was disappointed to find a few like that but a lot were done and it was a minor task to tighten them again. Could the wire be crushed behind it? Or the earth and neutral pushed together? I will direct the electrician to the ones I screwed back.

 

[Pete999]

If there's no loads connected to the circuits then it looks like there's damage to your fixed wiring. You will need to get an electrician in to do some fault finding for you.

 

[Dogstar]

Turned out to be a faulty socket. Original electrician returned for about 15 minutes, showed me how to do the RCD reset correctly and asked me to check behind the sockets I had tightened. 4 of the 5 went back ok but one caused the tripping just when pushed back in and screwed in a bit. Only thing I could see was one of the 3 wires compressed. One brown wire looking a bit worn but should work.

In any case with that socket now hanging out unscrewed and turned off the system works again. Thanks for all suggestions.

Once that socket dealt with / even deactivated then can forget all this nonsense.

 

[pc1966]

It should be possible to get the socket/cable fixed. Always keep sockets, you never have enough!

OK, there is a photo of someone who did have enough on t'Internet somewhere, but for most folks their home always lacks sockets where they really want them.