RCD on my Consumer Unit Tripping

[JtB]

The RCD on my consumer unit seems to be randomly tripping.

By process of elimination I’ve identified a number of circuits and appliances which are not at fault but it’s proving quite difficult to home in on the actual problem due to the intermittent nature of the tripping.

Last time it took 12 days for the RCD to trip and it’s always the main RCD that trips and not the MCBs protecting the individual circuits. Last time the RCD tripped it took several attempts to reset it. On each attempt I switched off a different MCB until I was able to reset the RCD, but I don’t know if that identified the circuit causing the problem or if it was just coincidental because I was then able to switch back on that MCB again without the RCD tripping.

Any advice on next steps would be very much appreciated as I’m starting to draw a blank.

Many thanks.

 

[Electric_Andy]

Have you got any outside lights or sockets? Could it be weather dependant? Have you got any switches or sockets where the housing is loose? Otherwise, the only way to really tell is to get a proper testing tool, and that might be hit or miss. We have a socket behind the TV that doesn't work (or at least doesn't work enough to turn the TV or a light on), but works on a small draw like charging a phone. Even the electricians had never had that code before when they checked, and they couldn't tell us why it worked a bit but not properly. If something is badly wired or badly earthed then it could be tricky.

 

[Over the Ord]

My mothers RCD would trip at random time, we eventually discovered that system couldn’t handle the washing machine, cooker and iron all on at the same time.

 

[T4tomo]

The RCD on my consumer unit seems to be randomly tripping.

Which indicates there is a fault somewhere (albeit intermittent), so get a sparky in to check it.
Could be a fault with the RCD switch itsself, or a loose connection. Loose connections lead to shorts & sparks which lead to fires....

 

[N0bodyOfTheGoat]

Two or more high Watt/Amp kitchen items on the same double socket, that only sometimes are turned on at the same time?

 

[DRM]

Which indicates there is a fault somewhere (albeit intermittent), so get a sparky in to check it.
Could be a fault with the RCD switch itsself, or a loose connection. Loose connections lead to shorts & sparks which lead to fires....

This is a known thing, I've seen sparkies in factories/warehouses that have been sent in to check the distribution boards on behalf of the insurers, part of that is taking a picture with a heat sensing camera that highlights any breakers that are running hot, they can then fit a replacement, the one I saw was actually red hot, and the bloke swapped it out that day, but to all intents & purposes was functioning correctly

 

[Mr Celine]

RCDs and MCBs protect against different types of fault. The former trips if there is an imbalance between the currents in the live and neutral wires and the latter trips if the current is too high.
Switching off MCBs one by one until the RCD reset may have identified the guilty circuit. What appliances are plugged into that?

IANAE

 

[raleighnut]

Our RCD used to trip out for no reason, turns out it was farked...................luckily we had insurance from having a shower installed as the RCD was obsolete so the whole board had to be changed, couple of grands worth of parts and labour.

 

[T4tomo]

Our RCD used to trip out for no reason, turns out because it was farked.

FIFY

 

[raleighnut]

FIFY

We used to blame her Son with his dodgy TV/HiFi/Games console set up mackled together in his room but he was innocent.

They did manage to blow the main supply fuse once though, I was cooking dinner, he decided to have a shower then his girlfriend decided to Iron some clothes......................80 Amp fuse couldnae take it Captain.