RCP keeps tripping

[Fraser11]

My RCP keeps tripping but only when the sockets switch is on however the socket switch itself doesn’t trip. Have unplugged every socket, even took out the fuses from all the fuse spurs. Any suggestions?

 

[ProDave]

You have an earth leakage fault on the socket circuit. That will trip the RCD because that only needs 30mA of leakage to trip it.  It won't trip that circuits MCB as that is for a different purpose, overload protection.

It could be any number of things, damp, a pinched cable or several other things.

Make absolutely SURE everything is unplugged. Don't forget things that may be hard wired in like a cooker hood fed from an FCU. Otherwise this is unlikely to be a DIY fix as it is unlikely you will have an insulation tester.

 

[Murdoch]

Have you done any DIY lately?

Got any water leaks?

Got any rodents in your house?

This is almost certainly a neutral - earth fault, which without proper test kit and competence you'll struggle to locate and fix this

Sorry if this isn't what you want to hear .........

and its a RCD

 

[ProDave]

I would say a L-E leakage fault as it only trips the RCD when the socket circuit is turned on. But if it's damp or a damaged cable there is probably leakage N-E as well.

 

[Ardet R]

If you are absolutely certain that you have disconnected all loads that may be connected to the socket circuit, including odd ones like fused connection units for  boilers/heating, conservatory and outside lights and the like then you have a problem with the wiring of the circuit itself.

This is not the most likely situation as cables in walls are generally undisturbed (unless the walls are damaged or wet) and so nothing much changes there.  However it does happen and in that case it would be necessary to trace the fault within the circuit, unfortunately unless you are fully versed in how the circuit is designed then it can be a very hard and possibly very dangerous to be able to define where along the circuit the fault is located.

If the RCD trips and will not reset when the socket circuit is on then this is likely to be a "hard" fault i.e. the fault is a direct contact permanent fault and finding it should be relatively straightforward for a competent electrician.  However if the RCD can be reset then this is much harder to determine as it is a transient fault that may not be present when testing is carried out..