The RCD in my consumer unit has started tripping. I tried isolating it by leaving individual circuits off but have got to the stage where it trips when every circuit is off and I just leave 1 on. It trips when i have just the cooker circuit on and when i just have the shower circuit on (and may well with just other circuits on - haven't tested beyond this).

Am I right in thinking it can't be a load problem (shouldn't be as it was fine previously with no significant changes) as indivual circuits aren't tripping - just the RCD ?

Can the RCD / consumer unit be faulty ?

Have also just found rats in the same void as consumer unit - can they do anything which may cause the above ?

Thanks.

Snapey, December 2008

What make of DB (fuse board) do you have.
Can you please give me the rcd or rccb details

paul, December 2008

Get an Electrician beofre you burn your house down.

You should get it professionally tested rather than use these websites.

If you want it done before Xmas and live in the Midlands call 07747 571292.

Paul, December 2008

Thanks Kenny - will try this.

Does this scenario fit for intermittent faults ? Ie the RCD only appears to trip when under a certain amount of load - somewhere around 6+ KW. (although for a week or so it tripped at between 5 and 6 AM when nothing apart from fridge / freezer and standby devices etc are on).

Thanks

Snapey, December 2008

Snapey
I'd be surprised if at the moment the two are not connected.

Kenny F, December 2008

Thanks Kenny - will try this.

Does this scenario fit for intermittent faults ? Ie the RCD only appears to trip when under a certain amount of load - somewhere around 6+ KW. (although for a week or so it tripped at between 5 and 6 AM when nothing apart from fridge / freezer and standby devices etc are on).

Thanks

Snapey, December 2008

Snapey
The RCD covers you for leakage to earth I.E. it "measures" the current in the live wire and compares it with the current in the neutral and if theres a difference of more than the set limit it trips the circuit.
I think your wee visitors have been munching your cables and have left you with a live wire touching the "earth" or an earthed metal part. this is a risky situation and the system shuts down. the RCD can mess about but its really, really rare and I would not be inclined to believe thats the issue. check out the cavity for chewed cables, look for dead rats you may have got a little payback before the critter fused your cables.
It may be possible to check if there is an earth fault if you have a meter.
With the mains power off (and tested please) and all sockets cookers and shower switches off disconnect the live wire coming out of the RCD to the fuseboard also disconnect the main earth wire and check across these. there should be no circuit in the ohms scale. If there is try tripping fuses until the fault goes away, maybe this will reduce the search area. if you cant test for this or find the chewed cable you may need to ask a sparky to come in. make sure yoou make a good job of reconnecting the earth wire as its the important one.

Kenny F, December 2008