Intermittent RCD Trip-out

[mchu6am4]

Hi - here's my problem copied from another forum but I'm hoping for a bit of expert help please:

Original post - April 10:

Hi,

My RCD has tripped out for the 2nd time in a month. The cause seems to be the sockets ring main as if I switch off the breaker for the ring main the RCD is fine.

The first time it tripped out, I unplugged everything from every socket (except my new Bosch washing machine which I couldn't get to as I have a broken wrist and could not pull it out from under the worktop to isolate) and tried switching on the ring main breaker but it kept tripping out the RCD.

I rang an electrician (on Good Friday) and he said he might be able to come out later to have a look but didn't. Instead, he rang me after a few hours and told me to switch on one breaker at a time and see if the RCD trips out and miraculously it didn't!!!! The ring main seemed fine although nothing was connected except the washing machine. I then tried to plug in one thing at a time to see if anything trips out the RCD but it didn't!

The same thing happened again this morning and I repeated the same process as above (with the washing machine still connected), however the RCD kept tripping out due to the same ring main breaker! I tried about an hour later and same result! Went to work p*ssed off and came back after 8 hours and switched the breaker for ring main and it DIDN'T trip!!!!! just like last time!

So it seems as soon as it trips out it takes a few good hours and the fault clears - I don't understand. BTW, its an MK consumer unit with 80A RCD.

ANY IDEAS OUT THERE PLEASE?

thanks, Ash



UPDATE - August 10


Below is my latest update:-

The tripout continues to happen during or following use of electric shower. I have disconnected EVERYTHING from ALL the sockets including the washing machine and the fault still persists!

So I disconnected the shower COMPLETELY from its circuit breaker including the earth and the neutral terminals and tried to reset sockets ring main breaker and same result....the RCD trips!!!

I've also tried the following;
Before taking a shower...I switch off the sockets ring main breaker...take the shower (never trips while using the shower with the ring main off) and switch back on the sockets breaker and the results are as follows:

Sometimes it'll trip out the RCD and sometimes its OK.....but what I DON'T get is where the link???...the shower seems to upset the sockets ring main while it keeps working fine!!!!!!!

PLEASE HELP...as its driving me mad!!!!!

Thanks, Ash

 

[Izzy's Dad]

Sounds like you have water leaking from your shower tray mate.

 

[poheZ]

The easiest thing to do is to get an electrcian to test your circuits. Any decent sprky will know what values to look for and what may be causing the problem.

What you are doing is helpful as it will almost certainly aid the electrician in finding the cause of the fault.