RCD Tripping

[mjw1953]

RCD is tripping taking out all sockets and house alarm. Resetting the RCD brings back all circuits except the kitchen sockets. The MCB is in the 'on' position for the kitchen sockets and the only way to bring these sockets online is to switch off the circuit via the MCB and then switch back on.

Does this mean that the problem that causes the RCD is on the kitchen circuit?
Could the RCD or the MCB be faulty?

The CU is split with all lighting unprotected and all sockets (including those supplying freezer) on the protected side.

 

[ericmark]

From your account the kitchen MCB does seem suspect. But to detect an earth leakage problem one needs expensive meters and it would not really be cost effective to try to DIY fault finding of this type.
Replacing the RCD and MCB's for RCBO's and isolator may pin point the problem and cause less disruption when the fault occurs.
Eric

 

[ban-all-sheds]

From your account the kitchen MCB does seem suspect.

Or there's a P-E fault which is taking out the MCB and the RCD at the same time?

mjw - if you are confident and competent to work inside the CU you could try swapping the kitchen circuit with another socket one and seeing if the same or different MCB trips.

If it's the same it looks like an MCB fault. If different it looks like a genuine fault in the kitchen - you need to get an electrician in pronto.

I take it that the trips don't coincide with anything obviously appliance-related?

 

[FDJ]

RCD is tripping taking out all sockets and house alarm. Resetting the RCD brings back all circuits except the kitchen sockets. The MCB is in the 'on' position for the kitchen sockets and the only way to bring these sockets online is to switch off the circuit via the MCB and then switch back on.

Does this mean that the problem that causes the RCD is on the kitchen circuit?
Could the RCD or the MCB be faulty?

The CU is split with all lighting unprotected and all sockets (including those supplying freezer) on the protected side.

Some MCB's when tripped leave the operating lever in the ON position and, like yours, require an OFF/ON to reset.
I would look at the loads connected to the kitchen circuit. Anything with a heating element, I would suspect first.
(Dishwasher, Washing machine, Oven, grill, kettle)
You need to pin the trip down to a particular appliance.

Frank

 

[mjw1953]

Cannot say for sure that the fault is appliance related. The only two thing that are on all the time on this circuit is a fridge and a freezer (both built in of course ) which I will turn off and start tracking the problem. I'm not confident enough to swap mcb's so it looks like a local sparks has a little job to do.

Thanks for all the advice.