Main RCD Tripping

[mt29]

Afternoon, have just moved into a new house about 3 weeks ago and since then the main RDC has been tripping 3 or 4 times a day, so i am losing all my power.
I was pretty sure it was the shower as, when i switched the shower isolator on it would trip, often but not always. So i turned the shower off at the breaker but it still tripped.
I have unplugged everything in the house but still it trips.
Could it be a wiring problem rather than an appliance? and should it not solve it by turning off the breaker?
I am going to have to call an elextrician but would like advice in the mean time and to try and save some money by identifying the fault myself.

Thanks

 

[wingcoax]

If it still trips with everything uplugged then it can't be the appliances. Wait for the sparkie, he will have the kit to test the RCD and wiring.

 

[1john]

definatly pulled the plugs out of the sockets for everything, not just switched the socket off, did you disconnect the boiler too, there should be a 3Amp switched fused spur that will turn that off, dont forget about any appliances under the kitchen worktop, like the washing machine, tumble drier, dish washer and all that....

 

[ColJack]

turning off the breaker will not stop a N-E fault tripping the RCD as the neutral doesn't go through the breaker.
when switched off at the switch, does it not trip at all?
if so then it's a fault between the CU and the shower switch..

lets start narrowing it down..

do you have any outside lights?
electric water heating? ( ie immersion heater )
outdoor sockets?
any other outside electrics ( including sheds etc? )

 

[mt29]

Thanks all for your replies.

Firstly the RCD still trips when the shower switch is turned off.
I have no outside electrics at all, no shed, external sockets or lights.
I have no immersion and have taken the fuse out of the boiler as thought this may have been the source originally.

I still think the shower the problem. I have an electrician coming round tomorrow now and he said he is going to test insulation resisitance? He also mentioned changing the main RCD for a Main Switch and installing RCBO's?? for the shower, ring main and kithen?? Didn't give me a price for this but sounds expensive?

Thanks

 

[mikhailfaradayski]

he should definately check for ins. resistance. The outcome of this will often reveal the problem.

Changing from RCD to RCBO may be prudent, but might not be necessary, can't say without further info.

If you post what the spark says/finds/recommends, possibly along with a photo of your fuseboard, others here could offer their opinions