Wall socket circui tripping off seemingly randomly.

[Rjrose]

I'm at my wits end, so here goes...

The wall socket circuit in my home keeps tripping off. It occurs seemingly randomly - except 9 times out of 10 that it is after 6pm - and is always preceded by a flicker in the ceiling lights.

We've had the circuit breaker box and all the wall sockets tested by an electrician but he was unable to locate a cause, we've checked for obvious stuff like damp ourselves.

Does the fault have to be on the wall socket circuit thats tripping? We have 1 ceiling light socket that may be water damaged from a long ago leak and which trips the ceiling light circuit when a bulb goes, is it possible for something like that to trip another touchier circuit?

The main problem is the lack of predictability... people have suggested we are overloading the wall socket circuit (but it has worked fine with all 3 of our PC's on and tripped off with 1 or none on and the others unplugged), or that its an appliance shorting it? I would have thought a faulty appliance would be more predictable, until this weekend it had been a month since the last trip.

I'm at a loss and in no way an electrician or DIYer, any advice at all is greatly appreciated!

Thank you.

 

[Click-Sure]

What time does your central heating come on? Often the central heating controls, pump, valves and boiler come off the same circuit as your sockets, there 'should' be a switch with a little fuse holder next to it, try turning this off before it normally happens and see what occours.

 

[skenk]

What is it that is 'tripping off'?

I presume you mean a MCB (mini circuit breaker) or RCD (looks similar but has a test button on it) at the Consumer Unit (fuseboard, 'circuit breaker box').

 

[flameport]

Presumably the device that trips is an RCD (with a test button on it)?

except 9 times out of 10 that it is after 6pm - and is always preceded by a flicker in the ceiling lights.

Lights flickering indicates a heavy load being switched on somewhere. This could well be outside of your property.

Do any of your neighbours have welding equipment?

 

[Rjrose]

Sorry, mini circuit breaker MCB I think. The turn it off before wiring a socket one

Central heating currently comes on about 8am to 11am and then 4pm to 10pm, it hasn't coincided with the tripping - a fair few trips have after 11-12pm and we've only experienced 1 (out of about a dozen) during daylight hours.

Neither of our neighbours has any heavy equipment to my knowledge, wielding or otherwise.

A note, this has been occuring since Summer 2009 and personally I am wondering if it is connected to the new Kitchen we had fitted earlier in the year, we had a few wall sockets added and an oven.

 

[Click-Sure]

Any certificates for the work in the kitchen?

 

[Rjrose]

Yes.

It was that company we called back to check the wall sockets, etc as it is all under guarantee.

 

[flameport]

If the device tripping is an MCB, the cause is probably an intermittent fault on the circuit. The lights flicker because when the fault occurs, a large current flows, causing the voltage on other circuits to drop.

The 6pm thing must be related to some activity which happens around that time. This doesn't have to be anything related to electrical equipment - for example, if the fault was a damaged cable under a floorboard, the trip might be caused by someone just walking over that section of floor. Or perhaps someone uses the shower/bath around 5.00pm, water leaks from it and enough builds up to trip the circuit at 6pm?

 

[skenk]

Just to confirm, since it started happening you have had the installation fully tested for continuity & insulation resistance, yes? (results would be shown on a test results sheet accompanying certificate)

 

[Rjrose]

My mistake, we have no certificates from the testing done, just billed for it.

We have tried switching off the shower/bathroom circuit MCB in case of damp causing the trips (we recently had to replace a pipe, though it is nowhere close to wiring), they happened anyway.

I am very hazy on whether a fault on a seperate circuit could cause a trip on the wall socket one?

 

[ban-all-sheds]

My mistake, we have no certificates from the testing done, just billed for it.

That's wrong.

The work you had done was notifiable.

Do you not even have a certificate from the people who did it, or from the council, to say that it complied with the regulations?

If not then you should get that resolved, at the expense of the people who did the work, not leave it until years down the line when a buyer's solicitor starts asking you for the documentation....

 

[Rjrose]

We have the certificates for the actual kitchen wiring work. Just not the tests we had performed afterwards when the tripping began.

 

[ban-all-sheds]

Ah - sorry - misunderstood.

 

[Rjrose]

Just info on kitchen installation, in case anything is useful:

Details of the installation:

Cooker circuit
2x Socket circuits

Comments on existing installation:

16th edition consum(illegible)
No bonding to Oil. No RCO protection to garage sockets.
Water bond not vissable(sp?).

 

[ColJack]

ok lets get the basics out of the way..

do you have an immersion heater?

is it on a timer?
is it perhaps wired into the socket circuit?

do you have under floor/tile heating in the bathroom etc?

you mention oil.. does the tank have trace heating to keep the oil at a useable temperature?