Main electric circuit breaker trips off

GazH

Hi All,

I am hoping this is the right forum to post on, so here goes.

Our main circuit breaker has tripped a couple of time today. This is the main on one on the board, not one of the house circuits (lights, cooker etc).

Is it possible that this is down to a faulty appliance etc?

For some reason I would have thought that the particular circuit would go rather than just the main one but not sure how it works.

We are keeping an eye on it and trying to work out where the problem is coming from before we get an electrician out but thought I'd ask teh wise board member first.

Many thanks in advance

Gaz

macman

Yes it would normally trip the circuit that the faulty appliance or light is on. If the main switch is tripping it might be a fault in the CU itself that you would need a qualified electrician to look at.
What causes it to trip-can you isolate the cause?

ormus

probably a faulty main breaker.
the other breaker/s should trip first if any appliance/circuit is shorting out.

AdrianW2

By "main circuit breaker" I assume the OP means the RCD?

In which case it could be a fault/damp in/on any of the circuits, a faulty MCB or a faulty RCD.

Hopefully 27col, fluffpot or baldelectrician will be along soon!

GazH

Hi All,

Thanks for the replies so far.

Macman, no not been able to isolate the faulty appliance yet.

The circuit breaker is in the garage, so it could be damp?

Think we will just get an electrician out anyway to be on the safe side.

Thanks for the replies guys it is appreciated.

Gaz

macman

So it's not tripping when you switch something on-just randomly?
Probably a faulty RCD or MCB then. Easily fixed with a replacement.
If the garage is noticeably damp then it could be that, but plenty of CU's work fine there, unless there's a hole in the roof or something.

GazH

We've switched off an old fridge freezer in the garage this afternoon and it hasn't tripped since.

Gonna probably switch back on tomorrow to confirm it is this but it seems liek itmay have been the culprit.

Many thanks for all the replies.

Gaz

jonesjw

Best to go looking for earthing problems within the appliance if it is tripping the RCD (sorry for being so obvious).
I had this & it was water getting in the microwave turntable motor.

27col

It is extremely difficult to find an intermittent fault. If you cannot reproduce the fault at will then there is not much point in looking for it. If doing a particular action causes a fault then it is usually fairly easy to sort out. If your RCD tripping is random then it would probably make sense to replace the RCD. In the meantime keep looking for a faulty appliance. It sounds as if you are on the right track with the old fridge/freezer.

baldelectrician

It may be an appliance

Look for a pattern;
When does it trip (note what was plugged in - even if it is not in use)
Check extensions (cable may be crushed below bed)
Do you have any roof leaks?
It could be your kettle, or iron (is the kettle left plugged in?)

Firstly
Unplug everything (remove plug, don't just switch off), keep fridge / freezer in.

It is usally things (in order of ocurrance)
Iron
Kettle (one with base - usually soapy bubbles on base)
Washing machine / dishwasher
Water in outside light, does it trip around dusk?
Outdoor items (pond stuff etc)

hope this helps

GazH

Hi All,

Thanks very much for the replies.

It does look like it is either the Fridge Freezer or the extension cable that is running to it.

Was going to try and have a look at teh cable and if ti looked alright maybe switch teh fridge/freezer back on and see if it tripped.

Nothing has tripped off since we switched it off on monday so looking positive.

I think I was just more surprised by the fact that it was the main circuit breaker tripping and not one of sub (RCD?) ones. Usually these would trip off if we overload etc.

Thanks again for the replies, they are all invaluable. :T

Cheers

Gaz