RCD PROTECTED KEEPS TRIPPING AT NIGHT.

[bigboyo0]

Good morning
I have had building work done.
I have extended my house and Elecrician has put a new consumer unit in the new part of the house and run a cable back to the old consumer unit.
Problem is the new consumer unit has started to trip out some times at night some times in the day?
How do I find where the fault is coming from if not there all the time and only trips out the main switch to the new consumer unit.

Thanks in advance

 

[ericmark]

Likely something on a timer or on a photocell. So outside lamp, freezer, washing machine, off peak heater etc.

 

[Taylortwocities]

If at the same times, could be heating system/boiler.
I'd get the electrician back and have him sort it. Any earth faults should have been identified when he tested the circuits.
He did test the circuits? Have you got the test certificate?

The fault will be something in or attached to the extension.

 

[Risteard]

Any earth faults should have been identified when he tested the circuits.

Slightly unfair on the Electrician. Testing merely supplements inspection and can't be assumed to be capable of finding every single fault (especially if intermittent) - that's why care needs to be taken during erection as well.

 

[Taylortwocities]

Yes, I know. I was trying to tease some information about testing from the OP.