Earth leakage trips at night??

[AndyD]

I thought that might have been some kinda leading question or even an ambush Adrian

[mikilianis]

Start with taking the lighting circuits off the E.L.U. take note you must also take the lighting circuit neutrals off the neutral bar supplied through the E.L.U. Perhaps there is an ingress of moisture through condensation on the outside lighting,as I have mentioned before, the neutral conductor is a tricky one.

[Jongseun]

Friday night I’ve started disconnecting the neutrals per circuit breaker. I started with the lights, went on to the swimming pool breaker, so tonight I’ll disconnect the plugs. I work in the electrical field but on light current electricals, so I do have some experience in electricals, I want to rule out all the possibilities before I get an electrician out. I have a surge arrestor installed in my D/B, could that also give me problems?

[AndyD]

Surge arrestors could cause an RCD to trip but it's fairly unlikely. You can install the surge arrestor before the RCD if the RCD's not being used as the main means of isolation for the DB.

[Tinman]

Hi Just my pennys worth
The pool electrical housing and any outside lights, condesation causes the fault and dissapears during the day.
Just take note of the weather conditions when it trips.

[Jongseun]

I narrowed down the tripping problem. When I disconnect the neutral of the light circuit (Main bedroom, main bathroom, study & bedroom light), the tripping stops. I’ve inspected the light fittings and it all looks in proper working order, I replaced the main bathroom light fitting…….So I also think moisture or the cold weather could be the culprit here, but how will I fix something like this?

[murdock]

that could explain why it trips at night.

[Jongseun]

The funny thing is last week I did not have any trips, I did not disconnect anything.....and last week it was freezing here in Jhb! very strange, and very irritating!

[AndyD]

I admire your tenacity but if you haven't managed to pin the problem down by using elimination in the last three weeks then it might be time to call in the big guns (qualified electrician) or try your hand with a Mega tester if you're competent to know how to safely isolate and how to use one. Chances are the tripping is a cumulative issue where more than one or possibly even several IR faults are adding up to more than the 30mA tripping threshold.