Earth leakage trips at night??

[Jongseun]

The problem I have is that my earth leakage only trips at night.
This problem started about 2 weeks ago. So room by room I unplugged all appliances from the wall mounted sockets till I ended up unplugging everything in the house, still I had trips.
All my appliances are on during the day and I have no trips during the day. We’re heading into winter now, so I don’t know if the cold at night has any effect on this.
There’s not a specific time for these trips as it happens randomly during the night.
What are the signs of a faulty earth leakage unit?

[adrianh]

Or you may have moisture building up that causes a short.

[Justloadit]

Or an evening visitor chewing on your wires.

[AndyD]

Hi Jongseun, welcome to the forum.

If you scroll down toward the bottom of this page you should see 'similar threads' are listed (maybe not if you're using a mobile device). You can read this one particularly for some fresh ideas.

[maxwel]

Hello Everyone

I am new to the forum. I work for an electrical services business in Cape Town. The problem causing nuisance tripping is ingress of moisture in the fixed electrical installation. Get a competent electrician to work on it while fault is still active.

Maxwel

[Jongseun]

Where would one find moisture in the electricals? I don't have any sockets outside, just lights. It seems to be that the later I go to bed (not using allot of electricity) the later the E/L will trip...Could a faulty E/L unit also be the culprit here? I've read on here that CBI E/L units manufactured in 2006 where faulty. My place was build in 2006...
What are the symtoms of a faulty E/L unit?

[AndyD]

The likelyhood of the actual earth leakage breaker being faulty is pretty slim. You'll need to get an electrician with the right equipment around to ramp test it otherwise there's a good chance you replace it and the problem still persists. Similarly if you've visually checked everything and ruled out all the appliances in the house by unplugging them then you will also need an electrician with suitable equipment and experience to locate and repair the problem.

[adrianh]

What would be the suitable experience and equipment?

[AndyD]

A good understanding of general electrical safe practices, IR faults understanding and experience, knowing effective isolation of circuits, how to identify crossed and borrowed neutrals etc.

Equipment would be a good multi-range and multi voltage Mega tester, a high res low current clamp meter, an RCD ramp tester with test wave reversal and trip timer, earth impedence tester, a general multimeter and a triplicate carbonised invoice book.

[adrianh]

Ah....:-)

[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.