Earth Leakage problem

[Marvo]

^^Yeah deffo not a voltage operated device. The set up above is pretty much standard for large domestic and small commercial, we don't usually use pre-assembled CU's and I'm surprised there's even busbar, usually the MCB's etc just have multiple wire links across the tops of them.

Not sure why it's a 3-phase supply, domestic is usually single phase 60A but wit three geysers it's possibly commercial. The fixed loads such as geyser (immersion heater) and also the outbuilding should be fed by d/pole SP+N MCB's so the DB is not compliant.

JSpark, the board is a bit rough even by our standards but par for the course. Refer to the previous posts, identify the L+N of all the circuits on the RCD and do the tests for insulation and crossover with other circuits. Just be methodical, treat as dangerous until you figure out why the earth leakage is tripping with the main breaker off.

 

[J.Spark]

I forgot to mention that there is a main switch on the energy dispenser unit (as per pic) which serves as the main switch. This one cuts off the neutral as well.

 

[J.Spark]

Yes the board is very shoddy. This DB was wired by some magician 5years ago. Though 3phase set ups are quite common here in domestic installations depending on what the client requires or municipality requires etc etc. You even get some bachelor flats here that have a 3phase incoming supply.....so yes some of the 3phase set ups here are overkill.

 

[J.Spark]

Geez guys....this problem is not cool! Went through the entire DB....neutrals are all where they are supposed to be....lives where they are supposed to be but still when switching off the mains at the energy dispenser which cuts off neutral as well the ELCB still trips. Sometimes it stays on for as long as 5mins and sometimes within a few seconds it trips out. I feel like back pedalling out of here. Driving me insane!

 

[HandySparks]

...but still when switching off the mains at the energy dispenser which cuts off neutral as well the ELCB still trips. Sometimes it stays on for as long as 5mins and sometimes within a few seconds it trips out.

With the supply isolated at the 'energy dispenser' (not a term we're familiar with over here), try measuring the voltages around the offending ELCB: L-N, L-E, N-E, on both supply and load side with the ELCB both closed and open. I'm finding it hard to understand an ELCB (or RCD) tripping without a supply of some sort.

 

[J.Spark]

Yes it's very hard to understand. I cannot for the life of me understand this. Haven't cone across a tripping issue like this in all my years of being in the trade. An energy dispenser (ED)/ pre-paid meter is the unit the municipality installs so that the consumer can buy their own units of electricity and punch it in which does away with the conventional billing system and the council (lazy buggers) reading of the meter every month.

 

[Marvo]

Don't give up, it sounds like it's actually getting interesting, I like interesting, it's refreshing to get involved in fault finding where things are seemingly unexplainable.

Just a thought and a long shot as well, when the power is isolated on t-pole MCB on the pre-paid ED try testing for DC voltages L-N, L-E & N-E in the DB as well as AC voltages.

 

[J.Spark]

OK will do....thanks. I will have to explain the enormous bill these clients are gonna get for a time consuming tripping problem lol! Will keep you updated