Random earth leakage problem

[Dave A]

All circuits on E.L.U. must have the neutrals going through the E.L.U. as well.

Also the neutrals for all circuits not on the ELU must also not be on the ELU neutral bar.

Crossed neutrals don't constitute my definition of nuisance tripping though. That's a permanent wiring fault that should be easy to identify.

[BillH]

Based on what I have learnt through this forum, I am going to do the following to reduce the "capacitance" problem:
Appoint a registered electrician to:

1. Get the garage ELU wired correctly;
2. Take my office's dedicated plug circuit off the ELU completely - the plugs in the office are all in cupboards and can be "red plugged".
3. Split the remaining circuits on the DB into 2 ELUs (there is space for another one).

Agreed??

[AndyD]

Sounds like a good plan to alleviate the inconvenience factor. The plan isn't likely to actually remedy the core problem although if the contractor has his eyes wide open he may come across the problem during the work.

@ Dave, your right, the definition of nuisance tripping doesn't include wiring faults. Nuisance tripping is when a protective device trips for no valid electrical reason. I'm also guilty of using the phrase out of context and most customers assume that nuisance tripping means any tripping fault that'sa nuisance to them.

[Sparks]

So many possibillities, and more than enough knowledge on the forum, but without actually being on site it is impossible to trace the cause.

[bergie]

bill,i can help you out. the only problem is i am travelling from blouberg.it would add an hour each way onto every trip,making it expensive.pm me if you need me

[murdock]

if the neutrals are conected on the wrong neutral bar...as soon as you apply a load the earth leakage will trip (should trip)

[Adam Mashinini]

cbi, let's see, their e/l, i dont use, their switchgear, i dont use, their anything they make or touch, i dont use.

do yourself a favour, buy a lear e/l at around 210 rand, replace the e/l and see if the problem still exist. if so, then from there on it is a process of elimination. eliminate circuit by circuit (that means live AND neutrals) until you get the SOB. sometimes it is more than 1 circuit, but u will get there, should not take u more than 1 to 5 hours.

or, get an expierenced eleccie to do it for u, should not cost you more than 12 grand. :-)

[AndyD]

I've haven't had problems with CBI equipment as such, it's okay, it's just overpriced. I can buy Merlin Gerin cheaper than CBI so it's a no brainer.
I would ramp test the RCD first and check the disconnect times before replacing. RCD's that nuisance trip when there's no fault are very rare, 99.9% of the time if an RCD trips there's a fault that's causing it.

Did you get the problem sorted out by the way Bill?

[bergie]

i went through there and took the garage db off the main earth leakage. i didnt even try looking for faults as there was about 15 circuits on 1 earth leakage and the accumalative earth faults must be very high. i recommended a new d.b. with up to 2 extra elr's. once that is done it will be very easy to find any faults. there might not actually be any fault.

[murdock]

been having a fair share of these random tripping issues...especially the weekend ones where people get a call to tell them that the alarm battery hasn run flat( i know you should have the alarm on e/l )i wasnt the fool who wired it like that...and others who arrive at work on monday morning and the office power has tripped...this has been happening for a couple of weeks now.

then i got an interesting call today...a customer complaing about a power surge at 1 am on saturday morning...which caused a problem with some electronic equipment...then while chatting about that issue another person indicated that the saturday night there was an outage in the area...starting to wonder if its not time to connect the fluke 435 to the db and monitor the power over the weekend...why i am concerned is the fact that everything is shut down for the weekend...yet it still trips...got me thinking.