Discuss Split load RCD woes in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

C

chronyx

The usual C.U. change problem.

All circuits working except one (Ostensibly a ring circuit, once upon a time. It 'end-to-end's at the board) which seems to have a neutral to earth fault.

I was methodical so I don't believe any neutral conductors were misplaced, but even putting the two neutral conductors concerned into the small pre-RCD neutral bar that the RCD tails go to, resulted in an RCD trip as soon as the circuit was loaded, although not from merely touching them on the bar as below.

There's no continuity between either of the Neutral conductors and the 2 split load neutral bars, yet touch one of them onto either neutral bar and the associated RCD will trip.

Did as much investigation as possible after C.U. change and changeover switch install for a small back up generator.

In my roundabout way I'm just wondering if anyone has seen this before or has any tips. The circuit has been modified over the years so I can't really vouch for its condition. Just thought it was worth asking the hive mind.

One other question - would removing the tails from the RCD neutral bars so that they are electrically separate, then checking for continuity help identify a misplaced neutral? I assume no continuity would be desired.

There's a PayPal drink on offer to anyone that gives a winning answer!

Cheers!
 
Last edited by a moderator:
Have you done a full dead circuit test while fully disconnecting the ring from the board or are your globally testing them, also was the main switch on when you found your N/E issue?
 
As time was short I ended up looking for likely areas where a cable could have been damaged and I.R testing, but not the whole circuit yet. Found one that was very tightly packed against a stud, but it tested out OK and my eureka moment was lost.

Good point about the main switch, I see where you're going with that. It was on.

A 10pm reply is appreciated too!
 
Last edited by a moderator:
Disconnect the circuit, test it in a logical manner, find the fault, fix the fault, test, fill in the certificate, job done.
It's as simple as that!

And it might be an idea to not waste your time touching conductors to different neutral bars to see what happens, it won't achieve much and makes you sound like your not a competent electrician.
 
I've had similar recently, and it took me hours to sort, I eventually fixed all 7 seperate issues. But Davesparks and Darkwwod are right, follow your dead testing fully and in the prescribed order and you will get there. You may find like me, that there are multiple faults and as you find and fix one, you start back at the begining at work your way through. There is little point in going for best guess when you already have the tools, be methodical and logical and you will prevail.
 
And a logical testing process will find it a damned sight faster and without making you look like you are just guessing at the fault in the eyes of the customer.

Top marks on being as condescending as ever david, If you split and then half and half a ring you will find the fault in no time, how are you going to find an open ring without dropping sockets? Speaking from experience it should only take 30-45mins to find with this technique. And as far as looking like your guessing, the customer knows nothing of the practices of an electrician so that comment is redundant.
 
Top marks on being as condescending as ever david, If you split and then half and half a ring you will find the fault in no time, how are you going to find an open ring without dropping sockets? Speaking from experience it should only take 30-45mins to find with this technique. And as far as looking like your guessing, the customer knows nothing of the practices of an electrician so that comment is redundant.

Simple, short two conductors together at the CU, then test resistance at each socket (without removing it) and the readings will gradually increase towards the break and will be highest at the last socket each side of the break. So then you should only need to remove one or two sockets closest to the break.
 
or: try a Zs at all the sockets and write down the readings, if you get 2 close together and the readings are quite different, start looking there!
 
Top marks on being as condescending as ever david, If you split and then half and half a ring you will find the fault in no time, how are you going to find an open ring without dropping sockets? Speaking from experience it should only take 30-45mins to find with this technique. And as far as looking like your guessing, the customer knows nothing of the practices of an electrician so that comment is redundant.

To be fair Dave Helps a lot of members out with his knowledge and he knows his onions, yes his replies can sometimes appear a bit sharp but he always comes up with the goods.
If anyone takes a look at the top thanked,liked,poster, thread starters section you can clearly see that he is actually the top poster and also most thanked which for me is the important one because it proves he helps out a lot on the forum.
Just saying :wink_smile:
 

Reply to Split load RCD woes in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock