Borrowed neutral discovered when changing CU and discussion on DIY CU change

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

When you've done can you come round and perform brain surgery on my wife? I know you're not a qualified brain surgeon, but as long as you do it safely and write down all the results on a bit of paper for piece of mind, it'll be fine.

But there isnt a brain surgeon forum is there??

 

[Clive P]

Re: Borrowed Neutral discovered after changing CU

Hi,

I probably shouldn' say this, but the poster is in Scotland and it doesn't have to be notified. There is nothing that he is doing that hundreds of others can do there, at least he is asking for advice.

Regards.

 

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

But there isnt a brain surgeon forum is there??

Nar ive googled it.. Deffo not.. Looks like that one trade that you can ask the professionals what to do..
Surely there should be a more vigorous sign up to this.... :ban:

 

[Dan the spark]

Re: Borrowed Neutral discovered after changing CU

Call me silly, but how could a screw head be live and not blow a fuse?? Surely you had earths at the fcu's??

 

[rsmck]

Re: Borrowed Neutral discovered after changing CU

When you've done can you come round and perform brain surgery on my wife? I know you're not a qualified brain surgeon, but as long as you do it safely and write down all the results on a bit of paper for piece of mind, it'll be fine.

No, unless you seriously dislike your wife, I have a feeling that would end quite badly - I have no medical experience nor any desire to learn. That makes it a bit of an unfair analogy...

 

[Dan the spark]

Re: Borrowed Neutral discovered after changing CU

The more I look at this, the more I think this is a wind up!!

 

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

No, unless you seriously dislike your wife, I have a feeling that would end quite badly - I have no medical experience nor any desire to learn. That makes it a bit of an unfair analogy...

Yeah but you have watched casualty haven't you, What training have you had at being a spark and what experience have you at testing ?

 

[rsmck]

Re: Borrowed Neutral discovered after changing CU

Call me silly, but how could a screw head be live and not blow a fuse?? Surely you had earths at the fcu's??

Good question - don't have a good answer for you. All I know is that when that circuit was energised it instantly tripped the RCD.

A bit of investigation narrowed it to only being when those FCUs were switched on, when removing the faceplate, the damaged live conductor was clearly visible. Disconnected at the other end, checked the cable, reterminated the connections (with a sensible length, rather cable being stuffed into all corners of the back box) reconnected and everything works ...

I would have expected it to blow a fuse too, unless of course the earth also wasn't properly terminated previously.

 

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

Call me silly, but how could a screw head be live and not blow a fuse?? Surely you had earths at the fcu's??

Rubber Screws.. Or :****:

 

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

Good question - don't have a good answer for you. All I know is that when that circuit was energised it instantly tripped the RCD.

A bit of investigation narrowed it to only being when those FCUs were switched on, when removing the faceplate, the damaged live conductor was clearly visible. Disconnected at the other end, checked the cable, reterminated the connections (with a sensible length, rather cable being stuffed into all corners of the back box) reconnected and everything works ...

I would have expected it to blow a fuse too, unless of course the earth also wasn't properly terminated previously.

Dead Tests... Errrrm lets start with IR (L-E) what was your reading?

 

[Dan the spark]

Re: Borrowed Neutral discovered after changing CU

Rcd would have picked up a damaged neutral, fuse would have picked up live to earth. Seriously mate, I wouldn't be sleeping in any house that u had changed the db let alone rewired........ Wind up!

 

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

- - - Updated - - -

Rcd would have picked up a damaged neutral, fuse would have picked up live to earth. Seriously mate, I wouldn't be sleeping in any house that u had changed the db let alone rewired........ Wind up!

Now I think that a little harsh.. They guy has said he knows what he is doing and how to test an install... However its took energising the install in order to realise there was a fault..

Or is the OP tester the 99p variety that comes from china in the form of a driver ?

I agree I think somebody could be extracting he urine here.....

 

[MDJ]

Re: Borrowed Neutral discovered after changing CU

I liked the fact he changed the DB but insisted he wouldn't rewire the house and the spark that will rewire it will use his DB lmao, umm okay If you say so.

 

[rsmck]

Re: Borrowed Neutral discovered after changing CU

Yeah but you have watched casualty haven't you, What training have you had at being a spark and what experience have you at testing ?

Since you ask - I worked in IT/Telecoms for a long time including data centre management, whilst I didn't wire these myself (obviously) I have a good understanding of the *use* of such electrical installation and the concepts associated with them - e.g. UPS systems, transfer switches, generators etc and monitoring the power usage of such installations. I was also responsible for regular testing of equipment.

Outside of this I work as a theatre lighting technician (In theatre this is often actually referred to as "an electrician" - bit of an unfortunate misnomer) and so again need to understand testing, safe wiring practices (many venues make up their own cables including 3 phase cables) and various other electrical things mainly concentrating on lighting.

In terms of formal training - none, just experience and never being afraid to ask if I'm unsure, and getting someone else to do it if I still don't fully understand the answer.

As far as testing, my current home is the first that I've carried out full IR/Zs testing etc following a full rewire (replacing a 1950s VIR installation)

Note - I do not consider myself an electrician - but am happy to undertake basic electrical work for family (fitting lights, new sockets etc) and adhere to all relevant regulations where practicable (obviously old installations won't comply with everything!) and more extensive ones (like rewiring) for my own home.

As an aside this has been discussed (at length) in previous posts

 

[bigbaddave]

Re: Borrowed Neutral discovered after changing CU

I dont understand if no other work was getting done and they are having professional electricians in to do the rest of the work in few months time why in there right mind they have let this kidda play around with it.. I agree with MDJ.. probs end up paying twice in my opinion..