Have a major problem

[james stas]

Hi guys, i'm not an electrician ,I'm a builder.

a month ago we had an electrician in first fixing, after he left some capping fell off and i put it back on with a nail. turns out i nicked the cable but it wasnt live until yesterday when he second fixed the outside light and powered on and left. I wasnt on site but later the customers got a shock from the wall several feet from the cable, the whole wall was live , because it was damp from the plastering i had done (like 3 weeks ago) and i nicked the cable. so its all my fault i am told.

Should this not have been picked up on the insulation resistance test?
And why did the electrics not trip? i mean if i put the nail into the cable today would it trip or would the whole wall be live? i got a severe telling off for putting customers lives at risk but builders sometimes damage hidden cables and it always trips and never in my life have i heard of a whole wall being live like this was.

Please post honest opinions. i need to know if its my fault.

thanks
James

 

[Toneyz]

Sorry but I can not see how this can be economical it will increase the job cost. Plastic capping instead of metal if the same thing happened the nail will still make the damp wall live.

 

[littlespark]

Devil's advocate:- is it 100% certain it was this nailed cable that caused the shock? Is there other circuits coming down the same wall to sockets for example? Maybe they are nailed also?
If OP works for his family, I hope they back him up and not point the finger solely at him

 

[Guitarist]

why not use the correct clips?
Tower Oval Conduit Clips 16mm White Pack of 5 - https://www.screwfix.com/p/tower-oval-conduit-clips-16mm-white-pack-of-5/72359

I have done, and do on occasions, but I find it's easier to keep the chase as shallow as possible with the washer method.

 

[Deleted member 26818]

Don’t like the clips for oval conduit, take up too much room.

 

[Sparkie30]

Stopped using oval,capping years ago. Chase 30-40mm deep and always carry a bag of bonding.

Never a problem with builder or plasters.

 

[EbolaSideRoom]

he said they would get a 6amp shock and it could kill them because it was over so many milliamps and because it was a floating earth rcb wouldn't operate. i'm starting to get ****ed off with this guy now

I'm not surprised.
Rule #1 of all electrical work - do not allow people to receive electric shocks!!
Regardless of the circumstances if a client of mine or anyone associated with them (or the job) had received an electric shock I'd be mortified, never mind who could be said to be at fault. Pointing the finger elsewhere just reeks of guilt, IMO. I'd look for a second opinion on the job, from someone suitably qualified and somewhat independent from the installer.
Also, and I'm not sure if this question has been answered elsewhere in his thread so please forgive me for asking again, was the errant capping plastic, or metal?

 

[Wilko]

... please forgive me for asking again, was the errant capping plastic, or metal?

My assumption is metal, in that a single nail "made the capping live".

 

[Deleted member 9648]

My assumption is metal, in that a single nail "made the capping live".

That was my assumption as well.
Many issues spring to mind with metal capping, not least that minor damage and a live nail head a couple of mm across will be amplified into a live strip of steel perhaps a couple of metres long. But also it's razor sharp edges may cut through insulation. I've seen this happen when it's installed, but also post install when cables are moved by other trades during building works.
I have used round plastic conduit for many years, only considering plastic capping for budget jobs.

 

[123]

Round plastic conduit is pretty much what everyone uses this side of the pond. Don't think wholesalers even stock capping

 

[telectrix]

only problem with the round conduit is that you need to chase into the brick. oval, on the other hand is generally only plaster depth.

 

[EbolaSideRoom]

My assumption is metal, in that a single nail "made the capping live".

Thanks - missed that in OP.

 

[GlenTavener]

my nail was making the capping live i am told and there was no imbalance between neutral and live because it was going back to the substation.,,....

The wall became live only as far as the dampness spread, consequently it is very unlikely that an IR test would reveal the problem, unfortunately the customer completed the circuit on contact with the wall as they bridged to some other earthed area. Such things happen and I have experienced it a few times. As someone has pierced his cables it is hardly the electricians fault he wasn't even there. In my case it was similar to this the builder just nailed in the wrong place even without moving the capping, just a simple error, we didn't make a fuss about it when it happened on our work, though fortunately our trips operated. Human error occurs, tiredness, trying to complete as quickly as possible many things, builders, like the rest of us don't make mistakes on purpose but we are all human. How would it have gone down if he had insisted the electrician be called back to fit it properly? I was always grateful for the help I got from builders making our job easier.

 

[Sparkingmad]

At least with round and oval provided it sized right you have a chance of rewiring it at some stage. Capping your generally screwed like that pre-wired flat conduit which never took off thank goodness.