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

 

[james stas]

westward,the sparks not been blamed for anything. pls re-read my first post. i'm here on a humble fact finding mission not to insult electricians. i have alrdy been told its my fault totally infrount of customers and collegues and i apologised and i was told repeatedly how bad i am.

 

[jackhammerJIM]

he says its going back to the substation and bypassing the rcd

So the rcd sees an imbalance and operates ...

 

[jackhammerJIM]

Unless it had an underlying N-E fault

 

[james stas]

apparantly not because it wasnt going to an earth it was going back to the substation iamtold and it would never trip?

 

[westward10]

westward,the sparks not been blamed for anything. pls re-read my first post. i'm here on a humble fact finding mission not to insult electricians. i have alrdy been told its my fault totally infrount of customers and collegues and i apologised and i was told repeatedly how bad i am.

The root cause of this was the capping not staying in place, had it been fixed correctly you would not be in this situation. Guarantee it you had contacted him to say it fell off he would have said just nail it back on.

 

[jackhammerJIM]

apparantly not because it wasnt going to an earth it was going back to the substation iamtold and it would never trip?

And how is it getting back to the substation

 

[Ian1981]

So does the nailed cable go into a metal back box on the wall to say an outlet/switch?

 

[Deleted member 9648]

I feel for you James. As the others have said there is a possibility that correct testing may not have highlighted an issue. But IMO a damp wall and damaged insulation on a buried cable would result in a poor IR reading which would flag up to an electrician not to energise.
I think it would be reasonable of you to put your hands up to an error in damaging the cable, but I also think it would be reasonable to argue that an IR test by the electrician should have flagged the problem before the cable was energised.

 

[KEV 1 N]

this is all with a brand new board. so it is possible to fit a light, test, leave and the whole wall is live?

I did the same thing when I fitted my kitchen last year fixing wall units, as soon as I'd drilled the hole I knew it was close to the cable for the under cupboard lights. So I tested the cable, no Insulation resistance faults and live, neutral and earth had continuity (unbroken), so I thought I must have missed it. When it came to grouting the tiles (at night with the counter lights on, I was getting a shock when applying grout and resting my other hand on electric cooker (earthed). Took the wall unit off, hacked the plaster away, there it was (as you had done) screw nicked live cable making capping live, only noticed when wall was damp! I too was getting around 100volts from wall to earth.

 

[The Ghost]

Why the hell didn't the plasterer get a shock then???

 

[westward10]

Why the hell didn't the plasterer get a shock then???

He/she may not have created a suitable path.

 

[KEV 1 N]

Why the hell didn't the plasterer get a shock then???

He/she may not have created a suitable path.

Maybe the outside light wasn't switched on when the wall was plastered

 

[westward10]

Tell him that you need to contact his scheme provider for some kind of resolution telling them the circumstances and that circuits were made live while the plaster was still damp.

 

[Octopus]

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.,,....

Best you tell the person that told you that, that its b o l l o c k s

 

[The Ghost]

suitable path

Then the OP who did the plastering is one lucky person with a metal trowel and water/wet things everywhere. Yes maybe the light was not on, but is that the outside light? I would have thought that a nail through the cable and the bare earth would have showed some kind of fault at that distance with an IR test between L-E not max ohms? I mean only one cable thickness away? Maybe he did not do switching both ways during IR?
Anyway if he changed the CU he should have completed all testing before commissioning the CU and handed over the cert to the person ordering the work, certainly within 30 days. Was that you who ordered the work @james stas?