Identifying live cables

[markthebuilder]

hi gents . I’m currently surveying a property prior to remodelling it... it was a department store and it’s been redeveloped at least once but no one has pulled out the old wiring,
I want to mark up any of the major 415 3 phase that is defiantly live ina simple way so we can focus on tracking and verifying potentially dead cable most of the stuff I’m talking about is between 1.5 inc and 3 inc sea. Will a volt pen do the trick or do I need something different. Obviously anything that seams dead needs tracing and proving before we do any work . I just want to be able to quickly show what’s live so we can protect them and get them shown ondrawings

 

[derek]

I think you need an electrician, a volt pen is no good especially if you are talking about ripping stuff out ready for a refurbishment.

 

[Charlie_]

Do you own a ‘volt pen’ ?
If so, isolate a circuit and then see if you can identify it amongst a bunch of live cables..

 

[TJ Anderson]

Try a "volt pen" on SWA, MICC or FP.......

 

[markthebuilder]

1) I will need a team of sparks befor I’m finishe 2) no I don’t, I have always proved cables at one end or the other or been able to isolate the whole supply. This building is prity vast so when I am sticking my head in places I don’t rally want to go back to and I see a big black cables 2 inch thick I would like a quick way of determining if it’s deep live then I can mark it on the plans. If a volt pen will do volt pen will do it then that will do.. any cables I don’t get a positive result for can get marked up as require further investigation.
However if there is something a bit more reliable than a volt pen I will get one,

 

[ipf]

1) If a volt pen will do volt pen will do it then that will do.. any cables I don’t get a positive result for can get marked up as require further investigation.
However if there is something a bit more reliable than a volt pen I will get one,

In your case the thing more reliable is someone qualified to test correctly and inform you.
It could be very dangerous going about things in the way you intend.

 

[TJ Anderson]

Volt pens are good as an indicator, but won't work through the sheath of many cables.

What cables is it? You mention 2" thick......SWA I'd imagine, a non contact volt stick won't pick that up.

 

[ipf]

Volt pens are good as an indicator, but won't work through the sheath of many cables.

What cables is it? You mention 2" thick......SWA I'd imagine, a non contact volt stick won't pick that up.

We're talking 400v, here TJ. 'Prity vast' sounds like it could be quite complicated to me ( a bleedin' department store), could be cables all over the place. What about sub boards, removing live fuses, etc. God knows what could be live and what might happen with attempted removal.

 

[Deleted member 105166]

Are you intent on keeping any of the old cabling or shall you be renewing all boards and cables? Do you need the existing cabling as a supply during construction works? These factors may influence how you tackle things and in what order. You’ll need to involve an electrician from early on regardless.

 

[derek]

You need an electrician with experience in commercial installs, there can be some really dodgy wiring where there has been countless alterations over the years and it can catch out those who don't carry out a thorough safe isolation procedure.

 

[TJ Anderson]

We're talking 400v, here TJ. 'Prity vast' sounds like it could be quite complicated to me ( a bleedin' department store), could be cables all over the place. What about sub boards, removing live fuses, etc. God knows what could be live and what might happen with attempted removal.

I know......Totally agree!! Shouldn't be relying on a volt stick for it. If he is getting a spark in anyway....why can't they do it....

 

[ipf]

I know......Totally agree!! Shouldn't be relying on a volt stick for it. If he is getting a spark in anyway....why can't they do it....

By the way, might be an old Woolworths ….did they used to sell volt sticks?

 

[Charlie_]

My new fluke t6 1000 arrived yesterday.
I’m going to start putting it through it paces tomorrow so will let you know but then that will only be useful for single cores...
What you are attempting to do is very much involved.. There is specialist equipment available to identify individual swa cables but need to be used by competent operatives..
I have regularly been asked to make building sites safe for demolition/refurbishment works.. my solution - isolate everything and set up temporary supplies..

 

[Andy78]

I want to mark up any of the major 415 3 phase that is defiantly live

If these cables are going to be defiantly live you're gonna need to make doubly sure those stubborn buggers are dead.

If a volt pen will do volt pen will do it then that will do..

No a volt pen will not do. You need someone who knows safe isolation procedure in accordance with HSE guidance and compliance with the EAWR. They need to be using approved equipment and have the knowledge to use it correctly. In short, an electrician.

Any blundering about with limited knowledge and volt pens could put people in serious danger, and those that have put them in danger exposed as incompetent and action taken against them.

 

[markthebuilder]

Thanks ty for the constructive response. TJ the cables are Mostly big .others .are f’ing .. IPF is correct though there are sub boards everywhere and his implication reasonable if incorrect . I came across an installation today that ,looked derelict but on closer inspection still had one apparently live main switch with a supply going somewhere So marked it on the plans as poss live needs further investigation ( I suspect it feeds a lift Moyer 4 stories up) I also found a cable that entered the building 30 m from where i would have expected it to I know that’s live because I can see the meter going round ...that’s going down as arrange dno to relocate meter. However some of these cables I don’t think we can easily trace back to source or termination to prove. So at this stage being Abel-to show a cable is live or possibly deadwill help me plan the works.