# Safe way to determine if a wire is live?



## Jim Port (Sep 21, 2007)

Although they have limitations, this would be a good spot to use a non-contact voltage detector. Test on a known live circuit.


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## frenchelectrican (Apr 12, 2006)

I agree with Jim Port with the non concat voltage tester however when you check the conductor to see if that is alive or complety dead just make sure you don't touch the ceiling grid when you do this somecase it will be bonded one way or other if that complety dead then back track where that goes and if complety cut off on both end then you know it is non useable cable.

Merci.
Marc


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## jlhaslip (Dec 31, 2009)

cut the last inch with a pair of sidecutters. watch for sparks and/or the breaker tripping.

:whistling2:

Just kidding, of course...

:laughing:

[edit]
:jester: smilies and comment added to indicate this was posted in jest :jester:
[/edit]


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## secutanudu (Mar 15, 2009)

jlhaslip said:


> cut the last inch with a pair of sidecutters. watch for sparks and/or the breaker tripping.


I don't agree with this at all....get the non-contact voltage tester:

http://www.lowes.com/pd_18400-12704...currentURL=/pl__0__s?Ntt=non+contact+voltahge


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## gregzoll (Dec 25, 2006)

secutanudu said:


> I don't agree with this at all....get the non-contact voltage tester:
> 
> http://www.lowes.com/pd_18400-12704...currentURL=/pl__0__s?Ntt=non+contact+voltahge


I do believe it was meant to be a joke. I personally like taking the wire to my tongue and seeing if there is any voltage going through the line.


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## secutanudu (Mar 15, 2009)

I figured it was a joke...but those are the type that could get someone hurt if they don't realize. Not everyone on the forums knows much about this stuff, especially the new people!


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## gregzoll (Dec 25, 2006)

secutanudu said:


> I figured it was a joke...but those are the type that could get someone hurt if they don't realize. Not everyone on the forums knows much about this stuff, especially the new people!


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## secutanudu (Mar 15, 2009)

Yes, I realize the disclaimer is there. Still, I see no reason to joke with someone about cutting a live wire when they may not perceive it as a joke.


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## Fortitude (Aug 15, 2010)

Thanks for the info about the non-contact voltage detector. I'd never heard of that before.

I did recognize the joke answers.


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## gregzoll (Dec 25, 2006)

secutanudu said:


> Yes, I realize the disclaimer is there. Still, I see no reason to joke with someone about cutting a live wire when they may not perceive it as a joke.


If you can not recognize when a person is joking, then you are taking life way too serious. Yes, there are some things more dangerous in life than others, but when asking questions in a DIY Forum, you pretty much know that you have concerns.


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## secutanudu (Mar 15, 2009)

gregzoll said:


> If you can not recognize when a person is joking, then you are taking life way too serious. Yes, there are some things more dangerous in life than others, but when asking questions in a DIY Forum, you pretty much know that you have concerns.


I am all for joking...but do you know how new at electrical work some members are here?


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## Red Squirrel (Jun 29, 2009)

Another option is a volt meter, just touch the ends if they are easy to get to. The wire itself is safe to touch and handle, you just don't want to touch the end. Now if the ends are very close together there's a possibility of a short if you play with it too much, so if you need to move it around to get to, may want to shut the main, then turn it back on to test. 

If it's live then turn a breaker off one at a time turning the last one back on, until you find the one that controls it.


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## Bigplanz (Apr 10, 2009)

I was tracing a gas line in my basement last year and came across an old piece of BX, just cut off. I thought, "I wonder if this is hot?" I put a pen tester on it and it beeped like a mother. Great, hot cable just cut off and left up in the floor joist, laying on top of HVAC ductwork. I think it was an old circuit that went up to the kitchen which was abandoned when somebody remodeled the kitchen years ago. I carefully stripped and capped the wires and put the whole thing in 4 square electrical box. I have tapped into it for some basement lights and sockets, so I guess I was fortunate to find it. However, ASSUME NOTHING when you are in an old house. You will find some crazy stuff, like, oh, a hot cable cut off and laying on metal ductwork.


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## Kirky (Oct 2, 2010)

Heres something, if you dont have a non touch tester, try this put a regular flouresent bulb upto the romex (not cfl) dont touch the metal ends of bulb to the end of the romex wire. The bulb will glow ever so lightly in a darken room, because the emf in the wire will excite the photons in the gas in the tube.


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## Red Squirrel (Jun 29, 2009)

Kirky said:


> Heres something, if you dont have a non touch tester, try this put a regular flouresent bulb upto the romex (not cfl) dont touch the metal ends of bulb to the end of the romex wire. The bulb will glow ever so lightly in a darken room, because the emf in the wire will excite the photons in the gas in the tube.


Interesting, I did not know this. Makes sense though, I did discover as a kid that static electricity does make it glow, too. Move a plastic bag near one in the dark, it's pretty fun.


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