Help- I cut a live Romex wire
#1
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I'm embarrassed to admit it but I want to make sure I do the right thing.. I cut into a live Romex wire that was going from a switch to a light fixture. I was getting ready to connect the fixture and was shortening the wire with my linesman. It created a spark and tripped the breaker. I turned the breaker off and went finished cutting the wire. I cut it back an inch or so from the spot I cut. I connected to the fixture and now it's not getting power. I tried another fixture and still no power. Could I have ruined the whole wire? Or is the switch possibly fried? I'll try a new switch tomorrow, but if that works do I need to be worried about the safety of the wire? Hate to run a new one but I don't want to compromise safety.
Thanks
Thanks

#2
If any of the connections are back stabbed they need to be moved to the screws. Any wire nut connections need to be redone and the inside of the wire nut inspected. Dimmers are prone to being fried but regular switches are less likely to be damaged. To check remove the wires from the switch and connect together with a wire nut.
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Thank you. If the wire ends up okay I want to be sure it's safe to use. There are no wire nuts other than the common and grounds in the switch box. I'll double check those. The switch is a lutron digital dimmer so my suspicion/hope is that it's the culprit.
#4
You haven't hurt the wiring. Copper wiring can take a lot of current. If your breaker tripped it'll be fine.
I was on a demolition job a month ago. I cut a piece of 12/3 MC (metal clad with copper wires) with my semi new Klein side cutting pliers. The 208v 20a 3 phase breaker never tripped.
Wire survived just fine.... the pliers have a large hole where the cutter should be.
I was on a demolition job a month ago. I cut a piece of 12/3 MC (metal clad with copper wires) with my semi new Klein side cutting pliers. The 208v 20a 3 phase breaker never tripped.

Wire survived just fine.... the pliers have a large hole where the cutter should be.
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Lol I made a pair of those when I was about 5 years old.. Cut a live extension cord with them and got knocked on my ass... Still have them too. I swiped them from my dad when I moved out because the notch is such a perfect stripper..

And there's a reason the tips used for welding steel are made of copper..
The problem is almost certainly the dimmer. The electronics inside are not tolerant of shorts whatsoever, and would have fried instantly.


And there's a reason the tips used for welding steel are made of copper..

The problem is almost certainly the dimmer. The electronics inside are not tolerant of shorts whatsoever, and would have fried instantly.
#7
The wires in the wall were almost certainly not harmed.
But if there were other outlet boxes daisy chained upstream along the line and some of the switches or receptacles were connected using the "push-in-and-it-sticks" (backstab) connections with both the incoming and continuing cables, it is possible one of those connections went bad during the short circuit.
They (Ideal and Wago among others) also make rectangular "push-in-and-it=sticks) wire nuts. Some experts say that these can withstand a short circuit downstream but I am suspicious.
But if there were other outlet boxes daisy chained upstream along the line and some of the switches or receptacles were connected using the "push-in-and-it-sticks" (backstab) connections with both the incoming and continuing cables, it is possible one of those connections went bad during the short circuit.
They (Ideal and Wago among others) also make rectangular "push-in-and-it=sticks) wire nuts. Some experts say that these can withstand a short circuit downstream but I am suspicious.
Last edited by AllanJ; 01-28-14 at 04:58 AM.
#9
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Sorry if I wasn't clear. I was making the the length of the wire shorter, not intentionally creating a short. I was installed a light fixture and although there is no reason to be careless, I was in a hurry and was in the attic where it was cold and just wasn't thinking straight apparently. I went to cut the wire to the proper length before I connected to the fixture. It popped and sparks flew
, but surprisingly I didn't feel anything and my pliers appear to be fine, only suffering a slight burn mark. I've been told not to fear electricity but to respect it. I shouldn't have been working on it without the breaker turned off. Lesson learned. :NO NO NO:
I appreciate all of the feedback and stories though! Makes me feel a little better about what I did
I'll go exchange the dimmer tonight and switch that out (With the power off
) and hopefully that solves the problem.

I appreciate all of the feedback and stories though! Makes me feel a little better about what I did

I'll go exchange the dimmer tonight and switch that out (With the power off

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Sorry if I wasn't clear. I was making the the length of the wire shorter, not intentionally creating a short. I was installed a light fixture and although there is no reason to be careless, I was in a hurry and was in the attic where it was cold and just wasn't thinking straight apparently. I went to cut the wire to the proper length before I connected to the fixture. It popped and sparks flew ,
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You are actually very correct! I was up in the attic in a very uncomfortable place to get to. It's in a "new" side of the house, so to get there I have to crawl through a small opening in the studs that were holding up the old roof. Then, I was laying across some plywood that I had laid down across the joists which are 24" on center. I was laying all the way against where the roof meets the wall in the attic, so I had about 2" head room even when laying down. I was in a strange position that even the most experienced yoga professional would envy. When I hit the wire, I jumped and actually smacked my head against the roof. So, yes, it would have actually been much easier to just short it out instead of having to crawl all the way back out, down the attic hatch and into the basement to flip the switch. 
Also, I was freezing my butt off since the outside temp w/out windchill was -15! I'll blame that for my lack of thinking clearly

Also, I was freezing my butt off since the outside temp w/out windchill was -15! I'll blame that for my lack of thinking clearly

#12
Shorts happen.
I had a maintenance job in a large hotel. I had a fork with a prong cut and tape around the handle I called "the circuit tracer".
I had a maintenance job in a large hotel. I had a fork with a prong cut and tape around the handle I called "the circuit tracer".

#13
I had a fork with a prong cut and tape around the handle I called "the circuit tracer".



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So how does that work? you put electrical tape around the handle of the fork. and then remove all but one prong of the fork. Insert it into the outlet and then the breaker will turn off.... Im going to have my 5 year old try one out for me this weekend. he's always wanting to help dad around the house. Unless you think this is unsafe?
Mod Note: shorting a device like this is not a safe practice.
Mod Note: shorting a device like this is not a safe practice.
Last edited by pcboss; 01-31-14 at 03:55 PM.