# Screw into wiring



## Master Brian (Apr 24, 2009)

The other day I was running a screw into a stud and nicked lightly nicked an electrical line and thus tripped the breaker.

I cut back the insulation/sheathing on the romex wire to inspect and apparently what I hit was mostly the ground wire. There is a small nick out of it, but other than that, couldn't really see any other damage to the remaining wires. The neutral wire was definately not affected as the screw was on the hot wire side, but guessing that the screw must have just lightly nicked the insulation on the hot wire with the thread or tip of the screw. 

My question is, is there a safe way to repair this wire WITHOUT having to relace the entire length of wire. As soon as I insected the wires, I flipped the breaker and all was fine again. As a temp safety measure I did wrap the wires with electric tape just to ensure nothing hit them, but if that's not safe then don't want to leave them like that. My biggest concern is the small nick it took out of the ground wire as I don't know what that will do over time. 

Thanks for any feedback....


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## rrolleston (Oct 17, 2011)

Master Brian said:


> My question is, is there a safe way to repair this wire WITHOUT having to relace the entire length of wire.


Installing a junction box or two to properly splice the two ends together with wire nuts and covering them with blank plates so they can always be accessed.


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## Msradell (Sep 1, 2011)

rrolleston said:


> Installing a junction box or two to properly splice the two ends together with wire nuts and covering them with blank plates so they can always be accessed.


 Just remember that any boxes you install have to remain accessible! They cannot be hidden within the wall.


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## frenchelectrican (Apr 12, 2006)

Just before you mudded up the drywall please do the proper repair first either use two junction boxes as other mention otherwise if that is a short run just replace the entire length.

And what size screw you did used ?? if you useing to run the drywall screw you only need 1.25 inch drywall screw that will serve very well.

I have ran into like this pretty often when someone use more than 1.5 inches ( the last one I did see was a good 3 inch drywall screw it took out the house service entrance cable  ) 

Make sure you keep your romex cable in centre much as possible so that way the drywall screw or nail will not hit them.


Merci,
Marc


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## rrolleston (Oct 17, 2011)

frenchelectrican said:


> I have ran into like this pretty often when someone use more than 1.5 inches ( the last one I did see was a good 3 inch drywall screw it took out the house service entrance cable  )


Ouch lucky their house is still standing. Must have been a mess.


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## frenchelectrican (Apr 12, 2006)

rrolleston said:


> Ouch lucky their house is still standing. Must have been a mess.


Yeah but it was a super mess to clean it up have to rip the drywall off to get into the rest of it to make it worst it was allready in the PVC conduit that how it did reduce the damage if not have conduit in there just a plain jane SE cable it will do more damage there.

That was just a stroke of luck on that time and it was good thing the POCO transfomer allready at full load so a good short did blew the fuse out so that is the other factor it was lucky.

Not very often you get that kind of combation of luck at once.

Merci,
Marc


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## Master Brian (Apr 24, 2009)

As for the screw, it was acutally a 3" - 3-1/2" screw, as I was joining two 2x's together. Thought I was running the screw at more of an angle to avoid the wire, but ended up sinking in deaper at the last second and nicked the wire. 

The only real good news is that the wall was freshly stripped of Lathe and Plaster, so everything is exposed. I would love to replace the entire length of wire, but one end is in an unaccessible ceiling filled with cellulose insulation. This is 14/2 wire going from a switch to ceiling lights.

Not really anywhere good to place a junction box, unless I added one inside of a cabinet. The other option if it's ok to do, I could possibly use a nearby receptacle's box and tuck the wire into the back of that box, then put the receptacle, which is on different circuit back in. All that would require is running a new length of wire from switch to receptacle.


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## rrolleston (Oct 17, 2011)

Having two different circuits joined in one box could be dangerous for someone working on it in the future.


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## jbfan (Jul 1, 2004)

rrolleston said:


> Having two different circuits joined in one box could be dangerous for someone working on it in the future.


Not a problem and is done all the time.

If that is what works out best for him, go for it.
Of course, you need to make sure the box is large enough to handle the extra wires.


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## rrolleston (Oct 17, 2011)

jbfan said:


> Not a problem and is done all the time.
> 
> If that is what works out best for him, go for it.
> Of course, you need to make sure the box is large enough to handle the extra wires.


Not a problem if they are on the same breaker. If they are separate circuits then someone could get a surprise if they think everything in there is turned off.


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## jbfan (Jul 1, 2004)

rrolleston said:


> Not a problem if they are on the same breaker. If they are separate circuits then someone could get a surprise if they think everything in there is turned off.


That would then be their fault for not checking everything!!!!!!!


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## Yoyizit (Jul 11, 2008)

rrolleston said:


> Installing a junction box or two to properly splice the two ends together with wire nuts and covering them with blank plates so they can always be accessed.


Yes, you need two to lengthen the wires to give you the required 6" of leads in the box.


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## ddawg16 (Aug 15, 2011)

Master Brian said:


> The other day I was running a screw into a stud and nicked lightly nicked an electrical line and thus tripped the breaker.
> 
> I cut back the insulation/sheathing on the romex wire to inspect and apparently what I hit was mostly the ground wire. There is a small nick out of it, but other than that, couldn't really see any other damage to the remaining wires. The neutral wire was definately not affected as the screw was on the hot wire side, but guessing that the screw must have just lightly nicked the insulation on the hot wire with the thread or tip of the screw.
> 
> ...


Ya know....I will most likely catch hell for this....but....since you did not actually break the wire...in other words, it's fully intact....tape sounds like a sound solution...

If it was me....I would pull back the sheath on the Romex...tape the black real good...put the romex sheath back in place...tape the crap out of that...put back in wall....seal up said wall.....

There is no break....hence, no danger of a bad connection....


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## Yoyizit (Jul 11, 2008)

First, read this site's disclaimers.

Then collect the opinions, facts and reasoning of experienced electricians who object to the method below and then modify the method accordingly.
Posting the reasoning may turn matters of opinion into matters of fact.

To reduce your risk of fire to a level that is down in the noise, surround the repair with two halves of a 3/4" ID length of copper pipe split lengthwise and fastened with a hose clamp. You'll have to splay out one of the pipe pieces so you get some overlap between the pieces.

And to fasten the tape with some fireproof cord/strand/fine wire to prevent it from unwinding without using knots, search on "whipping" which is used to prevent the ends of ropes from fraying.


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## Master Brian (Apr 24, 2009)

ddawg16 said:


> Ya know....I will most likely catch hell for this....but....since you did not actually break the wire...in other words, it's fully intact....tape sounds like a sound solution...
> 
> If it was me....I would pull back the sheath on the Romex...tape the black real good...put the romex sheath back in place...tape the crap out of that...put back in wall....seal up said wall.....
> 
> There is no break....hence, no danger of a bad connection....


Well, that is what I've for now, but curious what problems that might pose. Really the only real issue I see is if the nick on the ground wire were to cause the ground wire to break, which would leave the lights this goes to without ground. There was no apparent damage to the other wires, other than a nick in the insulation. 

With that said, it isn't too much work, if I were to cut the wire and run a new wire from the switch to the receptacles junction box. Problem is I really question if creating a splice is really better than leaving as is, is there really much chance of the nick to the ground wire causing it to break? I would think that might only happen if the wire were to get overtly hot many times over many years. This serves 3 pendant lights and that is it, with most likely never more than 180-200w total. Even then, if it were to break, I'd just be without ground, which I do realize isn't necessarily a great thing, but....how great is that chance? 

In any case, it does bug me a little, so I'll likely splice and stick in junction box, even though like I said, I question that as I've seen those splices go bad and actually had one almost catch my house on fire right after buying the house. 

As for two circuits in one box, I tend to somewhat agree, if someone isn't smart enough to test all wires in a box, maybe they shouldn't be in there, especially since there will then be two different gauges of wire inside the box.


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## silversport (Feb 4, 2012)

If the wire is nicked, I personally would not feel comfortable taping it and sealing the wall up. I like using the nearest outlet as a junction box. Maybe note on the back of the outlet cover with a sharpie why the splice is there and where the wires go.....


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## ddawg16 (Aug 15, 2011)

Brian.....your asking some good questions....

I have a lot more electrical experience with control systems vs residential.....in what I do, the less connections, the better. 

With that said....wire nuts have proven to be very reliable.....but as noted above, they have to be placed an an accessable box.

Just how nicked is that ground wire? If the nick is less than 25% (leaving 75% or more of the wire intact), I would not worry about it....the ground is not a current carrying conductor....and once it's all patched up...it's not going to be moving.

What Yoyizit was suggesting is a good way to protect the wires once they are taped.....

But this is just my opinion....all disclaimers noted.....


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## jbfan (Jul 1, 2004)

If you tripped the breaker when you inserted the screw, you broke the insulation of the hot wire and made contact with the ground.

Forget about tapping and repair it properly.

A nicked wire will overheat without much load.
The electrons flow on the surface of the wire.


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## silversport (Feb 4, 2012)

Another point of view.... Be Honest, If you opened up a wall in your house and found the same thing as done by a previous owner (broken insulation, taped up, nicked ground, repair completely inaccessible) would you be annoyed?


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## ddawg16 (Aug 15, 2011)

silversport said:


> Another point of view.... Be Honest, If you opened up a wall in your house and found the same thing as done by a previous owner (broken insulation, taped up, nicked ground, repair completely inaccessible) would you be annoyed?


Good point....but then again, I think I would be more annoyed with junction boxes with no use.....other than to splice wires.....

Makes you wonder why they make splice kits for underground wires.....


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## secutanudu (Mar 15, 2009)

Jb is right - there is no way you didn't break through the insulation on the hot wire. The only way a screw would cause a breaker trip is a short between the hot and either the neutral or ground.

Do not tape it, you are asking for a disaster.


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## <*(((>< (Mar 6, 2009)

If your nearest outlet boxes are large enough to handle the wires (box fill) then I would be using them as junction boxes. But I would however note it on the back of the receptacle cover plates as well as at the panel, with the circuit in question. 

When you have two different circuits sharing the same box the grounds must be tied together (unless it is an isolated ground circuit, which yours is not).


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## Master Brian (Apr 24, 2009)

Thanks for the replies, they have helped a lot.....

Yes, I'd be a bit peaved if I came across a patch like this and I actually have came across similar things as it used to be common with knob & tube, like my house had some of....

Still not sure the wire nut is safer than leaving an unhurt wire, I can't be 100% certain, it didn't take a nick out of the hot, so I think I'll likely re-run some new wire and use the the j-box for the outlet. Thanks for sharing about the grounding, didn't realize that. I'll also try to remember to mark the cover, I have actually been trying to label everything I've touched over the years, as it does help later on.

If anyone else has anything to add, I'll be sure to pay attention, otherwise, thanks again!!


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## Techy (Mar 16, 2011)

They make a concealable splice kit for romex, similar to the underground splices. 

http://www.amazon.com/Tyco-Electronics-Cpgi-1116377-2-Non-metallic-Splice/dp/B0035L12KS


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## ddawg16 (Aug 15, 2011)

Techy said:


> They make a concealable splice kit for romex, similar to the underground splices.
> 
> http://www.amazon.com/Tyco-Electronics-Cpgi-1116377-2-Non-metallic-Splice/dp/B0035L12KS


 
To some small extent, I feel vindicated....thanks Techy...

With that said....while I agree with doing things right.....in this case, it was a simple screw point going through the insulation and making contact with the hot conductor...

In the 'real world', it is common to take ones meter probes with their sharp points and push them through the insulation to make voltage measurements...the insulation is resiliant enough to close up the hole and effectively seal the wire....

This is what most likely happened to the OP....hence, some tape is more than enough to make it very safe....

Sorry...but some of the 'opinions' above sound to me to be about par to "You have an oil leak. We have to replace the engine to fix it."


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## secutanudu (Mar 15, 2009)

Master Brian said:


> I can't be 100% certain, it didn't take a nick out of the hot


If your breaker tripped, you can be 100% certain that you DID take a nick out of the hot.


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## silversport (Feb 4, 2012)

.....


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