Electricians: How to repair nicked line?

[Miramonti]

While putting in a security cam recently, I nicked a line while drilling a hole. Fortunately, the bit scraped just one side and not dead in the middle. What should I do to secure or repair this properly?

 

[Red Squirrel]

Proper way is to put in a junction box and do a splice. If it's an accessible area and not a wall that had to be opened up the jbox is best bet. If it's an inaccessible location (Ex: plan to drywall over) the junction box will need to be accessible and have a plate. That might not be ideal aesthetically based on location. Since the wire is still intact, you could get away with just wrapping a whole bunch of electrical tape, and maybe some zip ties or something to keep it tight, but that would not be an approved way.

If that's actually an attic, I'd be more concerned about the lack of insulation.

 

[Miramonti]

Proper way is to put in a junction box and do a splice. If it's an accessible area and not a wall that had to be opened up the jbox is best bet. If it's an inaccessible location (Ex: plan to drywall over) the junction box will need to be accessible and have a plate. That might not be ideal aesthetically based on location. Since the wire is still intact, you could get away with just wrapping a whole bunch of electrical tape, and maybe some zip ties or something to keep it tight, but that would not be an approved way.

If that's actually an attic, I'd be more concerned about the lack of insulation.

Thanks, Red Squirrel. This is an exposed wire pinned to a 2x4 on the floor of the attic. Its above the entrance to the garage, so insulation is not as significant here, and I'd rather have the space open for storage .

I understand a junction box, but regarding splicing, what's the best way to do that? Should I snip out the damaged area, add a few inches of replacement wire by using wing connectors, and then stuff that all in the box...done?

 

[olds]

I can't tell from the picture, is that a single strand of wire?

 

[NetWareHead]

We need to now what kind of wire that is. Assuming it is electric, the proper and safest way is to create a splice in a junction box. Or replace the cable; run a new one. You have bare copper exposed.

 

[Greenman]

It looks like the hot wire in a piece of romex. Inspect it carefully, if just the insulation on one wire is nicked you can tape it up. If you're even a little concerned do it the proper way as RC suggested.

 

[Charmonium]

What's wrong with liquid electrical tape?

http://www.amazon.com/Star-brite-Liquid-Electrical-Tape/dp/B00U2JALTE

 

[olds]

It looks like the hot wire in a piece of romex. Inspect it carefully, if just the insulation on one wire is nicked you can tape it up. If you're even a little concerned do it the proper way as RC suggested.

Maybe it's the angle but that looks round to me.

 

[DrPizza]

With a non-contact tester, make sure you flip the breaker then inspect that line carefully. Inspect the copper - if the copper hasn't been damaged, and only the insulation, I'd just tape it up with electrical tape. However, that is not code compliant. And, you shouldn't just use the cheap electrical tape. It seems to me that you'd have to carefully strip the insulation around the wire a little bit to really inspect for a damaged wire. You don't want a nick causing the wire to eventually crack over time with seasonal changes in temperature.

The safest thing to do is either replace the whole line, else use junction boxes. Plural. I'm curious how people could put in "a" junction box, unless there's a lot of slack in the line. You would need two junction boxes. Otherwise, how are you going to have enough wire in the box?

300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points.
At least 150 mm (6 in.) of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or the connection of luminaires or devices. Where the opening to an outlet, junction, or switch point is less than 200 mm (8 in.) in any dimension, each conductor shall be long enough to extend at least 75 mm (3 in.) outside the opening.
Exception: Conductors that are not spliced or terminated at the outlet, junction, or switch point shall not be required to comply with 300.14.

So, assuming you go in the sides of a junction box, with a width of 2 inches, you would need 10 inches of slack to meet code (6 + 6 - 2).

 

[Red Squirrel]

I understand a junction box, but regarding splicing, what's the best way to do that? Should I snip out the damaged area, add a few inches of replacement wire by using wing connectors, and then stuff that all in the box...done?

Yeah pretty much, if there's enough slack you should be able to do it all in one box. You'll need to cut it and then do a splice with wire nuts. The ground can just screw into the box.

If there is not enough slack you may need two boxes and a small lenght of romex between. It seems kinda overkill though but I think it's the only code legal way of doing it.

That wire does appear odd though, is it just the angle of the pic? I assume it's just multi conductor romex?

 

[Charmonium]

It sounds like he's going to have rewire his entire house before this thread is over.

 

[Red Squirrel]

It sounds like he's going to have rewire his entire house before this thread is over.

That would be the Mike Holmes way. "Nick in a wire? We need to replace the whole run! Oh what's that, mold? I think it's coming from the kitchen, bathroom, or roof, so we'll just redo all of those too to be safe! Oh look it that they drilled in a structural wall, uhh, let's just rebuild the whole house to be safe.

To be fair a Holmes on Homes episode would be pretty boring if all they did was splice a wire and call it a day.

 

[Greenman]

Maybe it's the angle but that looks round to me.

It could be, maybe it's 3 wire?

 

[mindless1]

Depending on how long the run is, it makes sense to me to just replace the whole length of wire, segment of that run, to an adjacent (existing) upstream junction box on the same circuit.

It's probably not even going to be hard to string in an attic and having the existing wire to pull it through. Then again I'm thinking in terms of the value of a piece of wire rather than the cost of buying a longer length if you don't have any, but you may need to buy wire anyway if you have NONE, if there isn't enough slack to do the junction box without adding some.

 

[Miramonti]

I can't tell from the picture, is that a single strand of wire?

Based on googling, it's similar to a standard romex 3-strand wire cable. (It looks to be more molded in plastic on the outside then some romex pics tho.) One of the hot wires is nicked from the outside edge, affecting only the insulation of the nicked strand, while only slightly scraping (but not compromising) the wire itself.

What's wrong with liquid electrical tape?

http://www.amazon.com/Star-brite-Liquid-Electrical-Tape/dp/B00U2JALTE

I've used liquid tape before and it turned to goo after a couple years. Is this common?

With a non-contact tester, make sure you flip the breaker then inspect that line carefully. Inspect the copper - if the copper hasn't been damaged, and only the insulation, I'd just tape it up with electrical tape. However, that is not code compliant. And, you shouldn't just use the cheap electrical tape. It seems to me that you'd have to carefully strip the insulation around the wire a little bit to really inspect for a damaged wire. You don't want a nick causing the wire to eventually crack over time with seasonal changes in temperature.

The safest thing to do is either replace the whole line, else use junction boxes. Plural. I'm curious how people could put in "a" junction box, unless there's a lot of slack in the line. You would need two junction boxes. Otherwise, how are you going to have enough wire in the box?
So, assuming you go in the sides of a junction box, with a width of 2 inches, you would need 10 inches of slack to meet code (6 + 6 - 2).

I might be able to create some slack by unpinning it in places, but otherwise it's not far from the wall leading shortly down to the box. The entire line is probably about 20-25' starting at the box, until it feeds into another junction box in the attic. I've added lines before from the box so it's doable, but given the tight spaces and extra work involved, I will probably avoid this since it doesn't sound essential.


I'm tempted to just seal it really well. If not standard electrical tape, which tape best?

I'll head to Lowes and check out junction boxes while there and weigh these approaches. I've put boxes in the wall for new outlets, so I should be able to figure out what's needed for a stand-alone enclosure (or two.)

 

[pcgeek11]

If you want to tape it use this:

http://www.homedepot.com/p/1-in-x-3...sing-Silicone-Tape-in-Black-1208952/100206050

Self seals a fuses to itself and is made of silicone. I have used this many times and found it to be an excellent product.

If not get two junction boxes and patch in a piece of cable.

 

[Charmonium]

If you want to tape it use this:

http://www.homedepot.com/p/1-in-x-3...sing-Silicone-Tape-in-Black-1208952/100206050

Self seals a fuses to itself and is made of silicone. I have used this many times and found it to be an excellent product.

If not get two junction boxes and patch in a piece of cable.

I completely forgot about the self-sealing tape. That stuff is amazing. I fixed a corroding U-trap with that stuff about 10 years ago and it's still completely dry. Saved my having to replace it even though it was nearly rotted through in several places.

 

[Humpy]

Based on googling, it's similar to a standard romex 3-strand wire cable. (It looks to be more molded in plastic on the outside then some romex pics tho.) One of the hot wires is nicked from the outside edge, affecting only the insulation of the nicked strand, while only slightly scraping (but not compromising) the wire itself.



I've used liquid tape before and it turned to goo after a couple years. Is this common?



I might be able to create some slack by unpinning it in places, but otherwise it's not far from the wall leading shortly down to the box. The entire line is probably about 20-25' starting at the box, until it feeds into another junction box in the attic. I've added lines before from the box so it's doable, but given the tight spaces and extra work involved, I will probably avoid this since it doesn't sound essential.


I'm tempted to just seal it really well. If not standard electrical tape, which tape best?

I'll head to Lowes and check out junction boxes while there and weigh these approaches. I've put boxes in the wall for new outlets, so I should be able to figure out what's needed for a stand-alone enclosure (or two.)

What exactly is "the box" that the wire connects to? The breaker panel?

What does the wire power on the other end?

The thick molded jacket on the wire is odd to me.

Regardless, just taping it up seems half-ass unless it's speaker wire or something.

 

[stormkroe]

If the copper was damaged, junction box. If it's a coax (top cable looks like one), just crimp 2 new ends on and get a coupler. Most people don't realize it would take a $300k piece of gear to detect a difference between continuous rg-6 and one that has been (properly) coupled.

 

[Miramonti]

If you want to tape it use this:

http://www.homedepot.com/p/1-in-x-3...sing-Silicone-Tape-in-Black-1208952/100206050

Self seals a fuses to itself and is made of silicone. I have used this many times and found it to be an excellent product.

If not get two junction boxes and patch in a piece of cable.

I've decided to use some liquid tape (with a new bottle), which seems like the best way to seal the wire perfectly from the outside and it's neighbor wire, and then some professional electrical tape on top of that (strong adhesive, high temp) once it cures. I like this tape over silicone self-sealing in this case because its more durable, particularly if stepped on (even though that's unlikely in this small space.)

The thing about doing it this [half-ass] way is that realistically, it will be plenty, but also I can redo it with junction boxes or a new line anytime if I change my mind.

 

[natto fire]

I've decided to use some liquid tape (with a new bottle), which seems like the best way to seal the wire perfectly from the outside and it's neighbor wire, and then some professional electrical tape on top of that (strong adhesive, high temp) once it cures. I like this tape over silicone self-sealing in this case because its more durable, particularly if stepped on (even though that's unlikely in this small space.)

The thing about doing it this [half-ass] way is that realistically, it will be plenty, but also I can redo it with junction boxes or a new line anytime if I change my mind.

What was the professional tape you used? In my trade, 3M 33+ is simply referred to as the "good stuff" and all the rest is known as "jap wrap". I think that term is from when Japan was set up to be the way China is to us now. Even 3M makes a cheapo tape called economy vinyl tape. It is much better than the cheap stuff from BLowes or Home Cheapo, but not by much, and the 33 is worth the premium if it is for a permanent use. I resort to the cheap crap when setting up THHN pulls, or fishing wires, but only use the 33+ if it is a serious use.

 

[mindless1]

^ Due to its inherent properties there will never be a vinyl electrical tape fit for permanent or serious use as insulation or repair of insulation. It may be cheaper and/or easier, but it's clearly not as permanent or safe as other standard wiring practices so how serious is it when it's inferior for a purpose?

 

[Miramonti]

What was the professional tape you used? In my trade, 3M 33+ is simply referred to as the "good stuff" and all the rest is known as "jap wrap". I think that term is from when Japan was set up to be the way China is to us now. Even 3M makes a cheapo tape called economy vinyl tape. It is much better than the cheap stuff from BLowes or Home Cheapo, but not by much, and the 33 is worth the premium if it is for a permanent use. I resort to the cheap crap when setting up THHN pulls, or fishing wires, but only use the 33+ if it is a serious use.

That's what I used, good to know. It gets over 130 degrees in the attic so I was worried about using regular tape.

 

[Miramonti]

^ Due to its inherent properties there will never be a vinyl electrical tape fit for permanent or serious use as insulation or repair of insulation. It may be cheaper and/or easier, but it's clearly not as permanent or safe as other standard wiring practices so how serious is it when it's inferior for a purpose?

I believe if there are conditions that make these layers inadequate, it's likely the least of my problems.

 

[NutBucket]

Agreed 100% 33+ really is the ducks nuts!