Use it or toss it? Soggy NM (Romex) wire

[Barry Mabery]

The GC on my new country house construction left 200 feet of "slightly used" #12/2 with ground NM (indoor type) that I believe they had as a cable from the temporary service to the house last winter. It looks OK (just a little dirty - no damage to the insulation) and checks OK with my ohm meter. I needed about 25 ft. for a new 20 amp circuit and had used all of my new cable. I cut off a piece of this and when I stripped it, the paper around the solid ground conductor was wet. I mean it literally disintegrated. Should I scrap the entire amount or can it be used? Will it ever dry out?

[Marty Tippin]

Where did you cut the piece from? Near the end or the middle? If it was at one end, just start cutting back a few feet at a time until you find dry paper. If you get to the other end of the cable before you find dry paper, you know it wasn't good for anything...

[Barry Mabery]

The GC on my new country house construction left 200 feet of "slightly used" #12/2 with ground NM (indoor type) that I believe they had as a cable from the temporary service to the house last winter. It looks OK (just a little dirty - no damage to the insulation) and checks OK with my ohm meter. I needed about 25 ft. for a new 20 amp circuit and had used all of my new cable. I cut off a piece of this and when I stripped it, the paper around the solid ground conductor was wet. I mean it literally disintegrated. Should I scrap the entire amount or can it be used? Will it ever dry out?

[Dan Hulbert]

I wouldn't take the risk. I'm not currently an Electrician, but some things don't seem worth the risk. I recall from my USN electricians mate days (nearly 40 years ago) that there is a way to check the insulation resistance to ground, but I doubt you have the tool to do it. It was a Meg Ohm Meter and it could put 500 volts on the conductor and you could read the resistance to ground. Results needed to be rather high to be acceptable. The key to the validity of the reading was the voltage, most multi-meters only put out a couple of volts when they check resistance. Enough for continuity checking, but not enough to verify the integrity of the insulation.

[Michael Stein]

I wouldn't take the risk. I'm not currently an Electrician, but some things don't seem worth the risk. I recall from my USN electricians mate days (nearly 40 years ago) that there is a way to check the insulation resistance to ground, but I doubt you have the tool to do it. It was a Meg Ohm Meter and it could put 500 volts on the conductor and you could read the resistance to ground. Results needed to be rather high to be acceptable. The key to the validity of the reading was the voltage, most multi-meters only put out a couple of volts when they check resistance. Enough for continuity checking, but not enough to verify the integrity of the insulation.


I don't know the answer, but I agree with this guy. I wouldn't take the risk.

[Mike Henderson]

If I had the wire, I'd use it. The insulation that matters is the plastic insulation around the current carrying wires and that won't be affected by getting wet. The paper around the ground wire doesn't matter much. I might let it sit in the sun for a while but it may take a very long time to dry out.

This is assuming the wire is not abraded or damaged in any way except getting wet.

I'd use it. But that's me. If you have any qualms about it, don't use it. The worry is not worth it.

Mike

[Barry Mabery]

The piece I used was about 50 ft. into the "reel". Don't have access to a Meg Ohm and, although the moisture shouldn't be able to get into the two insulated wires, I would rather scrap it than have any problems.

Thanks all

....and sorry about the double post - interrupted by a phone call and couldn't remember if I'd hit "submit" - guess I had.

[Larry Browning]

I don't know, but before I gave up on it I would get to opinion of an actual electrician. Have him look at it and tell you the risks (if any).
BTW: how much would that much wire cost these days?

[Wade Lippman]

It is probably fine, but wire is cheap and time is expensive. I would hate to find out afterwards why I shouldn't have used it.

[Robert Engel]

I'm with Mike. I would use it. The wire is insulated.
I see electricians trucks with wire in the back all the time it must get wet some time or another.

How much does 50' of wire cost? If it give you piece of mind its worth it.

[Tom M King]

It's probably fine, but I'd hang it in a shed, and use it sometime on a future project if it didn't stink after it dries out.

[Jeff Fischer]

I was faced with the same question a few years ago when a sub left 100' of 10/2 NM laying on a jobsite. He had run it to a compressor from the temp pole to the backyard.
When I picked up the discarded wire to take it home, my Electrician warned me not to use it, even after it dried (if it ever did), due to corrosion attacking the ground wire and possibly causing a break in the ground path. Might not cause a fire, but might kill somebody.
He also said that's why Nm in conduit outdoors or in damp area has to be weathertight: to protect the paper from absorbing miosture.
HTH,
Jeff

[Mike Henderson]

I was faced with the same question a few years ago when a sub left 100' of 10/2 NM laying on a jobsite. He had run it to a compressor from the temp pole to the backyard.
When I picked up the discarded wire to take it home, my Electrician warned me not to use it, even after it dried (if it ever did), due to corrosion attacking the ground wire and possibly causing a break in the ground path. Might not cause a fire, but might kill somebody.
He also said that's why Nm in conduit outdoors or in damp area has to be weathertight: to protect the paper from absorbing moisture.
HTH,
Jeff
The ground wire is copper which is pretty resistant to corrosion. It's hard for me to visualize that copper wire corroding to the point where you'd have an open ground. It's hard for me to even visualize the loss of a significant amount of copper to corrosion in this situation.

I've pulled bare copper out of the ground and, except for being dirty and maybe having a lot of stuff stuck to it, it was fine. We use copper wire and copper rod for grounding and it sits in the ground in all kinds of weather, essentially alway wet and it last forever.

Unless there's something about the paper that caused the wet paper to emit some chemical that would corrode copper, I don't see how the wire would corrode. And it's hard to see how the standards bodies would allow such a situation. Houses occasionally have leaks, such as roof leaks, and the wire gets wet. Often when they repair the roof, they never look below the roof. It would be unsafe if the paper caused severe corrosion when it got wet.

Mike

[Frank Pratt]

I am an electrician. When Calgary had a big flood a couple of years ago the inspection authorities were calling for any cable that was submerged to replaced. Interesting fact about the insulation inside NMD90 is that it's T90, which isn't approved for use in wet locations, such as underground conduit that might be filled with water. It is not as moisture resistant as x-link insulation. So personally, I wouldn't use it. But from a practical stand point, if you megger it & it tests OK, it should be fine.

I don't buy the line about the ground wire corroding away to nothing though. bare copper wire will last underground for decades if not centuries.

[Dan Hintz]

Take a look at this paper from UL: http://www.ul.com/global/documents/offerings/perspectives/regulators/electrical/flooding/UL_Floodwater_Brochure_2009.pdf

(http://www.ul.com/global/documents/offerings/perspectives/regulators/electrical/flooding/UL_Floodwater_Brochure_2009.pdf)Here is a quote from it:

In general, cables with PVC insulation and jacket can withstand immersion in clean water for a short period of time without being damaged as long as the ends are not immersed. If the ends of the cable are immersed for any period of time, however, the internal paper wrapping around the bare equipment-grounding conductor will absorb and transfer the water into the cable assembly. The water may then start degrading the insulation or possibly corrode the
conductors. If the cable comes into contact with contaminated water, the contaminants may also act on the insulation or conductors. Over time, failures can occur.




There are multiple reasons for the paper. It allows the sheath to retain its shape, it allows for the wires to more easily slide past each other during twisting/bending (as well as preventing the outer sheath from attaching itself to the inner insulation during manufacture), and it acts as a stopgap measure during water intrusion (it will swell and prevent too much water from entering too fast, but it's not a complete preventative measure, given enough time to soak).

In the end, however, using it is against code:

110.11 Deteriorating Agents. Unless identified for use in the operating environment, no conductors or equipment shall be located in damp or wet locations; here exposed to gases, fumes, vapors, liquids, or other agents that have a deteriorating effect on the conductors or equipment; or where exposed to excessive temperatures.

[Steve Milito]

Is it really worth the risk to save $10 - $15?

[Robert Engel]

I'm with Mike again. Ground rods are copper coated steel, not even solid copper.

I think there has to be some type of electrolysis going on for the copper to degrade.

Reading the quote by Dan, I can't envision PVC insulation degrading if water pipe is made of it.

I'm just talking from common sense perspective I'm sure the experts have a reason to say that.

[Frank Pratt]

Good info Dan.

[Dan Hintz]

Reading the quote by Dan, I can't envision PVC insulation degrading if water pipe is made of it.

There are many grades of PVC (or any other plastic), as well as fillers and other additives to give the different properties needed for each application. Just because something's main ingredient is PVC doesn't mean it has the same properties as the next item.

Acrylic, for example, has vastly different properties depending upon whether it was cast or extruded... same basic formula, though.

[Rollie Meyers]

NM cable "Romex®" is only allowed to be used in dry locations, the OP's cable has been used outside it's allowed usage, scrapping it is in my opinion the only proper option.

[Barry Mabery]

I think Dan's first reply is salient and I had already decided to NOT use the cable. After all it's NM and not UF and I'm uncomfortable having the water migrating so far into the coil.
Thanks,

Barry

[Scott Austin]

I have used scrap romex for bunch of other uses. It makes a great temporary bunge's cord, cut off section to use as caulk poker ( I wrap a section on my caulk gun )