Blake

I have some leftover 6/3 Romex. If I remove the outer sheathing, I am left with (3) #6 wires and one uninsulated ground wrapped in paper. My question is: do the (3) wires have the same insulation as if I went and bought #6 stranded?

bobelectric

If it nm-2 which is thhn

raider1

The biggest problem with doing that, is that the wires within the sheath of NM-B are not individually marked as required by 310.11.

The suffix -B in NM-B denotes that the conductors within the sheath are rated at 90c, as required by 334.112. (Take a look at the fpn to that section)

Chris

Joe Momma

Nice post raider
especially with the obscure article included

__________________
Joe Momma was here

raider1

You liked that did you.

I am full of worthless information.

Chris

itsunclebill

I see a lot of references to the insulated conductors in NM-B being THHN. I haven't seen a nylon covering on a NM-B conductor for years. And, much of what I see doesn't appear to have the same "look" as multi-rated wire, such as THHN-THWN-THHW-MTW. The article 334.112 says that ANY conductor listed in table 310.13 can be used as long as it is 90° rated.

Back before wire prices went nuts it was often possible to buy 1000 ft of NM-B for a few dollars more than a 1000 ft of THHN. Something tells me the insulation costs had a lot to do with this as there is 3000 ft of wire in the NM-B......

John Valdes

There not THHN for sure. And are not marked as required. I am curious as to the temp rating of these conductors as individuals. I also do not see any thermoplastic coating that THHN or THWN has. I doubt they are rated for wet locations, oil or gas.

raider1

If the NM cable is marked NM-B the temperature rating of the conductors within the sheath will be 90c.

I agree that there is no way to know what type of conductors are installed within the sheath of the NM cable.

Chris

bigredc222

Just use it it will be fine. the price of copper these days. If you can save some bucks. It will be more protected in conduit that it would have been in NM. No one is going to pull it out of the pipe and say it's not marked. You guy's are splitting hairs. It will be fine.

raider1

If you install the conductors in a conduit on the exterior of the building, how will you know if the conductors are a type listed for use in a wet location?

Spliting hairs or not, 310.11 requires individual conductors to be marked with the voltage rating, letter type, AWG, manufacturer's name ect... The conductors within NM cable are not marked so we don't know anything about them, such as if they are suitable for use in a wet location.

Chris

gilbequick

Gotta tell ya, wether or not they'll be ok isn't relevant around here. If it's not marked it's a fail on the inspection.

If it's something that isn't going to be inspected I'd use it. If it's going to be inspected than save yourself the hassle and use thhn.

Blake

Thanks for all sides of the argument of it being good or bad. Just to clarify- It is going to be a 15' run outdoors from a GFCI box to a spa. (5' in conduit down the wall, 5' in conduit buried, 5' in liquidtite into the spa. What really had me wondering about major differences is the fact that 125' of 6/3 WG Romex ( 375 total feet of #6) is $222-or the equivalent of $.59/foot at Home Depot. That same 375' of individual THHN is $352.50 or $.95/ft. That does not include the 125' of bare copper #10 ground I could recycle/reuse or the cost that Romex has to put the NM-B jacket on the bundle which I reasoned probably cost more than ink jetting the individual THHN wires. I just wondered because of the 60% difference in price if there was some major difference. I guess it is the power of buying in bulk or one product getting price adjusted faster or slower than the other. Normally in a sellers market such as we are in with copper and nickel, the big guys do not get much better pricing than the little guys simply because sellers do not have to do it.

I realize there are marking issues and technicalities. But since an inspector will never look at it, I have a hard time throwing away good wire ,spending the additional $42.30 all over ink jetting and no technical or safety difference. If someone ever questions the size or type, all they would have to do is look at the inlet side of the GFCI box, and they would see that the NM-B is clearly marked 3 #6 CU, Ground #10, and the wires going out the other side are the same size, same jacket color, thickness and type. At least the #6 Green Ground , I will have to buy to replace the bare #10 will be marked. Thanks again for all of the thoughts/opinions. Please excuse the ignorant question.

Blake

I neglected to mention I live in unincorporated Harris County in Houston, TX. No codes, no permits, no inspectors, no zoning, no taste-the real wild west

Pierre Belarge

Then why even ask any questions???

itsunclebill

I've always believed that "splitting those hairs" is the difference between a professional installation and a hack job. If you are willing to ignore code rules because of convience and cost, where does it stop?

jproffer

I dunno about Blake, but I'm curious about alot of things that I don't HAVE to do, or HAVE to know, or HAVE to care about....I'm just curious...hunger for knowledge, desire for useless facts, call it whatever...it's just curiousity.

Blake

Well Pierre I wanted to make sure there were no other legitimate safety issues other than the ink jetting on the wiring. I agree if I were doing this job commercially for a paying customer who was going to be inspected, there is only 1 way to do it, by the book. This job does not fall into that category.

Mountain Electrician

There is only one category...by the book. The rules should not be different because no one's watching and knowingly violating the code is a slippery slope, like unclebill said, where does it stop?

As electrical professionals, our goal should be a craftsman like, code compliant installation every time, no matter what the circumstances. Most of us have or will have licenses that indicate we are competent in our trade, know the rules and will follow them.

It's true that installing the #6 from the NM-B will work. The spa will operate, it is GFCI protected, and ultimately there are no major safety issues, but it is still wrong.

That means you should be doubly on your toes, because you have no safety net... no inspector to catch something you might have missed, no second set of eyes helping you. You have to police yourself, and follow the NEC.

Even though you are in the great state of Texas, it is not it's own country. Texas now has a state licensing system for electricians (finally) and I assume somewhere there is a governing body and they must have a controlling document for electrical work, and I'd bet it's the NEC.

I live in an area that is similar inasmuch as there is no state permitting or inspections of residential electrical work. When you have people doing marginal and non-compliant installations, it makes it hard to compete as an EC who does follow the code. Explaining to a customer why they have to pay $15 for a in use cover when the last guy used a $4 cover is tough. Saving $42.30 is great, but you are teaching customers that corner cutting is normal and acceptable.

raider1

There is no requirement for the conductors within the NM cable be suitable for use in a wet location, so the conductors within the NM cable might only be suitable for use in a dry location (Such as THHN). Again I would not use the conductors from the NM cable in a conduit in a wet location.

Chris

John Valdes

Buried. NM covered or not is not rated for wet locations. Anything buried is considered a wet location.