What is INSIDE Romex?

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LaCanaria

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What is inside Romex? I've always heard it was THHN, but I can't find that stated definitively on our submittals. Our submittals only say "conductor insulation is 90 degree C rated PVC, nylon jacketed.." then in another part says "insulated witha tough heat and MOISTURE RESISTENT PVC. . ". All that would be consistent with THHN.
So, it could not be THWN, (WET LOCATION) right???
 
LaCanaria said:
What is inside Romex? I've always heard it was THHN, but I can't find that stated definitively on our submittals. Our submittals only say "conductor insulation is 90 degree C rated PVC, nylon jacketed.." then in another part says "insulated witha tough heat and MOISTURE RESISTENT PVC. . ". All that would be consistent with THHN.
So, it could not be THWN, (WET LOCATION) right???
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It is not important what the individual conductors inside of NM cable actually are. These conductors are not intended to be used 'outside' of the overall NM jacket. NM is not rated for wet locations. NM-B internal conductors are rated 90?C.

Do you have a specific issue you are trying to address?
 
i know, but

i know, but

I'm bidding a job in Houston. Under the unit panels, it says ALL WIRE IS THWN #12 MINIMUM. Under the clubhouse and house panels, it says the same except IN 1/2" MIN CONDUIT PVC.
I'm getting out bid by others because I've got everything in THWN in conduit since ROMEX is NOT suitable for wet locations and the plans call for THWN.
 
wet locations only at A/C locations on roof

wet locations only at A/C locations on roof

The only wet locations are at the A/C condensors on the roof. I sent an email to the engineer and asked if perhaps the THWN on the unit panels and clubhouse panel drawings was a typo and if he would allow NM-B. Thanks for all of y'alls input. Would somebody look at my posting earlier today about the cold water ground. Sure would appreciate it!
 
Cavie said:
. . . Thhn for sure. . .
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Sorry, I don't agree. It is up to the manufacturer and they can change from day to day if they wish as long as they meet the listing requirements for Type NM cable. By the way, I have yet to see Type NM cable with conductors that have a nylon coating on the outside of the conductors. Does that make it THH instead of THHN (I guess it does exist though)? :)
 
charlie said:
Sorry, I don't agree.
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I think that Cavie was specifically talking about the Phelps-Dodge product that I linked, not NM in general. If a company tells me that _their_ NM-B contains THHN conductors, then I believe that they are required to supply NM-B with actual THHN conductors, not 'conductors that generally meet the requirements of THHN'.

To be fair, however, that PD sheet doesn't say anything about THWN, yet it does clearly state a 75C temperature limitation for wet conditions; I wouldn't trust that datasheet without further confirmation from the company.

-Jon
 
LaCanaria said:
What is inside Romex? I've always heard it was THHN, but I can't find that stated definitively on our submittals. Our submittals only say "conductor insulation is 90 degree C rated PVC, nylon jacketed.." then in another part says "insulated witha tough heat and MOISTURE RESISTENT PVC. . ". All that would be consistent with THHN.
So, it could not be THWN, (WET LOCATION) right???
Click to expand...

Even if romex did contain and the conductors labeled thwn it still would not be code compliant to install it outdoors in a wet location. Art. 334.12(B)(4)
 
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