Type mc, nm romex.

[bgelectric]

What type of insulation does12/2 romex have on the individual wires? same with 12/2 mc? is it thhn?

 

[Cavie]

That's the roomer!

 

[480sparky]

It can be any type of 90?C conductor.

 

[augie47]

but, unfortunately, only a rumor
It is an insulation that meets the UL specs for Romex (or MC) and is not necessarily a THHN or THWN, so if you strip the outerjacket and use the inner conductors you are the the mercy of the inspector.

 

[romex jockey101]

romex is thhn and will tell u on conductor..

 

[curt swartz]

If you read the specifications of most branch circuit MC cable it will state the conductors are type THHN. I have never seen any manufacture state the conductor type in NM cable.

 

[roger]

romex is thhn and will tell u on conductor..

No it's not, look at another role of NM.

Roger

 

[PetrosA]

romex is thhn and will tell u on conductor..

not necessarily

If you read the specifications of most branch circuit MC cable it will state the conductors are type THHN. I have never seen any manufacture state the conductor type in NM cable.

No it's not, look at another role of NM.

Roger

also not necessarily

I was checking NM specs a few days ago because someone asked on another forum why we don't use stranded wire cables for building in the US and I wanted to find out if solid wire was part of the NM-B spec or not. I didn't find that per se but I did find that at least one manufacturer uses (or claims to use) THHN in their romex type cables and another claims the insulation meets the THHN spec but doesn't call it THHN.

From Southwire (original "Romex" manufacturer):

"Conductor insulation is 90?C-rated polyvinyl chloride (PVC), nylon jacketed."
So we don't know what it is.

From United Copper Industries:

"Type NM-B cable is manufactured as 2- or 3- conductor (Type THHN/THWN-2) cable, with a ground wire."
I don't know how they label their conductors, but since their spec sheet makes this claim, you have an argument for THHN.

From Pittsburgh Wire:

"Conductor insulation is 90?C-rated polyvinyl chloride (PVC), nylon jacketed, colorcoded for identification purposes."
Not THHN

From Nexans:

"Color coded polyvinyl chloride (PVC) compound with a nylon jacket meeting the required thickness of Type THHN."
Blurry... Meets the specs, but isn't the same?

None of the specs I saw mentioned how the wire was marked.

 

[roger]

also not necessarily

Yes, neccessarily, find us an example of the conductors inside the jacket of NM identified per the requirements of 310.11 and you'll have a valid point, until then the conductors inside the jacket of NM are simply 90 deg conductors that must be used as 60 deg conductors.

So we don't know what it is.

Correct.

Roger

 

[LarryFine]

romex is thhn and will tell u on conductor..

Never seen it. MC, yes; NM, no.

 

[PetrosA]

Yes, neccessarily, find us an example of the conductors inside the jacket of NM identified per the requirements of 310.11 and you'll have a valid point, until then the conductors inside the jacket of NM are simply 90 deg conductors that must be used as 60 deg conductors.

Correct.

Roger

I can't say with 100% certainty that there isn't some company out there making a NM-B cable with THHN markings on the wires. Since one person seems to think they saw that, and I found a company that claims they use THHN for the conductors, I have to leave room for the possibility.

 

[roger]

I can't say with 100% certainty that there isn't some company out there making a NM-B cable with THHN markings on the wires. Since one person seems to think they saw that, and I found a company that claims they use THHN for the conductors, I have to leave room for the possibility.

I await the proof, but I won't hold my breath. Since most companies that make NM also make single conductor types, why would they cut their own throats?

Roger