NM Cable Jacket Color

Status
Not open for further replies.
I sure hate to ruin a Forum trend and go back to the original question, but a lot old Romex I have seen that is white is not NM-B.
If I recall, the "B" designation came with the 90? requirement. I would suggest you confirm the cable you have is NM-B
 
augie47 said:
I sure hate to ruin a Forum trend and go back to the original question, but a lot old Romex I have seen that is white is not NM-B.
If I recall, the "B" designation came with the 90? requirement. I would suggest you confirm the cable you have is NM-B
Click to expand...

I believe if the nm is dated it is NM-B, not to say they didn't make NM-B prior to adding manufacture dates to the makring, just an easy spot.
 
augie47 said:
I sure hate to ruin a Forum trend and go back to the original question, but a lot old Romex I have seen that is white is not NM-B.
If I recall, the "B" designation came with the 90? requirement. I would suggest you confirm the cable you have is NM-B
Click to expand...


If it's 60 degree NM it is scrap metal IMO, white NM-B is what I call "bootleg wire". :D
 
mwm1752 said:
I believe if the nm is dated it is NM-B, not to say they didn't make NM-B prior to adding manufacture dates to the makring, just an easy spot.
Click to expand...

sorry confused... was there a 90? NM that was not marked NM-B ??
 
augie47 said:
sorry confused... was there a 90? NM that was not marked NM-B ??
Click to expand...
@Augie47 -

I believe the standard (UL 719) has always had a marking requirement. The 'B" was added to denote that the insulation values of the inner conductors are indeed equivalent to 90 Degree C values as you already know. When it was just Type NM, the inners did not permit taking advantage of the 90 Degree C for adjustment and corrections. The other issue was the wide spread use of luminaries that have component wiring that is rated 90 Degree C and due to the heat within the housing the transition of 60 Degree C to 90 Degree C caused an issue on some luminaries with higher wattages.

The actual inners of Type NM-B are not actually THHN/THWN-2 but they are permitted to be equivalent in design without a need for any wire marking designations so basically it is thermoplastic with nylon cover without any actual markings which is permitted by UL 719.

I have more history on the NM-B if you want it..but the above is the basic jist. The interesting thing about the color sheathing on Type NM Cable is that it started with Encore Wire when they introduced the first colored phase conductors. They figured lets mix some color on the Type NM PVC material and low and behold it came out rather nice....and it then was driven by NEMA to unofficially make it a color identifier that all of the NEMA Membership would adopt in their production.

In terms of the original question about the white Type NM Cable. I will assume you are referring to 12 AWG as white is choice of 14 AWG. If you get any 12 AWG with white sheathing it is perfectly fine....I would not worry too much about the date on it as long as it is truly 12/2 with G....the date is a requirement by UL as well as who made it and who was the QC that validated it but those requirements have been evolving for years as many of the manufacturers equipment now becomes multi-million dollar processes. I would worry more about where it was stored, was it outside in moisture and those other things that play havoc on non-metallic sheathed cable.
 
MasterTheNEC said:
@Augie47 -

I believe the standard (UL 719) has always had a marking requirement. The 'B" was added to denote that the insulation values of the inner conductors are indeed equivalent to 90 Degree C values as you already know. When it was just Type NM, the inners did not permit taking advantage of the 90 Degree C for adjustment and corrections. The other issue was the wide spread use of luminaries that have component wiring that is rated 90 Degree C and due to the heat within the housing the transition of 60 Degree C to 90 Degree C caused an issue on some luminaries with higher wattages.

The actual inners of Type NM-B are not actually THHN/THWN-2 but they are permitted to be equivalent in design without a need for any wire marking designations so basically it is thermoplastic with nylon cover without any actual markings which is permitted by UL 719.

I have more history on the NM-B if you want it..but the above is the basic jist. The interesting thing about the color sheathing on Type NM Cable is that it started with Encore Wire when they introduced the first colored phase conductors. They figured lets mix some color on the Type NM PVC material and low and behold it came out rather nice....and it then was driven by NEMA to unofficially make it a color identifier that all of the NEMA Membership would adopt in their production.

In terms of the original question about the white Type NM Cable. I will assume you are referring to 12 AWG as white is choice of 14 AWG. If you get any 12 AWG with white sheathing it is perfectly fine....I would not worry too much about the date on it as long as it is truly 12/2 with G....the date is a requirement by UL as well as who made it and who was the QC that validated it but those requirements have been evolving for years as many of the manufacturers equipment now becomes multi-million dollar processes. I would worry more about where it was stored, was it outside in moisture and those other things that play havoc on non-metallic sheathed cable.
Click to expand...

So -- A- when did they initially start the labeling Type NM-B, B-when was the color code started and C-when were manufacture dates added to the sheath marking"? My guesses are A- 1983 B- 1985 C- 1994
 
MasterTheNEC said:
@Augie47 -
Click to expand...

Paul, You may have answered and I'm just to dense to catch it......
If I come across some #12 Romex that is white and the jacket is not marked NM-B, is it possible that it might still be 90? conductors ?
 
Factual Tidbits.....Braid "Cloth" was still permitted until 1984. The sheathing of PVC Sheathing is rated 75 Degree C while the inners are rated at 90 Degree C...yet we can't exceed 60 Degree C per the NEC. Most manufacturers (I will not comment where i stand for obvious reasons) believe that the 75 Degree C would be sufficient for determining the ampacity value of Type NM-B Cable (excluding bundling and thermal insulation situations)...but the NEC rules (Unless you fine folks want to put in a public input *hint..hint)

In 1969, the reduced size EGC was removed by the UL Standard and NEC to require full size EGC's......on 14, 12 and 10 Type NM Cables.
 
augie47 said:
Paul, You may have answered and I'm just to dense to catch it......
If I come across some #12 Romex that is white and the jacket is not marked NM-B, is it possible that it might still be 90? conductors ?
Click to expand...
You are FAR from dense my friend.........and no I kinda did not answer because what we know is that the NM-B started in 1984 and Encore Wire has only been around since 1988 so I do not have that data....so only the "Other" manufacturers can answer that (my bail out answer)....but I can pull some old standards and see.

I would say this...if it is not officially marked Type NM-B then it is probably not because the way UL Standards work, when they come out with a change that at the time was critical to the wire and cable industry..everyone would have done it per the standard....so short anwser I would have is that if it is not marked Type NM-B...it is suspect.

Also...who is this Paul you speak of.....My name is Don Wilson:angel:
 
I might add this as well......when you look at some Type NM-B and the individual conductors versus an older Type NM, it will become clear which is 90 Degree C and which is not.....just in the constructon of the material in the PVC or lack there of. The best thing I can suggest is the following...

1) If it says Type NM-B on the cable....your are ok...if not proceed to # 2
2) Compare it with a known sample of Type NM-B Cable and notice the differences in the individual conductors insulation and see if that assists you.

At the end of the day.....if the cable does not have Type NM-B on the jacket....it is more than likely NOT.
 
mjf said:
It's fine..... as long as it's not so old that it has a reduced sized grounding conductor.
Click to expand...

It may not be acceptable if it was manufactured even as recent as pre 1986 it may have only thn/twn rated conductors which may not be allowed to wire a light fixture designed for 90* conductors.
 
I seem to remember a thread about a large residential contractor who had his NM wire made with a pink sheath and his co.'s name. This was an effort to stop thieves from striping new construction tract homes.
 
MasterTheNEC said:
I might add this as well......when you look at some Type NM-B and the individual conductors versus an older Type NM, it will become clear which is 90 Degree C and which is not.....just in the constructon of the material in the PVC or lack there of. The best thing I can suggest is the following...

1) If it says Type NM-B on the cable....your are ok...if not proceed to # 2
2) Compare it with a known sample of Type NM-B Cable and notice the differences in the individual conductors insulation and see if that assists you.

At the end of the day.....if the cable does not have Type NM-B on the jacket....it is more than likely NOT.
Click to expand...

Thanks, "Don"
(I normally associate names with faces but then again, the few times that we met.......
Don Wilson.jpg:D
 
mwm1752 said:
So -- A- when did they initially start the labeling Type NM-B, B-when was the color code started and C-when were manufacture dates added to the sheath marking"? My guesses are A- 1983 B- 1985 C- 1994
Click to expand...

B-1985 sounds like too early a date, I thought I remembered color coding starting in the '90s? Or had it already started and took a while to get to Georgia? Or am I just remembering wrong?
 
"B" has nothing to do with the jacket color. NM-B=90C conductors. NM without the B=60C conductors.

I believe they started color coding the jacket in the early 2000's.
 
ceb58 said:
I seem to remember a thread about a large residential contractor who had his NM wire made with a pink sheath and his co.'s name. This was an effort to stop thieves from striping new construction tract homes.
Click to expand...
I can tell you that anything may be possible...but in order for a manufacturer to do that for a contractor they would have to purchase a HUGE amount of cable.......I know we would not do it unless the purchase was for hundreds of thousands of feet and even then it would be rare since we do not sell directly to contractors.....so that level of customized construction would be from a small outfit.
 
Status
Not open for further replies.
Top