ECN Forum
Posted By: JoeRossi Wire color of Type NM - 09/15/07 03:11 PM
Now a day when you buy Type NM #14AWG is white, #12 is yellow, etc. Who made that standard and why. Would love to know. Thanks
Joe
Posted By: HotLine1 Re: Wire color of Type NM - 09/15/07 03:32 PM
Joe:
I'm not sure, but I think it's a mfg move. It's a help for us inspectors, and I think some of the EC's like it also.

"Go get the 'yellow' roll"....mech to new helper, as opposed to "read the numbers 12-2" perhaps
Posted By: Rewired Re: Wire color of Type NM - 09/15/07 05:07 PM
I have to agree with John.. As far as I know it was so the inspectors could easily identify circuits that are "different" in new construction, as in Blue NM for the arc fault circuits and yellow for the 20A kitchen circuits. Also according to one inspector I talked to and almost got dinged for was to identify voltage! Anything with a red covering contains red and black conductors and is "supposed" to be 240V, no neutral, and explained that its to prevent anyone from thinking the "white is neutral" when in fact it is not such as if you used a regular piece of 2 conductor N.M with black and white conductors on a 240V circuit. That is where I almost got dinged but the inspector "let it go this time" and laughed a bit while saying so!
Years ago I can remember they had plastic sheathed NM in 3-4 colours and even way before that in the days of paper wrapped "loomex" they had what 7 colours that I can think of off the top of my head that were used throughout the years but I think it was only a manufacturing thing back then, the sheath colour meant nothing.

Personally I like the idea of colour coding the cable for the obvious reasons, but it also helps me identify what coils of what cable I have in my van at any given time!

A.D
Posted By: Theelectrikid Re: Wire color of Type NM - 09/15/07 05:09 PM
It also helps when you're getting wire cut by the non-English speaking immigrants that work at Home Depot. (At least at mine.)

Ian A.
Posted By: renosteinke Re: Wire color of Type NM - 09/15/07 07:47 PM
Around 1998, Rex Cauldwell wrote an article for "Fine Homebuilding" magazine about wiring techniques with Romex. As a side note, he showed how he used spray paint to mark the edges on new rolls of Romex, to help his guys grab the right roll from the truck the FIRST time.

Maybe two years later, one cable maker (I think it was Southwire) began to distribute the colored stuff. Other makers quickly followed.

AFAIK, this was a purely voluntary move by the makers, without any code or industry standard to encourage it. I also suspect that there may be some economies involved; adding color makes it easier for the maker to mix in recycled materials.
Posted By: Tom H Re: Wire color of Type NM - 09/15/07 11:32 PM
Someone told me once that when they made that standars change, that blue was going to be the color of 14-2, I think I even remember seeing that at a trade show once. Obviously that did not happen, but it would be interesting to hear the manufactures perspective on this question
Posted By: NORCAL Re: Wire color of Type NM - 09/16/07 01:50 AM
Just think about some of the ones pulling it, if they were laying sod the crew leader would be yelling "Green side up,green side up".
Posted By: Sandro Re: Wire color of Type NM - 09/16/07 02:27 PM
Now if only they could come up with colour coded armoured (BX) cable.

Posted By: electure Re: Wire color of Type NM - 09/16/07 03:30 PM
Sandro,
Do you mean like THIS?

AFC's color coded MC and AC cable has been around since before the color coded NM cable
Posted By: pauluk Re: Wire color of Type NM - 09/19/07 04:11 PM
Our equivalent of NM in Britain isn't so colorful.

The old 1950s/60s Imperial-size cables were a case of "you can have any outer sheath color you like so long as it's gray."

I'm not exactly sure when it first appeared, but sometime after the switch to metric sizes in the 1970s manufacturers started offering white sheaths as well. They became quite common during the 1980s, especially for exposed surface runs. The clips were then made in both gray and white versions.

With the recent change to the new European color coding for the internal conductor insulation, the cables are back to being available only with a gray sheath.
Posted By: HotLine1 Re: Wire color of Type NM - 09/20/07 11:17 AM
Paul:
Reminds me of a client who wanted to know what colors PVC conduit was available in! I said 'gray'; she said what shade? Needless to say...she hired a painter; two attempts later...she had 'federal blue' PVC to blend in with the architecture.

Take care
Posted By: Mike Wescoatt Re: Wire color of Type NM - 09/20/07 01:41 PM
Around here I've seen only white 14GA, yellow 12GA, orange 10GA, and black (in 8GA or larger... might be type SE). Are there other colors now?
Posted By: gfretwell Re: Wire color of Type NM - 09/20/07 04:37 PM
John
I used EMT to put in all the lights around my pool. (18 H101s and 5 motion sensors) My screen cage is bronze (dark brown) so I had to paint it all. I ended up bending all the pipe. Putting it up to be sure it all fit, then taking it down and shooting it and putting it back up. It was a PITA but the result was worth it.
Posted By: pauluk Re: Wire color of Type NM - 09/22/07 09:08 AM
Originally Posted by HotLine1
Reminds me of a client who wanted to know what colors PVC conduit was available in! I said 'gray'


We have black and white over here:

http://www.tlc-direct.co.uk/Main_Index/Conduit_Pvc_Index/index.html
Posted By: e57 Re: Wire color of Type NM - 09/22/07 05:23 PM
Originally Posted by Rewired
Blue NM for the arc fault circuits and yellow for the 20A kitchen circuits.


Blue????

Anyway, I thought this was a NECA thing with the colors - and they got the manufacturers to comply with thier whims.

A supply house I go to had an enormous amount of NM stock piled that took them 4 YEARS to get rid of. And for a while after they changed the color to yellow on #12 you would need to point out to the inspectors that it was #12 - just several years old.
Posted By: sudsy4 Re: Wire color of Type NM - 09/25/07 01:27 AM
I do rememer light blue NM long time ago
Posted By: gfretwell Re: Wire color of Type NM - 09/25/07 02:45 AM
There was a lot of blue NM in the early 80s. I am not sure who was making it. I also saw dark brown NM in the same time period.
Posted By: NORCAL Re: Wire color of Type NM - 09/25/07 03:25 AM
In late 1960s Phelps-Dodge made a blue colored NM cable. Building I saw it in was built 1968.
Posted By: EV607797 Re: Wire color of Type NM - 09/25/07 02:50 PM
We used the light blue Phelps-Dodge blue cable well into the late 1970's in new work. A lot of their cable was also black. What was odd was that in many cases, the black conductor was actually brown. I don't know if this was intentional or just a case of someone not mixing enough dye into the batch.

We also used a lot of cable made by Cadillac Cable that had a green or brown jacket.

I'd say that it's safe to guess that it was just a case of manufacturers wanting their product to be more identifiable.
Posted By: gfretwell Re: Wire color of Type NM - 09/25/07 05:06 PM
I turned up some unusual NM in my house, probably installed in the late 70s, early 80s. It actually had color coded copper. The white wire had a silver cast to it and the black was a deep bronze color.
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