New NM Cable ??

Status
Not open for further replies.
Bill Annett

Bill Annett

Senior Member
Location
Wheeling, WV
Occupation
Retired ( 2020 ) City Electrical inspector
I have not bought any NM cable for a while but I was told that the NM cable now has an insulated green ground conductor. Is that true and if it is true, who makes it? I personally think that it would be nice to have an insulated ground conductor. Once I get home, I will go on line to see what I can find out.

Thanks, Bill
 
Have not heard of a requirement for that. But my house that was rewired in the (I think) early 80's has some NM cable with a green insulated grounding conductor. This also has a smaller sized EGC (looks like #16 when the other two conductors are #14).

So it has been available in the past.
 
suemarkp said:
Have not heard of a requirement for that. But my house that was rewired in the (I think) early 80's has some NM cable with a green insulated grounding conductor. This also has a smaller sized EGC (looks like #16 when the other two conductors are #14).

So it has been available in the past.
Click to expand...

That would be some really weird cable, also a full sized EGC for small branch circuits has been required since 1971 IIRC.
 
I don't know when the remodel happened, but there was the old silver cloth cable, newer black plastic NM with the green insulated ground (both those two had smaller EGC's), then normal white NM and finally the NM-B I added with white, yellow, or orange jackets. House was built in the 60's, so I'm sure cables were installed at various times.
 
suemarkp said:
I don't know when the remodel happened, but there was the old silver cloth cable, newer black plastic NM with the green insulated ground (both those two had smaller EGC's), then normal white NM and finally the NM-B I added with white, yellow, or orange jackets. House was built in the 60's, so I'm sure cables were installed at various times.
Click to expand...

It is always interesting to me to run across the various types of of old wiring.
 
jumper said:
That would be some really weird cable, also a full sized EGC for small branch circuits has been required since 1971 IIRC.
Click to expand...


The ones I have seen with an insulated equipment grounding conductor did not have a full sized equipment grounding conductor.
 
Ran across an addition that was wired with what looked like #12 stranded NM cable that contained a green insulated ground. Turned out to be a cable that was manufactured for RV's.
 
Thanks for all of the information. I went on line, and I too could not find any new NM with an insulated ground.


Thanks Again, Bill
 
suemarkp said:
Have not heard of a requirement for that. But my house that was rewired in the (I think) early 80's has some NM cable with a green insulated grounding conductor. This also has a smaller sized EGC (looks like #16 when the other two conductors are #14).

So it has been available in the past.
Click to expand...
I'm pretty sure the reduced size EGC was not allowed by 1980's, all I have ever seen with reduced size EGC (10AWG and smaller anyway) I would guess was 1950's maybe into 1960's installations.

jumper said:
That would be some really weird cable, also a full sized EGC for small branch circuits has been required since 1971 IIRC.
Click to expand...
That date corresponds to what installations I can recall seeing using smaller EGC.

Dennis Alwon said:
The ones I have seen with an insulated equipment grounding conductor did not have a full sized equipment grounding conductor.
Click to expand...
Same here, and was pre 1970's installations as well.
 
Looks like the elusive "NM-C" has been found - under the guise of 'marine wire!'

While the link is silent as to any listings .... well, it does make you wonder.

Not a "Chapter 3 method?" Well, if not- it should be!
 
Thank you, Gold digger!

A little more digging came up with this manufacturer link: http://www.northwire.com/industries/647/products/ul-1426-electrical-cables-for-boats .

From this manufacturer, it appears that their specific cable MIGHT also be listed for use as building wire. personally, I see no reason to reject this wire, and it's a clear case of when the AHJ should exercise his authority to depart from the strict text of the NEC.

(Of course, I personally also favor anything that will give a future HI an attack of the vapors :D )
 
renosteinke said:
Looks like the elusive "NM-C" has been found - under the guise of 'marine wire!'

While the link is silent as to any listings .... well, it does make you wonder.

Not a "Chapter 3 method?" Well, if not- it should be!
Click to expand...



renosteinke said:
Thank you, Gold digger!

A little more digging came up with this manufacturer link: http://www.northwire.com/industries/647/products/ul-1426-electrical-cables-for-boats .

From this manufacturer, it appears that their specific cable MIGHT also be listed for use as building wire. personally, I see no reason to reject this wire, and it's a clear case of when the AHJ should exercise his authority to depart from the strict text of the NEC.

(Of course, I personally also favor anything that will give a future HI an attack of the vapors :D )
Click to expand...

The specs say it's fine stranded. That's great for pulling but a real PITA to terminate or splice. That's possibly the reason it would not be considered for Chapter 3 as premises wiring.
 
K8MHZ said:
The specs say it's fine stranded. That's great for pulling but a real PITA to terminate or splice. That's possibly the reason it would not be considered for Chapter 3 as premises wiring.
Click to expand...
I use stranded conductor all the time for premises wiring, just not with type NM cable, but if NM cable were readily available with stranded conductors in 14-10 AWG I may consider using it. 14 AWG I may prefer solid, but 12 AWG is worth consideration, and I think I would prefer 10 AWG to be stranded in most all cases, just is easier to work with in general. I never buy 10 solid THHN/THWN, it is always stranded, 14 and 12 I mostly use stranded, but do have occasions where solid is preferred, but those seem to be getting to be less preferred locations as time goes by.
 
kwired said:
I use stranded conductor all the time for premises wiring, just not with type NM cable, but if NM cable were readily available with stranded conductors in 14-10 AWG I may consider using it. 14 AWG I may prefer solid, but 12 AWG is worth consideration, and I think I would prefer 10 AWG to be stranded in most all cases, just is easier to work with in general. I never buy 10 solid THHN/THWN, it is always stranded, 14 and 12 I mostly use stranded, but do have occasions where solid is preferred, but those seem to be getting to be less preferred locations as time goes by.
Click to expand...

But this stuff is fine stranded, not just stranded. I have worked with fine stranded wire and I could see where terminals and connectors would not be listed for use with it. Using wire nuts on fine stranded wire usually results in one or more of the strands actually being cut by the metal threads in the nuts.

There is also a chance that breaker terminals won't tighten down all the way on fine stranded wire.
 
Status
Not open for further replies.
Top