Romex with insulated EGC?

Status
Not open for further replies.
J

JFletcher

Senior Member
Location
Williamsburg, VA
Was doing some wiring in a trailer yesterday and came across Romex with an insulated ground wire. The jacket reeds " General Cable 14/2 with ground type NM Romex TJ 600 volt".

It looks like normal modern Romex except for the insulated ground wire and the pull string is different. There is no paper in the jacket.

it appears to be factory wiring however the trailer was built in 1969. Was Romex made this way back then? If so it seems Superior to modern-day Romex that has an uninsulated ground and paper in the jacket

The ground wire is full size i e 14 gauge. all three wires are in one jacket and not separated like UF cable would be.
 
I believe they had Romex back then. They definitely had nonmetallic cable. They've had nonmetallic cable since the beginning of the 20th century. I wouldn't say that older Romex is superior as there have been many advancements in insulation polymers since then.

Sent from my A574BL using Tapatalk
 
JFletcher said:
Was doing some wiring in a trailer yesterday and came across Romex with an insulated ground wire. The jacket reeds " General Cable 14/2 with ground type NM Romex TJ 600 volt".

It looks like normal modern Romex except for the insulated ground wire and the pull string is different. There is no paper in the jacket.

it appears to be factory wiring however the trailer was built in 1969. Was Romex made this way back then? If so it seems Superior to modern-day Romex that has an uninsulated ground and paper in the jacket

The ground wire is full size i e 14 gauge. all three wires are in one jacket and not separated like UF cable would be.
Click to expand...

I was apprenticing during the summer of 1969, and I helped with new construction roughins. Some of the NM cable I installed back then had green insulated EGCs, some NM didn't. It was a manufacturer's choice.

Personally, I feel it adds additional installation time to have to strip out the EGC.

It makes economic sense to me that EGC insulation in NM didn't last very long.
 
I think I have seen full size insulated EGC a time or two, but most insulated EGC's I have seen in NM cable were back when they only had a 16 AWG EGC in a cable that had 12 AWG current carrying conductors. It wasn't ordinarily "round" either it sort of was formed to fit between the other conductors.
 
al hildenbrand said:
JFletcher said:
Was doing some wiring in a trailer yesterday and came across Romex with an insulated ground wire. The jacket reeds " General Cable 14/2 with ground type NM Romex TJ 600 volt".

It looks like normal modern Romex except for the insulated ground wire and the pull string is different. There is no paper in the jacket.

it appears to be factory wiring however the trailer was built in 1969. Was Romex made this way back then? If so it seems Superior to modern-day Romex that has an uninsulated ground and paper in the jacket

The ground wire is full size i e 14 gauge. all three wires are in one jacket and not separated like UF cable would be.
Click to expand...

Have definitely seen that same brand and style of cable many times------except IME, the insulated egc is undersized.

Little nugget: the NM you saw had to have been fresh out of the factory as the full size egc was mandated for NM in '69 FWIU.
Click to expand...
 
DrSparks said:
I believe they had Romex back then.
Click to expand...

The Rome Wire Company, of Rome, New York, is credited with the invention of Nonmetallic Sheathed Cable in 1922. This first NM was marketed by Rome Wire Company under the name "Romex".

NM was first described in the NEC in 1926.

"Romex" is now a trademarked brand of the Southwire Company.

"Romex" is used in loose jargon as the "name" for any NM cable, much like Milwaukee Electric Tool's "Sawzall" became the name of common parlance for most any reciprocating hand-held power saw.
 
user 100 said:
Have definitely seen that same brand and style of cable many times------except IME, the insulated egc is undersized.

Little nugget: the NM you saw had to have been fresh out of the factory as the full size egc was mandated for NM in '69 FWIU.
Click to expand...
Yes. The 1968 NEC mandated the EGC then be full sized, and was going into enforcement, depending upon local adoption by the local AHJ.

The first summer of my apprenticing (while I was home from my EE studies) was 1968 and the reduced gauge EGC was all that was available, and SOME of that NM that I installed had thin green insulation on the EGC, some EGCs were bare. The choice for the green insulation was entirely a design feature of the cable manufacturer.
 
Last edited:
al hildenbrand said:
Personally, I feel it adds additional installation time to have to strip out the EGC.

It makes economic sense to me that EGC insulation in NM didn't last very long.
Click to expand...

X2- adds labor, no real need for it.

This comes up every once in a blue moon with one argument being that the insulated egc is immune from faulting out if it happens to hit a hot.

Ofc, another reason we can't have it will be a little harder to justify nms dry loc only for certain things......UF cost more.;)
 
Thank you all for the replies and information it's been a good learning experience and very helpful. About the insulated ground taking more time to strip out sure it takes a little more time, however with most circuits now requiring arc fault and or ground fault protection having an insulated ground wire May prevent some faults that would normally happen.

I forgot to mention this is all copper wire but I assumed most of y'all would know it was copper since I didn't mention aluminum specifically.

And yes since the ground is insulated and there's no paper you could probably use this as UF cable even though it would be against code.
 
JFletcher said:
I forgot to mention this is all copper wire but I assumed most of y'all would know it was copper since I didn't mention aluminum specifically.
Click to expand...
FWIW, which probably isn't a lot, I have no first hand experience with small gauge NM Aluminum that had insulated EGC. I did handle a fair amount of it. . . just never ran into the insulated EGC, if it existed.

Edit to add: And by small gauge, I mean #12 and #10
 
JFletcher said:
Was doing some wiring in a trailer yesterday and came across Romex with an insulated ground wire. The jacket reeds " General Cable 14/2 with ground type NM Romex TJ 600 volt".

It looks like normal modern Romex except for the insulated ground wire and the pull string is different. There is no paper in the jacket.

it appears to be factory wiring however the trailer was built in 1969. Was Romex made this way back then? If so it seems Superior to modern-day Romex that has an uninsulated ground and paper in the jacket

The ground wire is full size i e 14 gauge. all three wires are in one jacket and not separated like UF cable would be.
Click to expand...
What is the "pull string".
 
ptonsparky said:
IIRC some had a jacket that could be ripped with the pull string. I was never tough enough to use it and my Klien lineman knife was just too easy to use.
Click to expand...

Yeah that was the idea I think. My wire strippers have a built-in 12 and 14 2 NM stripper anyway so I would never use the included pull string. Now for Comm cable it's totally different story, I use that all the time, it's faster and safer than trying to cut the jacket any other way, which can damage the pairs of cable.
 
Status
Not open for further replies.
Top