Originally Posted By: jmyers This post was automatically imported from our archived forum.
I have a wire question for all of you.
Came across some NM-B cable (8-3 w/g) the other day. It was #8 wire but the insulated conductors were marked one, two and three. Anyone ever seen this before?
I have to say, that in my many years working with electricity, I have never seen cable marked like this. Anyone know if this is a new thing? Wire from the big orange? New stupidity wire for challenged electricians?
What made this wire fairly unique was that all four conductors had black insulation (thermoplastic). Is what I thought was really strange was that two of those wires have to be color specific, white/gray for the neutral and green or bare for the ground.
Originally Posted By: jmyers This post was automatically imported from our archived forum.
Bob,
Yep, I am certain it was NM-B cable. I was thinking that someone picked it up from like the big orange and did it themself.
While I just deleted the pictures, it clearly showed two of the four black wires running to a 2 pole 100 amp breaker. The other two black wires were running to the neutral/grounding bar.
I was able to manipulate the cable enough to see in the words 8/3 wg but I was not able to see the words NM-B, although it looked like ordinary sheathed cable, just like any other NM-B that I have seen.
Originally Posted By: jmyers This post was automatically imported from our archived forum.
William,
I can say with a fair amount of certainty, this was NM-B cable.
Do you know something about three phase services that I don't? Why I say that is that I don't come across three phase services much, if at all, and I have never heard of any cable, in particular NM-B cable that was specifically manufactured for three phase services. That is not to say that 4 and 5 wire cables are not made, I know they are, just that they are not specific to three phase services. Anyway, this was a three wire cable with ground, with three phase you would need a four wire with ground and the neutral would still have to be white or gray and the ground would have to be bare or green.
Originally Posted By: wrobedeau This post was automatically imported from our archived forum.
There are several types of 3 phase service. A Y service which is 4 wire with ground. A delta service is 3 wire with a ground and a grounded B phase which is three wire. While I am not a Sparky I have seen all 3. Three wires with a ground will work on a delta or grounded B Phase. Try these links.
Originally Posted By: wrobedeau This post was automatically imported from our archived forum.
The wire could be used on a 3 phase branch circuit wire on any delta or grounded “B” phase 3 phase system.
The circuit combinations and arrangements are quite extensive depending on whether you are using it for lighting, electrical heating or inductive loads. Recommend you research wiring diagrams for 3 phase branch circuits. Try lighting and electrical heating contractors or your local library.
Originally Posted By: jmyers This post was automatically imported from our archived forum.
William,
I went a step better and checked with american wire and I could not find any such wire in their catalog. I certainly understand what you are saying about the three phase services.
I worked for an electrical distributor for 5 years and in those five years I never saw any wire that was configured with all black insulation on all the wires.
Never have I seen 8-3 wire with all the conductors with black insulation. Is what was even stranger, was the fact that it was NM-B cable.