The other day I came across some NM-B cable, 8-3 w/g, which had wires which all had black insulation and were numbered one, two and three.

Is what struck me as odd, was that the insulation on all the wires was black, no white/gray for the neutral and bare/green for the grounding wire.

While I could not manipulate the wire enough to read the words NM-B, I could read the words 8-3 w/g and the outer coverings were consistent with sheathed cable.

Has anyone ever seen this before, or know anything about the source of the wire?

Thanks,

Joe Myers

Sounds like you have some "tray cable" to me.
Don

Found this for you thought you be interested!
http://www.faqs.org/faqs/electrical-wiring/part2/section-5.html

I think it may be tray cable, too.
http://www.houwire.com/catalog/technical/color_code.asp
ICEA/NEMA Method 4 – A neutral- or single-colored insulation compound is surface ink printed with conductor number to provide positive conductor identification through 21 conductors.

Aside — 99 NEC 200-6(e) and 250-119(c) seem to correspond with the multiconductor-cable “no white or green” individual-conductor coding to be field-reidentified as grounded and grounding conductors… with the usual disclaimer ”where conditions of maintenance and supervision ensure that only qualified persons will service…”

Thank you everyone, I appreciate the help. I have never run across any tray cable before, so it looks like that may be my answer.

Has anyone ever seen or heard of this stuff in a number 8 stranded?

Second question. Is the sheathing on tray cable like that of NM-B cable?

Joe Myers

Joe,
Tray cable comes in all sizes from #18 or smaller to 500kcmil and larger. It can have 2 to more than 50 conductors. It comes with or without grounding conductors. Some is color coded and other is numbered on all black conductors. Most of it that I have seen has a black outer jacket and a very close resemblance to NM.
Don

[This message has been edited by resqcapt19 (edited 03-18-2004).]

Type TC typicals.. http://www.houwire.com/catalog/products.asp?catid=45 http://www.houwire.com/catalog/products.asp?catid=46
N.B.: “Color Code: Power Sizes: ICEA Method 4”

[One rare occasions, TC may be found 'fished' into walls.]

Don,

Thanks for the reply. I have never seem cable tray before, so this is a new one on me. Is this stuff pretty common? Meaning, do you use it, or see it a lot?

BJarney,

Thanks for the links. I had read previously after it was suggested this maybe tray cable, that this stuff is suitable for direct buriel, now I am sure that it is. That would make good sense since this was servicing a sub panel in a detached garage and I could not verify it was running in conduit to the garage.

Thanks,

Joe Myers

Joe,
It is a very common industrial wiring method.
Don

I've used tray cable many times for temp. repairs in the winter when it would be impossible to pull new wires up here in the cold cruel north otherwise known as Maine . 7 or 9 conductor tray cable, wire tied to a cable, strung from the building to the gas pump canopy, down the canopy pole, out across the island in a pipe, in the side of the dispenser and up comes the pump again . The state of Maine is pretty lenient on temp. fixes

I love tray cable.
We even nicknamed it "industrial romex".
It's very easy to work with.
The cost is not much more than you'd pay for individual stranded conductors.