SKM cable types - IEEE Redbook

[ChadElectrical]

First post! I have been reading a lot on here, but it's finally time to join. Question below.

I have what seems to be a very basic question but cannot find a solid answer anywhere for it. In SKM Power Tools on the low voltage cable library, many of the entries come from the IEEE 141 - Redbook. One thing that is not very clear to me is the different between a few of the conductor descriptions. For instance, 3/C+G vs 3-1/C+G. I would assume 3/C+G is 3 conductor plus ground, 3-1/C+G is 3 conductor, plus neutral, plus ground. This all makes sense until I saw 4/C+G and 4-1/C+G. 4/C+G seems to imply 3 conductor plus neutral plus ground, but what does 4-1/C+G mean? Double ground? Two Neutrals?

The change in impedance per foot is fairly small but there is a difference between say 3-1/C+G and 4/C+G. Over a longer distance, I think that difference will affect the overall SCC calculation.

Can anyone clarify the differences?

I appreciate any insight. Thanks!

-Chad

 

[davidbeach]

3/C is a single 3 conductor cable. 3-1/C is three single conductor cables.

 

[DaveMeharg]

I also agree with David. 3/C +G is a cable that consist of three inculated conductors and a ground in an overall jacketed assembly. 3-1/C +G are three seperate insulated condcutors with a ground. The 3/C cable assembly is tightly constructed so it typically would have a lower AC impedance then 3-1/C +G. I hope that clarifies it a bit.