Routed together

[Timbert]

I'm reviewing a set of plans that involves receptacles which are mounted on the far side of a flexible cable carrier (cable chain/wrap).

The design currently features a cable with 4 conductors (three phases and earth ground) alongside a single conductor (neutral).

My code-fu is weak.

I believe the applicable article is 300.3(B). If all conductors are in the same raceway or cable tray, but not in the same cable, is that permitted? Is there another section of the code that is applicable?

 

[Volta]

That's a tough one. I believe the intent of that list given in 300.3(B) is meant to restrict the conductors to be included in the smallest unit used: within the jacket of a cable if that is what is used, within the same raceway, within the same trench, etc.

With that interpretation, I would suggest that it would not be allowed to have 3 of the 4 circuit conductors grouped, while the fourth is not.

I think that is further supported by sub-section (B)(2), wherein grounding conductors are occasionally permitted outside the bundle, but grounded/neutral conductors are not.

Now, some relief may be found in 300.3(B)(3), but to meet the language precisely, the neutral would have to also be in a cable, not simply an open conductor, and of course both sheaths would have to be non-ferrous.

Then where the neutral rejoins the other conductors, the receptacle enclosures would have to be non-ferrous, or slots would need to be cut between the entries. 300.20(B).