Dual Source Feeds

[Dave Genson]

I would like to input two separate 300 Amp sources of power into a single 24 x 18 x 6 J-Box for distribution to two separate remote power panels. Is this permissable by code?

 

[steve66]

I don't know if your Jbox is sized large enough, but there is nothing to prevent two sources in one box (unless one is an emergency source).

Steve

 

[Dave Genson]

Thanks ~ Does the NEC reference this at all?

 

[steve66]

I don't think the NEC directly addresses this (again, for other than emergency systems). The general rule is that if the NEC doesn't prohibit something, then it is allowed (as long as you are not violating the UL listing of a item). And, of course, there may be other codes or OSHA regulations that might address this, but as far as I know, its allowed.

Some people may feel that mixing power from two sources in a single box is a bad design since an electrician may only turn off one source before working in the box. But in this case, with (2) 300A feeds, it seems like it would be obvious that there are two sources.

Steve

 

[infinity]

I agree with Steve. The box may be a little small depending on the size and entries of your conduits.

 

[LarryFine]

. . . it seems like it would be obvious that there are two sources.

Unless someone assumed them to be fed in parallel, but then, anyone qualified to work on this equipment should be aware and know how to check.

We are talking about two isolated feeders simply sharing a raceway, right?

 

[steve66]

With 300A, I assumed they were in separate raceways.

At any rate, it never hurts to put a label on the box: "Caution: 2 sources of power".


Steve