From your description I picture that the contractor skinned part of one of the grounding conductors and fed it through a lug (wire uncut) that was attached to the inside of the trough. I like your thinking, and I think I understand what you are asking. After looking through Articles 200, 230, and 250, I can find no code to accomplish what you seek.
Looking at 310 like you say, specific to parallel conductors, I am leaning toward agreeing with you. I think the intent of the code is that all parallel conductors be treated in exactly the same manner. That being said, bonding only one of them to the gutter (trough) may have some sort of weird effect given a fault condition -- although I don't know what. I also believe we are not all-knowing and there is no way we could know that.
So yes, you can use that code to have the contractor treat all the parallel service conductors in exactly the same manner. I don't necessarily believe that the conductor is being "terminated" at the trough, but it is being bonded to the trough, and thus grounding the trough itself. So the contractor should treat all of the parallel conductors in the same manner. Or -- run a single tail from the polaris tap and be done with it.
Good question. It is not everyday that someone makes me think. Anyone else agree or disagree? Please chime in.
Edited by Nick Sasso (08/03/11 05:48 PM)
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