Thanks for all your input. To answer Bob's first question, and as addressed in other posts, this concept seems repulsive to me from a workmanship point of view, the possibility for errors by installers and/or future workers is just too great and very dificult to troubleshoot. I and another foreman once spend a few days in a new highrise in LA tracking down and correcting a half dozen or so crossed neutrals in exit lights (emer & norm). I can't tell you how much fun that was!
Without being specific concerning location, the two panels in this case are far enough apart that they are most probably on different meters, although the same customer and same utility. I'm thinking they're about a mile apart. Voltages are the same, but different utility meters.
The reason for the alternating panel circuits in the first place is that's what is indicated in our preliminary (as-bid) design. We do this so that in the event that an entire auxiliary power station bites the big one, we don't loose all the lighting. Every other light is still powered from the neighboring power station. Again, I am avoiding specific locations here.
I believe the main reason for considering the single conduit is to economize; minimize costs on a firm fixed price design / build contract. After all, a single conduit is less expensive to provide and install than two are, even if it is a size bigger.
Thanks again for the great responses,
Radar
