Thanks for the contribution guys. Other than learning about a couple of small points myself, seems like all are agreeing that the isolation transformers resolve the question at hand. All the plans have been stamped and DSA as well as other pertinent AHJs have approved the drawings + bids have been submitted and close to being fully processed. I guess what "the guy" thinks at this point is irrelavant, but, unlike some engineers, I do care about treating the clients (and their representatives) with respect. I very much wished he would understand the issue, but I think I've put forth more than enough effort in this case and will respectfully let him know that we're done talking about this. Thanks again for all your input.
