Greg It's actually a medical center. I just had a quick chance to look at the situation today. Monday I am going to look for the obvious: rooftop equipment, fans etc. I'll be spending a few hours educating myself over the weekend. I doubt I'll be confident enough to start grounding phases with resistors though:)I visualize some little old lady with a cane chasing me down the hallway because the power went off!I love these jobs where you get to learn something new!