The largest residential service that I ever did was a 1,200 amp single phase that required actual switch gear in the basement. Everything from that point was 42 ckt. 200 amp sub panels located throughout the 12,000 SF mansion. I was surprised that we didn't do a three-phase service, but my guess is that the POCO couldn't get it to us at this location in a rural part of northern New Jersey. Even the ten-car garage and the 16-stall horse barn each had their own 400 amp services. Talk about a learning experience. PSE&G was happy to give us all the single-phase power we wanted. I guess they were looking at many years with all of those spinning meters.
