Somewhere along the way, I decided to stick with 120vac/240vac, because its more symmetrical.
I've been confused on the 220/240 voltages for decades.
I've heard people say they have 220v coming into the house, and 120v at the outlets.
To me, that never made any sense. It has to be 240v coming into the house or 110v at the outlets.
Because at our house, 2 legs of 120 volts (phase shifted) come into the house. One leg goes to the lights, the other leg goes to the outlets. The 240 volts for the Air Conditioner and the clothes dryer is bridged in between the two 120 volt lines.
Logically, the power coming into the house has to be called 240 volts, because it comes from 2 x 120 volt lines.
BTW - It would be insane to wire a wall outlet with the leg thats used for the lights. It would be phase shifted from the other wall outlets, and that could be very bad. The house has basically two, parallel circuits that are out of phase.
I just learned that the 420v, 440v and 480v are different.
I wasn't aware of that. I think now, I'm more confused than ever about the whole thing.
I suppose it might not have made much difference to me when I was working with Air Conditioning. I always trusted the installer to get that part right. We always changed out bad parts.