I know this is common knowledge now, but just for people who might not realize it: a typical North American NEMA 5-15R receptacle will indeed deliver 120V 15A electricity, but the electrical grid is split-phase 240V. Right across from my dish washer is an electric range; most of these require 240V 30A or 50A receptacles (I think mine is 30A, but I could be mis-remembering.) So it's not like we couldn't have higher power dishwasher, but if you already have central water heating it's kind of senseless to heat the water at the dishwasher.
> electrical grid is split-phase 240V
The electric grid is three phase; 60 or 50 hz depending on where you are in the world. The voltage varies considerably, long distance transmission is in the kilovolts, or higher.
"split-phase 240V" happens at the transformer near your house, in North America. I don't know as much about the rest of the world, but I've always understood it to be ~440v split phase because it allows longer wires between the transformer and the house.
Yes of course, but obviously when it comes to household dishwashers those parts of the grid are not terribly important and I think we already exceeded the pedantry budget enough.
> "split-phase 240V" happens at the transformer near your house, in North America. I don't know as much about the rest of the world, but I've always understood it to be ~440v split phase because it allows longer wires between the transformer and the house.
Where I live, we have three phase 480/277V for commercial. I believe that is standard in North America, but I'm not really sure.
One of the reasons for the NACS switch is because light poles are ~270 volts, and NACS supports that voltage.