One thing to look at is the actual line voltage into the house.208 volts comes from wiring across two phases of 120v 3-phase service, which is only found in commercial buildings or larger apartment/condo buildings.
You might only have 208v service. It is unusual to see such voltage but it is out there.
Of course one should never attempt to power electronics in this fashion. But for a dedicated 120v line, the wiring practices are equivalent (electrically) to residential "split phase" 240v service.