Most common commercial service voltage in the area of the US I work is 480 phase to phase 277 to ground, transformers used to get it down to 208/120 so we end up with 4 voltages in most commercial spaces.
Small commercial service about 600 amps, a typical grocery we wire 1600 amp, and larger office buildings 3000 amp.
Bob Badger Construction & Maintenance Electrician Massachusetts
