Good find, thanks.Page 3 of the manual - 220 V, 30 Amp supply to get the rated output of the Epic 1600.
Never seen one before in my life.I don't know how common this type of connector is across the pond, but here in the UK, they're known as BS4343/IEC 60309 plugs and sockets. Yellow for 110 V centre-tapped isolation supplies for power tools etc., blue for 240 V single phase and red for 415 V 3-phase.
For better or worse, our standard AC supply is 115v using IEC type connections on the gear.
Armchair quartbacks