[DonRotolo]

I can offer some feedback from MAR events:

Often a gym or cafeteria has 2 or 3 20A circuits, intended for floor maintenance equipment and such, and this is generally inadequate for pits.

MAR rents a several kW 3-phase generator and owns a distribution system (cables and boxes) used to deliver 120 VAC to the pits. As a single data point, I saw each phase was drawing about 30A during the middle of the Mt Olive competition (about 42 teams). I don't know the generator size but guess at 20 kW or so - a trailer with a generator 5' tall, 8' long and 5' wide or so.

I have seen this same setup at other MAR events.

For offseason events, I have seen events get by with extension cords from nearby electrcial circuits, maybe 6 circuits total for 32 teams, and 3 circuits for 20 teams (IIRC).

I can have Ed Petrillo of MAR contact you, he has more precise details and some of the design calculation considerations in mind. PM me if you need his e-mail address.