Even with individual breakers, why would they need to be less then 15 amps? Nothing would need OCPDs any less. You couldn't use smaller than AWG 14 on any of the wiring.
I'm thinking about data centers ranging in size from 24 to 1200 rack cabinets, with 18 to 108 computers per cabinet (and lots and lots of air conditioning). Maybe ONE 240 volt 20 amp circuit would be enough per rack.
I'm assuming the air conditioning would generally be powered at 480.
One idea (if the UPS makers would do it) is for a UPS that takes 480 or 277 volts in on the AC-DC side, and produces 240 volts out on the DC-AC side. This would be a continuous online dual conversion UPS producing a separately derived system just for that one cabinet. If they can fit it in 4U to 6U of rack cabinet space, one of these could be put in each cabinet at the bottom.
