Sorry. I meant to reply with quote:
"1. . The
dimmer pack may operate on either 3-phase, 4-wire +
ground, 120/208V, 50/60Hz AC or 1-phase, 3-wire +
ground, 120/240V, 50 or 60Hz, AC
at an amperage sufficient to
power the pack.
The
NEC is setup to prevent fire & personal injury
You have a
dimmer that requires a 160A service. You need over-current protection closer to the 160A
rating to be safe.
If there were a short or over-current say 200A the 400A fuses wouldn’t care but your
feeder cables would."
I can't make best recommendation without an idea if: this is a one time or infrequent set up or if you will use this regularly, say at least two events per year; and what kind of load do you anticipate - two 575s per
dimmer or less or more?
I think the suggestion that the rack is rated for 400 amp feed should be verified but a set of feeders for that is the easiest and least expensive and per code. But if using often and especially if a new feeds in someone else's budget thana dedicated
receptacle or hard wiring the rack is not a bad choice - tapping off the co sw feed or other. I would be concerned about distribute back to rack and noise. No doubt installing in a separate room and installing a permanent
distro would be best but most expensive. In which case 100 or 125 amp 3 pole is probably fine but tell us how you think you'll loa it.