[T77911S]

you have stated several different specs.
what is the compressor voltage, 208 3 phase?
you also mentioned 480v?? then you mentioned 208 into the building.
if that 100 amp breaker is in your box then you have 3 phase coming in as oppsed to 208 single phase. (or 240 single phase).
if you need more power coming into the building talk to the power compnany. (the engineer). if it is an upgrade in service they "should" do it for free. thats how i got the power to my house moved from above ground to below ground. because i added power to my garage they considered that an upgrade and they payed for the new service to my house.

$800 for a compressor and $1000-2 for an electricin to do some panel work and pull wire