mr colt

in my manual is says that i need a 30 kw engine drive for full arc stretch, using a
rotary phase converter is it still 30kw? the manual shows that 480 volt takes 34 amps during arc stretch, so it i take those #s i get 16.32kw. at 208 its 15.6kw.
i just need to know if i need to have a rph that is 30 kw to run or if my kw figuring is right and i can size one to that.

thanks for your help
bakerj99