Welding Tips and Tricks

I recently purchased a Miller CP-300 Mig machine with wiring options for 460 or 575 volts, 3 phase. I have 3 phase but, it like, 120-208-230v. I need to confirm this again. Does anybody have exsperience with this and using stepup transformers? I really want to use this machine if at all possible. Its in excellant condition and I got a great deal on it. Besides, its exactly what I wanted being old school, the only forms of MIG I really appreciate are obtainable with this old machine.