Phase converters are available in static and rotary style. Static converters are cheaper but also do not result in full motor power. Static converters only run wye motors, not delta motors as I remember. Depending upon your motor size, a rotary phase converter starts at somewhere in the $400 range for a 1 or 2 hp unit. The static converters are cheaper but much less efficient. Like Denny said, a motor change may be the easy way out. A 5 hp single phase motor draws 22.5 amps if my memory serves me....you would have to put it on a 30amp breaker with the correct size wiring. If the motor is bigger than a 5, the motor gets pricey.....this is why 3 phase stuff sells only to industrial power hookups.....