So, all you electricians, what size of converter do I need to install?
It depends on the type of converter. What everyone has been talking about so far are rotary converters and they work fairly well and are relatively cheap, but need to be over sized and may not be able to start large motors if your electric service is not up to it.
Because of my remote location I opted for an electronic converter. This allows me to run any load with out the voltage on the wild leg varying, it has PFC (no nasty inductive load that the power company hates and it helps tremendously with the inductive starting current) and it's much nicer on the AC motor since the voltage is almost exactly balanced (gives balanced currents). The disadvantage is they are more expensive. Yah, I know you wanted a cheaper alternative. Sorry, but in this case better costs more!
Here's a link to what I got
http://www.phaseperfect.com/. They have units that go up to 60HP and will deliver from 0 - full HP with no significant change in the generated voltage/phasing.
If you want more information or want to discuss this in more detail let me know. If you want to order a unit let me know. I think I may have a discount card in my office some where. If you or you student (electrician) want to stop by and see what I have and how it's set up let me know, but now's probably not a good time. We are approaching 3 feet of snow so you may want to wait for a bit of thawing before making the trip.
Have a Merry Christmas,
Cary