Reply by John Ormsby

I recommend you get a Kay Industries converter. They are great and will last forever. By going with a 3-phase converter you will be able to get other 3 phase machines much cheaper and easier than 1 phase ones. Kay rates their converters as to how much motor they will start, and not the maximum total HP the converter is capable of running. You can run multiple machines on one converter. I would think a 7 1/2 to 10 HP converter would work.
Some people buy the larger 25 HP versions in order to run a wide belt sander. Kay also has a model that balances out the 3rd leg so as to make the voltages almost equal. This is important for some types of electronics on some machines.

Be aware that other converter companies usually rate their machines as to the maximum total HP can be used. It is very misleading. You must get one that will start up your motors. Also, the general rule is that the heavier the converter weighs the better. Mine weighs about 260 lbs. The 7.5 HP model is a MA-1B and the 10 HP model is a MA-2

-- Oldworld, Fair Oaks, Ca