How to Build a Rotary Phase Converter

[mr herb]

The bearings in your 20hp motor sound rather tired. Are you going to put it outside your shop? I wouldn't want to have to listen to it all day.

While safety should be important, 47 years ago I built my first rotary converter, and never had all that complexity.

A delta wound motor works better than a star wound motor.

I have seen installations where the initial run up was provided by a rope wound around a pulley--like in an old lawnmower

I prefer a one half hp motor to do the spin up, then it can be disconnected, or just left running.. It wont draw that much.

Balancing the phases with no load connected wont do much, as any change in the load that your "floater" motor sees would require different capacitors. Better to balance with your largest tool motor running.

If your wall power goes off, and you have enough sense to turn off your lathe, I would hope that you have enough sense to turn off your converter motor also. If not maybe you should take up gardening.--Not you Bob, the you is directed to a reader

Bob, I'm not trying to criticize what you you did, you built a beautiful unit. I just afraid that you will scare off some fellows that want to convert single to three phase, but will get worried that it is too complicated. There are those that have enough sense enough not to stick their fingers on live terminals. There are a lot that don't have that sense, and realize it. This is not for them.

mr herb