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can you convert single phase to three phase easily? Answered

I have a three phase lathe, but only single phase in my shop. Is there a way to easily convert single phase to three phase?


I would not go to single phase!!!! You will be blowing motos left in right. Look up cerus drives and go that route. They are the least expensive on the market.

I'm in exactly the same boat you're in.  I am also buying a lathe with a 3-phase motor.  I've also investigated the rotary converter, but am not really impressed.  Being as my lathe was built in the 40s or 50s, I doubt I'll find a single phase motor just like it.  I've decided to go with the VFD or variable frequency drive.  I am an electrician and recently worked in a potash processing plant, where we used about 500 motors in the whole process.  Almost all of them were put on VFDs, and I was very impressed with their capabilities, especially for larger motors.  For a smaller motor, you can find VFDs that are fairly inexpensive, and still have quite a few capabilities that you probably won't need or use.  The VFD will protect itself and the motor from almost every conceivable electrical malfunction, and will protect the motor from overloads also.  You  might start with Elliott Electrical Supply, which has dozens of stores in Texas, and go from there.  Or just google variable frequency motor drive.  Best of luck!

You need a phase converter as others have suggested. A friend of mine also needed three phase for a CNC mill he purchased.  He bought and had the converter installed by our local power company, so that may be a place to start or they could point you in the right direction.  It wasn't cheap though (I believe between $300 - $400 USD).

Depending upon how large a lath/motor you are talking about, there are ways to DIY convert and drive the motor with single phase with a run capacitor. There is a whole book chapter devoted to the subject in Jim Cox's book, Electric Motors (workshop practice series).  You will sacrifice some horse power doing it this way, but with a bit of faffing it can be done quite cheap. 

Easier option is a motor drive inverter, also called variable frequency drive, and a few other names. These are expensive (anywhere from £100-£500 depending on wattage), but good, as far as I can tell.  They have the advantage off conveniently allowing you to control the speed of the motor without changing pulleys or anything like that.  They also supply true 3 phase, so the motor runs smoothly and efficiently.

You can also get rotary phase converters - these tend to be heavy, noisy, significantly less efficient (unless you are somehow harnessing the rotation of the converter - say by driving a dust extractor). 

Of course the other option is, as RavingMadStudios says, to replace the motor.  To me this would be a bit of a waist, unless of course you happen to have a good single phase motor and control gear knocking about already...

You can buy a static phase converter and have an electrician install it for you, but opinions are mixed on whether these devices are really safe and effective for this purpose. It might be easier, cheaperand safer  to rewire or replace the motor on the lathe so that it works on single-phase.