Phase Converter

[lanham]

Can anyone tell me what the best and cheapest way to go on converting to 3 phase power.Are static converters any good? This is going to power a 7.5hp lathe.Thanks

[kwkracing]

I would highly not recommened using a static converter. i have been running a 2 hp motor with them. I have tried atleast 4 diff brands and none last any longer than another. They have all lasted about 2 months at a time with just occasional use. Get a rotary converter or buy a big single phase motor and be done with it, thats what i finally did.

[rob41willys]

Rotary converter for sure.

[lanham]

What kind of rotary setups are you guys using.

[rob41willys]

I had a local guy build mine. cost me $500.00 but I already had a big 3-phase motor. That was several years ago. but still running fine.

[racecrafter]

rotary converters are better for high horsepower aps but I have been running an electronic phase converter on my 5 horse mill for about 7 years and still going strong .....just make sure you wire it right and use big enough wire...in and out....it has been so long since I have looked at it that I don't remember what brand it is but I will try to remember to look and let you know the next time I log on. With 7.5 horse you are on the edge of what I would run with an electronic though.

[shinyblackpaint]

I built my own roto-phase years ago. Very simple. First one was a 5 hp. It ran two lathes and a mill. I sold one old lathe and the roto-phase. So I built a 10 hp. I then got some more machines (and larger) so I sold the 10 hp and built a 20 hp. It ran my entire machine shop. 3 mills, 3 lathes.
Just need a bank of capacitors on the manufactured leg. That takes a little playing around with different size micro-farat to end up with a close to balanced voltage across the legs. The more motors running at one time makes it more efficient and balanced voltage. I would always start the larger motor first then start up any smaller ones. Worked awesome until I got some CNC equipment then the power just wasn't clean enough for that so finally brought 3 phase in the shop. However they are the best thing for running electric motors.............the more the better.