Three Phase Converters

[930dreamer]

I've been messing around with these three phase motors for awhile, I can't seem to leave well enough alone. I use them to run a 5 hp three phase compressor.

I replaced the bearings in the 10 hp motor on the left and painted it. The other is a 7.5 hp, I welded up the frame with some 1/4" angle iron. The motors are wired in parallel and each has a disconnect. I start the 10 hp with a pony motor and the other will self start.

The frame has a little wobble which makes the motors rattle, I guess the motors need to be bolted down to the frame with some rubber as a dampener.

I'll probably disassemble again and use 6 ga. wire, and feed it into a three phase panel I found.

http://s228.photobucket.com/albums/ee137/3CL1/?action=view&current=RPC121910001.mp4

 

[jabberwoki]

Yeah i love that old industrial stuff to got a big 5hp pedestal grinder but i`ve not hooked up a converter yet. How do you handle the change from 220 to 440 that's what my grinder needs?

 

[fflintstone]

I've been messing around with these three phase motors for awhile, I can't seem to leave well enough alone. I use them to run a 5 hp three phase compressor.

I replaced the bearings in the 10 hp motor on the left and painted it. The other is a 7.5 hp, I welded up the frame with some 1/4" angle iron. The motors are wired in parallel and each has a disconnect. I start the 10 hp with a pony motor and the other will self start.

The frame has a little wobble which makes the motors rattle, I guess the motors need to be bolted down to the frame with some rubber as a dampener.

I'll probably disassemble again and use 6 ga. wire, and feed it into a three phase panel I found.

http://s228.photobucket.com/albums/ee137/3CL1/?action=view&current=RPC121910001.mp4

Your link was to the whole album, not your phase converters. i got bore by the 3rd pic.

I have a large drill press with a 3 phase motor, and an unpowered gynormus lathe that came with an unattached 6hp 3 phase.
I was thinking of making a phase converter but it seems like a huge hassle.
I think I am just going to put single phase motors on both.

 

[Griff93]

It's really not that big of a hassle to make a rotary phase converter. I've heard several older machinists talk about a 3 phase powered lathe making a smoother finish due to it's power overlap. If you already have a three phase motor for it and can find a large enough motor to make a converter for a reasonable price that's what I'd do. The nice thing about trying to find a three phase motor is most people can't use them and don't want them so they are usually pretty cheap. Another nice thing about three phase is you can reverse direction while still in motion. You can't do this with single phase as it will just pick back up in the same direction.

 

[Possum]

A RPC with a rope or pony motor start is about the simplest thing you could make. If you have a "dumb" machine with out any complicated control electrics they work great. If you have a piece of equipment with a step down 120V transformer running contactors, relays, etc. I would make sure the two leads running to it are the supply lines from your service and not the third generated or "wild" leg. A 6hp lathe that uses a clutch would run fine off a 10 hp (idler motor size) converter, one that is direct drive would probably need a 15hp for the heavy start load.

Your link was to the whole album, not your phase converters. i got bore by the 3rd pic.

I have a large drill press with a 3 phase motor, and an unpowered gynormus lathe that came with an unattached 6hp 3 phase.
I was thinking of making a phase converter but it seems like a huge hassle.
I think I am just going to put single phase motors on both.

 

[klhitman]

I would just buy a oversized VFD. The ones that I have used will take single phase in and put out 3 phase and you can control the speed if need be. But you have to step up the vfd size to get the full speed or you will get a fault.