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Can anyone help with info on wiring a 3 phase motor?

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Long story but a few years ago I picked up a Baldor ISR motor at a local auction for $10. It's a 3hp, 3 phase, looks brand new.

I am thinking about setting up to do some grinding or buffing if possible, so today I called Baldor for info. Turns out this is a motor they supply exclusively to Everett Industries (which oddly enough is one town over from me) and from researching their site they use it in a 10" wet abrasive saw, so I am off to a good start..

Before I make a fool of myself calling them and trying to explain why I have a motor from one of their $3000 cutoff saws, can anyone help me out with wiring this bad boy?

I believe it can be setup to run on 220, but don't want to guess and screw something up.


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......I believe it can be setup to run on 220, but don't want to guess and screw something up.

You will need a phase converter. That is why you were able to purchase it for $10.

If you build a phase converter, you will loose electricity running the phase converter.

When I have purchased a 3 phase machine at auction, I have simply removed all the electronics and installed 220 wiring, switch and motor. Simpler that way. :D
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Here is how I ran my 3 phase machine tools at home. Say you have a lathe that has a 3 hp motor on it. Find another (jack) motor that is 3hp or larger. Wire the 2 hot legs of a 220 dryer plug to 2 of the hot wires on the jack motor. Now attach those 2 wires to 2 of the hot legs on the lathe motor. Take the remaining hot legs on the jack motor, and attach them to one each of the other motor's remaining wires. Connect all of the grounds together. You now have all of the grounds hooked together, 2 legs from the plug to the jack motor to the lathe, and 2 wires from the jack motor to the lathe. I just set the plug into the receptacle, and wind a rope around the jack motor shaft. Give it a yank to pull it up to speed, and push the plug into the receptacle. The motor will continue to run on its own, now turn on the lathe as you normally would. To reverse rotation, on something like my surface grinder, just pull the jack motor reverse of what you did earlier. The difference is that a phase converter has capacitors and does not need to be pull started. It also generates a true 3 phase output. Go with a rotary as opposed to a static type converter since they are more durable, and have more applications. My friends static type would not start one of his lathes due to the electric clutch.

I ran an 18.5" Monarch lathe, and a 10x16 Clausing surface grinder for many years this way. Never saw any real difference on the power bill, and never lugged anything. When you do this you only get 2/3 of your rated hp since you only have 2 hot legs to draw from. I left my motors alone since it would cost me thousands to refit all of my machine tools, and they are large motors; 2/5/7.5HP and some of the motors would be difficult to replace due to odd rpms (5 hp-800rpm for example)

I now have a phase converter , but haven't used it yet. When I can afford to get my shop built on my property I will have 480 3 phase available. Just have to come up with the $12K to get it literally run across the street :o The transformer is $7k of that.

hang onto that motor, as it can be used as a jack motor for something else.

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well theres a few ways to do what you want i have some wireing diagrames of making a rotory phase converter which is basicaly what your doing if you interested in seeing them pm me with a email address and i'll send them to you theres several different types of ways to wire it i made a 18 hp phase converter i think when you run the motor on 1 phase its only 2/3 of the rated hp not sure though it is less

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Thanks again for all of the info.

orgtwister, Thanks a lot, I'd like to see what you have - you can email me at: chad@pirtleranch.com

In the end I think I am just going to buy a phase converter. I found this one on eBay for $75, they have excellent feedback and for my needs running at 2hp will still be overkill. In the end I will have a heck of a nice motor setup for $85.

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