Simple Question from a Simpleton :-)

If the motor came out of an A/C with the extra wire I'd suggest that it is either a cap start motor or a 2 speed motor. Tough to tell which wihtout some more details. About the best I could say is that the cap lead is typically brown.

Dale Hallmark wrote:

It is pretty small (abt 7 inch in diameter) and looks like a million other

110-v motors I have seen. But red white black wiring is not something I recognize.

Dale

No Brown wire present. Two speed makes sense, maybe :-) But it wouldn't turn so maybe I need to try the red wire (slow, maybe). slower the better for me.

So Black to black, white to red and green unconnected to white. If it ruins it, haven's lost a cent.

Or White to Black, Black to Red and green unconnected LOL

Dale I am easily confused :-)

That sounds like three phase -- either 220V or 440V. And you need to make a separate safety connection to the motor's frame -- *that* should be green in the US.

That is a standard 120V single phase cord.

But given enough time, it would burn out the motor's windings. You need either real three phase, or to fake it out with start caps and circuitry to remove the caps once it is spinning.

For 120V lines, right. Green is the safety ground.

No -- all three of your wires are for different phases of a three-phase feed. Difficult to get in a residential setting, though there are several ways to fake it. (Look back in the archives of this newsgroup for "rotary convertors" and VFDs.

Check the resistance between the three wires with a low-range ohmmeter. They should be identical between any pair, if it is a three phase motor.

Don't trash it -- if nothing else, it can be used as the basis of a rotary converter to run a smaller three phase motor on some machine tools which you may acquire later. Once you have the motor to use as an idler, the rest of it is pretty cheap to build.

Or you can fake it to start with capacitors, and live with losing 1/3 of the full horsepower rating.

To test this -- wire it up with a switch to put 220V on two of the three wires (any two and insulate the third wire for safety), but leave the switch off. Wrap a rope around the shaft, and spin the motor by pulling on the rope, and while it is still spinning (but the rope is clear) switch on the power and see if it spins up. If so, you are pretty sure that it is a three phase motor.

Good Luck, DoN.

Could it be 220V? Black (hot), Red (hot), White (Neutral). Ken.

Well, three phase, or 220; it is worthless for my purposes. I will see if I can trade it for something I can use.

My shop (a do it yourself shop in the corner of my garage) has neither and I have no need of them so far for any project I have planned.

Thanks for all the responses! Dale

Just a couple of things to consider before getting rid of it:

1) Some of the better used machine tools come by default with three-phase motors, and while you can swap in a single-phase motor in some, in others, it is a custom motor, and a single-phase equivalent may be difficult to find.

And used machines which have been converted to single-phase cost more (because of the motor cost).

So -- having the ability to construct a rotary converter can save you money in the long run.

Also -- three-phase can be *quickly* reversed (e.g. when threading up to a shoulder), while single phase must be switched off, allowed to coast to a near stop, and then switched into the other direction.

2) Even 240 can help you with current problems, because for a given horsepower, 240 will draw half the current that 120 will draw. When I got my 12" Clausing, it was wired for 120V, and I had problems with occasional circuit breaker trips when I switched it on. I re-wired it for 240V, and no problems.

Though I do plan to eventually replace the motor with a 3-phase one, so I can do instant reverse.

Enjoy, DoN.