1Ph or 3 Ph electric motor - How do I tell which ?

Is there a capacitor on it? Can you post a picture?

You mean you connect three terminals with three phases, or what?

When it runs, do you hear any unusual sounds from it (kind of hard due to the noise of the saw, but maybe you can remove the belt or some such)?

Check the amps to see if its pulling what the plate says...

Hi to answer your questions.....

I just connected to the domestic 240 volts. I assumed Red was +'ve and Blue -'ve that left grey which I connected to earth. No capacitor.

It ran OK no noises, I just don't know if this is at full power or full speed. I havn't connected to the band saw yet, it is just sat on the kitchen table I have a very understanding wife, so far .

Re add a picture,,,,,, don't know how to do that. I will ask my son.

Regards,

I will try tomorrow and let you know.

Thanks, Regards,

If it has a centrifugal starting switch then it is a 1-phase motor. If it has no centrifugal switch, then there are several possibilities. But, the big one is the motor RUNS on single phase (I assume that is what you are saying above). If it starts briskly in the same direction every time on single phase power, that pretty much guarantees it is truly a single-phase motor. I'm wondering if it is a multi-speed motor.

Jon

If it starts under load on single phase, it is NOT a 3 phase motor.

Since the voltage range is related by sq.root of 3 (220 x 1.7320 = 381) it appears to be a 3-phase motor connected in delta for the low voltage and connected in star for the high voltage input. It appears that both ends the 3 windings are brought out so that either connection can be easily made. An ohmmeter check will verify my supposition quickly. In the UK, is residential supply 3-phase 220V, with one leg grounded? If so that should explain why you are able to get it to run.

Randy