How should I wire a 3 phase motor?

Question

The green wire goes to green. The red wire goes to red. But the two black line wires.....if I get them reversed is the only ill effect that the motor runs backwards and I can simply reverse them?
Also.....I'm using single phase 240 V to power up a rotary phase converter to run it. The meat saw motor is 2Hp 3 phase. The rotary phase converter has a 3Hp, 3 phase, 15 amp output, so that's good, but what size of circuit breaker should I use in the breaker box? 20amp? 30 amp? I don't know how many amps I lose in the conversion to 3 phase.

Answer 1

You have a 50-50 chance of getting it right, and There's no way of telling in advance which is right. If your color coding were red, blue, black on both the converter and the motor, then you could be reasonably certain of getting the wiring correct on the first try, but no motors I've seen come that way. Simply swap 2 leads if the saw runs backwards.

If the saw is a band saw, you could flip the blade running it backwards, so make your test run short.

Estimating current,
I ≈ (0.746 KW/hp)(3 hp)/(240 V)(0.8 p.f.)
I ≈ (0.746 KW/hp)(3 hp)(1,000 W/KW/(240 V)(0.8 p.f.)
I ≈ 11.656
11.656*1.25 = 14.57, so you should probably be using a 15A/2P breaker. Recheck the data plate on your converter for rated current, and multiply by 1.25 for breaker size.