JasonPAtkins
Hot Rolled
- Joined
- Sep 30, 2010
- Location
- Guinea-Bissau, West Africa
I purchased a wood jointer that has an integral 3ph motor. I would rather have had a pulley system, so that I could just swap the (possibly) bad motor out easily, but this was what was in my price range.
The guy I bought it from had a 220v RPC at his place, but he had bought the jointer from someone else and never hooked it up. It was wired 220v, but it looked like a single phase plug. However, opening up the manual contactor, it looks like someone tried to run it from 220v single phase. The plug was a single phase plug, and inside the contactor L2 and T2 were tied together. I split them back out the way they should be and changed the connector to a proper 3 phase one. However, turning it on the motor growled and spun up slowly, like a motor sounds when a phase drops out. I didn't run it for more than a few seconds, fearing the worst.
I brought it back home and tested the windings expecting to find a shorted one, however, the resistance between the three legs was consistent, I can't remember whether 3.5 or 6 ohms, but it was the same from L1-L2, L2-3, L3-1. I then rewired the motor for 460, which is how I need it once I get it to Africa and the voltage I have available to test it here. When I did that, the resistances stayed consistent still, 3.5 or 6 ohms, whichever the low voltage wasn't.
So, since getting it home, after it didn't run right on the 220v RPC, I haven't plugged it back in. Is there anything else I can check before plugging it in? If it's not smoked yet, I don't want to ruin it. I assumed it would be bad, if someone tried on single phase, but maybe they were smart enough to unplug it immediately.
What else can make a 3ph motor spin up slowly and growl as if a phase has dropped out or is weak, even when resistances are equal? Could it have smoked the contactor? I have continuity between the L1-T1, L2-T2, L3-T3 and no continuity where it shouldn't be when I press the button with power removed. I might suspect the RPC, but he was running the rest of his shop from it, apparently. The motor does spin freely by hand.
What else should I test before plugging it in for a test on 460 now that I've rewired it?
I'm in Michigan right now, not Africa.
Thanks in advance, I appreciate the breadth of expertise on PM! Sorry for a woodworking question, but I know you guys have lots of knowledge on three phase motors!
The guy I bought it from had a 220v RPC at his place, but he had bought the jointer from someone else and never hooked it up. It was wired 220v, but it looked like a single phase plug. However, opening up the manual contactor, it looks like someone tried to run it from 220v single phase. The plug was a single phase plug, and inside the contactor L2 and T2 were tied together. I split them back out the way they should be and changed the connector to a proper 3 phase one. However, turning it on the motor growled and spun up slowly, like a motor sounds when a phase drops out. I didn't run it for more than a few seconds, fearing the worst.
I brought it back home and tested the windings expecting to find a shorted one, however, the resistance between the three legs was consistent, I can't remember whether 3.5 or 6 ohms, but it was the same from L1-L2, L2-3, L3-1. I then rewired the motor for 460, which is how I need it once I get it to Africa and the voltage I have available to test it here. When I did that, the resistances stayed consistent still, 3.5 or 6 ohms, whichever the low voltage wasn't.
So, since getting it home, after it didn't run right on the 220v RPC, I haven't plugged it back in. Is there anything else I can check before plugging it in? If it's not smoked yet, I don't want to ruin it. I assumed it would be bad, if someone tried on single phase, but maybe they were smart enough to unplug it immediately.
What else can make a 3ph motor spin up slowly and growl as if a phase has dropped out or is weak, even when resistances are equal? Could it have smoked the contactor? I have continuity between the L1-T1, L2-T2, L3-T3 and no continuity where it shouldn't be when I press the button with power removed. I might suspect the RPC, but he was running the rest of his shop from it, apparently. The motor does spin freely by hand.
What else should I test before plugging it in for a test on 460 now that I've rewired it?
I'm in Michigan right now, not Africa.
Thanks in advance, I appreciate the breadth of expertise on PM! Sorry for a woodworking question, but I know you guys have lots of knowledge on three phase motors!