Van Norman 12

You'll need to measure the voltage of the three phases at the motor and see if one is low or missing
Obviously, be careful
 
Okay, Thought I measured before on old motor and it was good, I'll check again on new motor.
 
They won't be exactly the same voltage, since one leg is "manufactured" by the RPC
You are looking for a very noticeable difference
I don't know much about troubleshooting starters, one of the heaters could be open circuit I suppose
I presume they can be checked for continuity- with power off of course
 
Alright, just did some more work.

I started measuring the voltage from the contacts to motor side and noticed that the voltage was a bit lower on two of the wires, so about 170. I took the contacts apart again and really polished them. I was able to get the voltage on T2-T3 to 220 T1-T3 to 220 and T1-T2 to 200v, not really concerned with that.

Motor is still sluggish. The lines from the motor side contacts are pulling between 5-6 Amp, the motor rating is 4.6A for 220. Hence why the heaters are glowing and tripping the coil magnet.

Not entirely sure where else to look.

How would I measure those older style heaters. L shaped bracket with wire wrapped around a piece of silver fabric.

Thanks
s-l1600.jpg
 
Found the problem.

Turns out it really is just old grease in the spindle head. Being in an unheated garage really does a number on it.

So in my infinite wisdom I thought the highest rpm would be easier for the motor to turn. Turns out being in low rpm gives the motor more mechanical advantage. And was able to turn without drawing over current.

While the second to highest setting still was able to turn while motor was pulling about 5 amps I got it to warm up the head enough that it was able to turn at highest rpm.
 
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