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COMachinist

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The bearings are going out on my lathe, and now the motor on the PM 932M PDF is dying. It starts but it turns real slow the in about 10 or 15 sec it will speed up to normal speed. If I shut it down the it does the same thing again. I down know cap about electric motors. Could it be a cap gone bad? It kind of rattles a little when it is turning slow, until it get up to speed. I think it is out of warranty, it sat in the shop for about 13 months untill I made room for it in the shop, this spring. If it is dying, I think it is VFD 3ph time.
Thanks for any help, it is appreciated.
CH
 
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The bearings are going out on my lathe, and now the motor on the PM 932M PDF is dieing. It starts but it turns real slow the in about 10 or 15 sec it will speed up to normal speed. If I shut it down the it does the same thing again. I down know cap about electric motors. Could it be a cap gone bad? It kind of ratles a little when it is turning slow, untill it get up to speed. I thing it out of warranty, it sat in the shop for about 13 months untill I made room for it if it dieing, I think it is VFD 3ph time.
Thanks for any help, it is appreciated.
CH

Sounds like a start cap for sure. Easily replaced. Call Matt. Warranty is 3 years.

Fret not... Easy Shpeasy to fix.

Ray
 
What frame 3ph motor does it take to replace it with a 3 hp? What brand VFD is a good reliable unit for thi application?
CH
 
Ray where are the caps to replace? Are they up on the motor or some place in the boxes.
Thanks
CH
 
Should be a hump cover on the motor, cap is under it
 
What frame 3ph motor does it take to replace it with a 3 hp? What brand VFD is a good reliable unit for thi application?
CH
Ray where are the caps to replace? Are they up on the motor or some place in the boxes.
Thanks
CH

Matt will know what frame type that motor is. He may even sell 3ph replacements. The ones he used to carry were really decent and affordably priced.

If the motor has a hump or contour on it similar to what is shown, the cap is in there. If there are no contours like that, it's inside the box. I don't know if your motor has both a Run and Start cap or just a Start cap. They serve two different purposes but, your symptom sounds like a start cap. The run cap only balances-out the load to make it less inductive. When a Run cap goes bad, it usually does not impact operation.


Motor.jpg

Ray
 
Ray
My motor is big black motor with cooling fins and big square flat kind of box. Ill get a pix of it shortly. I emailed PM this evening.will know more tomorrow.
CH
 
Yup start cap, start cap blew on my PM45 years ago when I was working a project that required starting & stopping the spindle repeatedly. Capacitors don't like that. Called Matt & he told it was just a cap, would send me one under warranty, even offered to send me a whole motor if I didn't think it was a cap.

Checked the start cap & sure enough it showed dead on my multimeter. On my motor the start cap was China & the run cap was German. I declined Matt's generous offer, I just went to my local Grainger the next morning, bought a replacement cap & a run cap, they had em in stock. Replaced both & never had the issue since. They didnxt cost much, one was like $7, the other was $15.

The stock caps are hard wired & the replacement caps had blade terminals. So I cut the stock ones off, crimped on some blade connectors & simply plugged the new ones in. Now if it ever happens to me again, replacement will be very quick & simple.
 
OK Thanks guys, removed the cover on the motor box. Here is the caps I don't know what the caps do, but it stands to reason the 450vac 255uF would be the starter, and the run cap would be the 220vac 20uF cap? If I'm wrong then you will know that I speak the truth when I say I don't any thing about Motors.LOL Yes the breaker is off and the machine is unplugged, for all you safenicks. So which one needs to be replaced? I saw that the tag list IP55 enclose, is that the frame? Oh it won't run this morning it just slowly turn. So with the machines down both lathe and mill. Looks like a fishing day, taking the boat to the mountain Lake where it is cool. YEA!
CH

mill motor1.jpg


motor caps.jpg


both caps.jpg


Avatar2.jpg
 
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