PM2000 motor stops randomly

[jussi]

Last year I picked up a used PM2000. Looked great and the motor ran great. Most of the time it still does. But occasionally, maybe 10-15% of the time the motor just shuts off a few seconds after it turns on and won't turn on again. You have to wait a couple of minutes and sometimes unplug it. Again it doesn't happen often but it does happen.

Today I installed a dado stack for the first time. Total blade width was just under 3/4", so it was kind of a big blade. It was late so I didn't use it very much but this time the shut off rate was closer to 50%. Again I didn't use it much. Actually only 3-4 cuts to get the exact dado width I needed.

Any hints on what's going on.

[EricU]

I wonder if it's a centrifugal switch problem or a cap going bad

[AHill]

Might be a faulty thermistor or whatever component turns the saw off when the motor overheats.

[BloomingtonMike]

Is the motor starter's contactor still latched when this happens? If so the overload below it is not tripping it. You could also test the voltage at the motor with a meter when it happens if you are so inclined and knowledgeable enough to safely do it.

[EricU]

the overload is in the contactor and there isn't one in the motor? I looked a the manual, and I couldn't figure that out. One site I looked at mentioned that sawdust buildup can be a problem. I would definitely look into that.

[jussi]

Thanks for the suggestion. I'll try and blow it out and see if that helps. I'm in the middle of a project right now that I need to finish asap so any major repairs will be a big problem for me.

[BloomingtonMike]

Pretty easy to check. Unplug saw and unscrew cover off the starter.

The thermal overload plugs in under a contactor. Almost all motor starter boxes have them these days. Here are some pictures of them.

http://www.factorymation.com/Products/TE...ds-6-300A/

[JGrout]

I believe I know what the problem is

the contactor box for that saw has a variable amp output and it has moved ( vibrated) to a lower setting than the sawmotor is designed to operate on.

I have had this occur on planers when the knives were to dull and the wood was being pounded instead of cut.

I can see it happening with a TS.

If you open up the box it is fairly easy to locate and adjust.

Joe

[jussi]

I called powermatic and they said what you suggested or that the belt needed to be tightened. I tightened the belt and then opened up the switch but unless I'm missing something it's already at it's max value. I can turn the switch more but there aren't any numbers as you can see below.

So I left the electronics alone and tried starting it again. Turned it on and off 10 times with dado stack attached and it tripped twice.

I read a few older posts on SMC saying they called powermatic and were sent a whole new switch. Being mine is second hand I doubt that will happen for me but I'll give them another call later on the week and see what they say.

[jussi]

I forgot to mention that when this happens the motor starts much slower / weaker than normal. Then a few secs later it shuts off.