My 2HP Rikon band saw motor burnt out a capacitor. I replaced it and it worked, but that did not solve the problem. It just hums… I don't use it that much. Any ideas?
From contributor S:
Troubleshooting Rule #1: Always check the simple things first!
Check your incoming voltage. Check the rest of the saw mechanism for obstructions or resistance. Make sure the new capacitor meets the required ratings. Just because the capacitor is new does not mean it was not defective - try another one after you've checked everything else. If you blow another capacitor, you likely have an internal motor issue, but you still need to check everything else before you pull the motor. Once you get the saw running, check the current draw.
Seeing how I don't use it very much, I feel I should have just bought a Grizzly or other brand now. If blowing it out doesn't make it work, I guess I'll take it to a motor place here and have them go through it. Might be cheaper than a new motor.
It might be useful to measure the current draw and voltage *at the motor* while you have it running.
I don't know what a start capacitor costs these days, but it might be worth buying another new one on the (better than average) chance you got a defective one - just make sure you buy a different brand this time, as it's possible the manufacturer made a large batch in which all were defective.
For what it's worth, marketing gurus can increase their motor horsepower claims simply by installing a capacitor of a different microfarad value.
Spinning by hand will tell you if the main run windings are okay. Spin first, get your hand out of the way, then apply power. Sometimes the contacts get a little corroded. Some 600 grit emery cloth will clean it up just fine.
On the Grainger website, capacitors range in price from $7 to $33, with most being $10 or less.
If the motor will spin start, then he could take the old capacitor to the motor shop and have them test it - then he'd know what the next step would be. If the motor will spin-start and the cap tests good, the next logical step (for most people) would be to take the motor to the repair shop.
Comment from contributor A:
I had the same symptoms with a table saw motor. It turned out that the centrifugal clutch was dusty and wouldn't grip the armiture. Take the cover off the front of the motor (covers the fan). Remove the fan (set screw) and behind the fan is the centrifugal clutch. Blow out the dust with compressed air, put the fan and cover back, and try it.