Jet DC1200 Dust Collector Motor Dying - Is it Fixable?

[Bryan Caruso]

I was hoping to get a little assistance from those of you that may have a little more experience with AC motors than myself. I've tested the capacitor and it appears to be okay, although I'm not 100% i did it correctly (tested it in ohms and it was showing >400 and the capacitor is a 400ufd 125V or there abouts. The bearings are smooth and the centrifugal switch seems to be working, although I'm getting serious arcing from it when the impeller is attached. It's just not wanting to come up to speed.

Do you guys have any suggestions? Is this motor salvageable?

[ken carroll]

If you're testing a capacitor with a multimeter in the ohms setting, then that applies dc to the test component. A capacitor should show an instantanious deflection
(or reading if it's digital) on the meter then go to near infinite ohms. 400 ohms sounds bad. Try to find a multimeter with a capacitance measurement setting rather than a volt-amp-ohm type.

[Charles Lent]

You can try replacing the capacitor to see if that's the problem, or find a motor repair shop and take it to them. There's usually one located near industrial locations. If the motor can be repaired they are the ones who can do it. If not, they probably have a new identical motor in stock. This will be cheaper and quicker than having us guess at what might be wrong with it. They are also the ones who will likely have the capacitor that you need if you want to try replacing it before bringing the motor to them. Take your old capacitor with you because you will need one of the same physical size as well as the same electrical parameters. They can test your old capacitor and fix you up with a perfect match replacement, if you need it.

Charley

[David L Morse]

I think it's not fixable. Based on your symptoms it sounds to me like a piece or pieces of the shorting rings have broken off the rotor and are rattling around inside. The missing chunks leave some number of rotor turns unshorted and thus unable to carry current. This reduces the amount of torque that can be delivered to the load. Depending upon how many turns are missing the motor can appear normal with no load (other than the noise) but unable to bring the fan up to speed (a fan's torque requirements increase with the square of RPM).