I was making chips today on my 8520 and all of a sudden everything stopped and the motor would just hum. It won't even do that in reverse. Apparently the thermal protection didn't protect very well that motor casing was almost to hot to touch. Well, it's smoked, I'm sure of that. I called a guy about a rewind but he hasn't called me back yet. It's a 3/4 hp Baldor motor. A new shiny one is around $300 I don't know what a rewind will cost. So other than this bad news, I actually have a question. Motors are not my strong point. If I have to go the new motor route, is there any harm in upgrading the horsepower? Say a 2 or 3 horse motor? I'll keep the RPM's the same but I would think with a higher HP motor, it would labor less and stay cooler. Can that damage the machine at all? What are any pro's and cons?
If the motor was running when it decided to stop and it hums but does not turn, it is most likely the run capacitor and not the Start Capacitor or a burn out.
A quick check with the multi meter (on cap setting) on the removed capacitor would verify if it is blown. Make sure the capacitance is the same value but the voltage could be of a higher rating but definitely not less. A voltage higher rated cap seem to make them more reliable. Try not to use chinesium brand as the quality/reliability does vary a lot.
Remember smoking motors is bad for your health