I have a GE DDE7208 dryer with a 5KH26JJ motor. When the motor is stationary, the centrifugal switch energizes the start winding along with the run winding. When I depress the starter, the motor hums but does not turn even with the belt off. That points to a bad motor, but I want to be sure.
Winding resistances are 3 and 4 ohms. That doesn't prove the insulation is holding up at 120 VAC, but if there were a leak so bad that the motor wouldn't turn even unloaded, wouldn't the overload protector break the circuit?
At 2 amps DC, there are only 6 mv across the centrifugal switch, so the contacts appear to be fine.
Bearings have no slop or noise but more friction than some motors I've seen. It takes 0.7 inch-pounds to get the shaft moving.
What could be wrong?