ac motor runs then stops loud hum?
humming usually indicates a locked rotor ,If this is so figure on a new motor.
Either the load is on and is stuck, or the motor bearings have seized up. Do NOT run the motor until you have sorted the problem, or you will ruin the motor windings. XX
It seems like the bearings are getting hot and causing the motor to seize up. Is there any place to oil the bearings? That may help
