Can you describe the procedure for overhauling a three phase induction motor?

The only preventive maintenance that can be done to electric motors by maintenance personnel is to disassemble the motor. The motors bearings can be cleaned and re greased or if sealed bearings that can be changed out for new ones. Remove any grease or dust build up from the stator with compressed air. The stator then should be washed out with a solvent that is specifically made for cleaning electrical equipment. Dry the stator making sure that the motor coils have room around them for air to flow. Dirt accumulations around coil wiring insulation is the biggest cause of motor failure. The coil wires need cooling air moving across them. With totally enclosed motors the cooling vanes on the outside of the motor need to be kept clean as they are the only means of removing the heat from the motor.