1, the motor can't rotate after being electrified, but there is no abnormal sound, odor and smoke. The reasons for the failure are that the power supply is not connected (at least two phases are not connected), the fuse is blown (at least two phases are blown), the overcurrent relay is adjusted too small, and the control equipment is connected incorrectly. Troubleshooting Check whether there are breakpoints in the switches, fuses and junction boxes of the power supply circuit, repair them, check the fuse model and fuse reason, replace the new fuse, adjust the relay setting value to match the motor, and correct the wiring.

2. It is difficult to start the motor. When the load is rated, the motor speed is lower than the rated speed. The fault causes include low power supply voltage, wrong connection of the face-to-face motor, open welding or fracture of the rotor, wrong connection and reverse connection of the local coil of the rotor, too many turns when repairing the motor winding, motor overload, etc. Troubleshoot, measure power supply voltage, try to improve and correct connections, check open welding and breakpoints and repair them, find out wrong connections and correct them, restore correct turns and reduce load.