After the motor runs for a long time, various failures will occur. To determine the cause of the failure in time and deal with it accordingly is an important task to prevent the expansion of the failure and ensure the normal operation of the equipment.

　　When the motor is running, pay attention to observe whether the motor emits smoke, violent vibration, too much noise, and the temperature around the casing and the bearing is too high. If it occurs, it indicates that the motor may be malfunctioning. It is necessary to cut off the power in time to check whether there is a short circuit in the stator windings and the motor. Whether it is overloaded or operating under phase loss, whether the three-phase current is balanced, whether the iron core is loose, etc.

　　If the motor vibrates greatly during operation, the possible causes of failure are (1) rotor unbalance; (2) iron core deformation or looseness; (3) fan unbalance; (4) cage rotor open welding short circuit; winding rotor open circuit ; The stator winding is faulty.It must be corrected and repaired in time.

　　If the motor is difficult to start, and the speed is lower than the rated speed under the rated load, the possible causes of the fault are: the power supply voltage is too low, the connection method is wrong, the cage rotor is open or broken, the stator and rotor local coils are connected or reversed, and the motor is overloaded. .It is necessary to find out the reason and correct it in time.