1. The room temperature of the motor is too high

2. Poor local heat dissipation of the motor

3. Motor running overload

4. Overvoltage and undervoltage or unbalanced use voltage during operation

5. Frequent equipment start and stop or frequent equipment reversal

6. Motor phase loss

7. The motor cooling fan is broken or the air inlet and outlet are blocked

8. The internal bearing is short of oil

9. The inside of the machine is stuck or blocked

10. The load moment of inertia is too large or the operation start time is too long

11. Short circuit between motor turns

12. The wiring inside the motor is wrong

13. The wiring of the star triangle is wrong

14, the motor is damp

15. Winding disconnection or unbalanced resistance caused by the rotor of the wound asynchronous motor

16. Sweeping of the rotor occurs

17. The dead-core flux reduction caused by the repeated maintenance of the motor

18. Some motor winding process is too poor