There are many reasons for motor heating, which is usually accompanied by abnormal noise and a burnt smell. At this time, the power should be immediately turned off and the use stopped. Careful inspection should be conducted to identify the cause of the fault, and one must not be careless or negligent.
The heating of an electric motor can be attributed to 21 different reasons:
1. Room temperature is too high
2. Poor heat dissipation
3. Overload
4. Overvoltage, undervoltage, or voltage imbalance
5. Frequent start-stop or frequent forward and reverse rotation
6. Phase loss
7. The fan is broken or the air inlet and outlet are blocked
8. Lack of oil in the bearing
9. Mechanical jamming and locked-rotor
10. Excessively large load moment of inertia leads to excessively long startup time
11. Inter-turn short circuit
12. The internal wiring of the new motor is incorrect
13. The star-delta connection is incorrect
14. The star-delta or auto-transformer step-down starting load has a long restart time or fails to switch normally due to a fault
15. Motor is affected by moisture
16. Broken rotor bars in squirrel-cage induction motor
17. Broken wires or unbalanced resistance in the rotor winding of wound-rotor asynchronous motor
18. Rotor rubbing
19. Excessive power supply harmonics, such as the presence of large rectification equipment or high-frequency equipment nearby
20. The magnetic flux of the motor core decreases after multiple repairs
21. Some motors have poor winding processes
Elevated motor temperature caused by other non-mechanical or electrical fault factors may also lead to motor failure in severe cases. For instance, high ambient temperature, absence of a fan, incomplete fan, or missing fan cover. In such cases, forced cooling to ensure proper ventilation or replacing the fan blades is necessary; otherwise, the normal operation of the motor cannot be guaranteed.
In order to adopt the correct method for motor fault handling, it is necessary to be familiar with the characteristics and causes of common motor faults, grasp the key factors, conduct regular inspections and maintenance. Only in this way can we avoid detours, save time, quickly eliminate faults, and keep the motor in normal operating condition. Thus, normal production in the workshop can be ensured.