What are the common faults of variable frequency motors?

Common faults of variable frequency motors include:
1. Inter turn short circuit and partial discharge: This is a common form of insulation type faults in variable frequency motors. Interturn short circuit is generally manifested as extensive damage to a coil in the motor, while partial discharge may occur when the motor coil looks good outside, but the insulation resistance has already shown zero.

2. Bearing damage and excessive vibration: Due to the operation of the PWM inverter drive system, the problem of bearing damage in the inverter motor may become increasingly serious, even leading to excessive vibration. This problem is more common in some high-speed variable frequency motors.

3. Overload fault: When the load is too large or suddenly increases, the frequency converter may experience overload faults, causing the motor to malfunction and even damaging the frequency converter equipment.

4. Overheating fault: Prolonged operation or high ambient temperature may cause overheating faults in the frequency converter. Overheating can damage the internal components of the frequency converter, and in severe cases, it may even cause a fire.

5. Voltage imbalance fault: Asymmetric three-phase voltage can cause uneven voltage impact on internal components of the frequency converter, thereby damaging the equipment. This type of fault may be caused by voltage imbalance in the power grid.

6. Overvoltage/undervoltage fault: When the grid voltage is abnormal, the frequency converter is prone to overvoltage or undervoltage faults. Overvoltage may cause equipment damage, while undervoltage can affect the normal operation of the equipment.

7. Stall/Over speed Fault: When the frequency converter is unable to control the motor speed or the motor speed exceeds the set range, a stall or over speed fault may occur.

In addition, variable frequency motors may also experience other faults, such as short circuit faults, overcurrent faults, circuit board failures, control chip failures, relay failures, etc. In order to maintain the normal operation of the variable frequency motor, regular maintenance and inspection are required to promptly detect and handle these faults.