Motor overload fault and cause analysis

Motor overload fault

Overload fault characteristics

1. Overheating: The surface temperature of the motor rises abnormally, and there may even be a burnt smell.

2. Excessive current: The current of the motor exceeds the rated current during operation.

3. Decreased speed: The motor speed decreases, and in severe cases, it may stop running.

4. Sound and vibration: The motor produces low pitched sounds and vibrations during operation.

5. Burnt odor and black smoke: When severely overloaded, a burnt odor may diffuse around the motor, even accompanied by black smoke.

6. Winding damage: The insulation part of the winding is blackened and brittle, and in severe cases, the insulation layer is carbonized into powder.

Cause analysis

1. Overloading: The actual operating power of the motor exceeds the rated power, resulting in overload.

2. Phase loss operation: One or more phases of the three-phase power supply of the motor are missing, resulting in unbalanced operation of the motor.

3. Voltage issue: The operating voltage exceeds the allowable value of the rated voltage, causing the motor winding to heat up.

4. Mechanical failure: such as bearing damage or mechanical jamming, causing the motor speed to decrease or stall.

5. Incorrect operation during the test process: such as prolonged stalling test time or insufficient capacity of the test equipment, resulting in overheating of the motor winding.

6. Wiring error: Connecting the star connected motor incorrectly according to the triangle connection method, or testing motors with different frequencies and voltages with excessively high voltage.

7. Power supply issue: The voltage of the power supply is too high or too low, causing the winding to heat up.

8. Impact load: The sudden increase in load causes a sudden decrease in motor speed.

9. Bearing system failure: The bearing is damaged or the sweeping chamber stops rotating, causing the motor to overload.

Troubleshooting methods

1. Check the load: Confirm whether the motor is correctly selected and matched with the load.

2. Measuring current: Use an ammeter or clamp meter to measure the actual power consumption of the motor and compare it with the rated value on the nameplate.

3. Check the protective device: Confirm whether the motor starter protective device is installed and adjusted correctly.

4. Cleaning ventilation openings: Regularly clean the surface of the motor and ventilation openings to remove debris that obstructs airflow.

5. Check the motor wiring: Ensure that the motor wiring is correct and there are no wiring errors.

6. Check the power supply: Ensure that the voltage of the power supply is stable and within the allowable range.

Based on the above characteristics and reasons analysis, it should be noted that although the motor has a certain overload capacity and can withstand a certain degree of overload in a short period of time without damage, this does not mean that the motor can operate in an overloaded state for a long time. Long term overload operation can seriously shorten the service life of the motor, and even lead to motor damage. Therefore, when using the motor, its rated load and usage conditions should be strictly followed to ensure that the motor operates within the normal operating range.