Maintenance of brushless DC motor

1. Before disassembly, clean the dust on the surface of the motor with compressed air and wipe the dirt off the surface.

2. Select the working place for motor disassembly and clean the site environment.

3. Be familiar with the structural characteristics and maintenance technical requirements of the motor.

4. Prepare tools (including special tools) and equipment required for disassembly.

5. In order to further understand the defects of the motor during operation, an inspection test can be conducted before disassembly if conditions permit. To this end, put the motor on the load for test run, check the temperature, sound, vibration and other conditions of each part of the motor in detail, and test the voltage, current, speed, etc., then disconnect the load, conduct a separate no-load inspection test, measure the no-load current and no-load loss, and make records.

6. Cut off the power supply, remove the external wiring of the motor and make records.

7. Select a megger with appropriate voltage to test the insulation resistance of the motor. In order to compare the insulation resistance value measured during the last maintenance to determine the insulation change trend and insulation status of the motor, the insulation resistance value measured at different temperatures should be converted to the same temperature, generally 75 ℃.

8. Test absorption ratio K. When the absorption ratio is greater than 1.33, it indicates that the motor insulation has not been affected by moisture or the degree of moisture is not serious. In order to compare with the previous data, the absorption ratio measured at any temperature should also be converted to the same temperature.