1. Use an insulation resistance shaker to check whether the insulation resistance of the motor coil is greater than 0.5 megohm. If it is greater than 0.5 megohm, it means that the motor has good insulation performance;
2. Use the resistance gear of the multimeter to test whether the DC resistances of the three windings of the motor are the same. If the DC resistances of the three windings are the same or the deviation of the DC resistances of the three windings is small, it means that there is no inter-turn short circuit between the coils of the three windings;
3. Manually turn the shaft of the motor to check whether there is no movement, abnormal noise, etc.
4. Check the quality of the motor
1) Use an insulation resistance shaker to check whether the insulation resistance of the motor coil is greater than 0.5 megohm. If it is greater than 0.5 megohm, it means that the motor has good insulation performance;
2) Use the resistance gear of the multimeter to test whether the DC resistances of the three windings of the motor are the same. If the DC resistances of the three windings are the same or the size deviation of the DC resistances of the three windings is small, it means that there is no inter-turn short circuit between the coils of the three windings;
3) Manually turn the rotating shaft of the motor to check whether there is no movement, abnormal noise, etc. The fourth step is to energize the motor with no load, check whether the 3-phase current of the motor is balanced, whether the motor runs smoothly, temperature rise, abnormal noise, etc. , after the above 4 steps of inspection, if all are normal, then the motor is good.
