How to judge the quality of the three-phase asynchronous motor coil

There are actually many aspects to the quality of the motor. The specific judgments are simpler and the following points are for your reference.

First of all, summarize how to judge the quality of the three-phase asynchronous motor coil, and what instrument to check:

1. Multimeter: used to check the on-off measurement of the motor coil.

2. Single arm bridge: Accurately measure the coil resistance, you can know whether the resistance of each phase coil is close.

3. Megohmmeter: used to measure the insulation resistance between phases of the motor and between phases to ground, not less than 0.5 megohms. Use a 500V megohmmeter to measure the insulation resistance greater than 0.5M, which means it is good. If it is lower than 0.5M, it means that the motor is broken, but this is only an appearance judgment. For inter-turn short circuit and phase-to-phase breakdown, only disassemble and disassemble inspection.

Motor failures are nothing more than two major components: mechanical and electrical.

How to detect the quality of the motor?

1. Shake the meter: 500V shaker is enough. The insulation resistance of the wires on the three terminals to the motor shell should be above 0.5M ohms, which means that there is no short circuit to the ground.

2. Multimeter test: measure the resistance value between the three phases A, B and C, whether they are equal, the larger the motor, the smaller the resistance value! But it cannot be 0 ohms for all three phases, unless it is a particularly large motor.

3. Check the bearings and fans. Generally, the motors are all replaced if they are wrapped. Sometimes the motors will be burned if the bearings are locked.

4. The no-load current of the motor is generally 10% to 50% of the rated current, and sometimes the no-load current of the motor is still zero.

5. When the rated current of the motor is running, it is running at full load, and the output power is basically 100%. The running current is small, indicating that the output power of the motor becomes small, and it is running under a light load.