How to judge the good or bad of motor

Summary of how to determine the quality of three-phase asynchronous motor coil, what instrument inspection to use?:

1 trillion ohm meter; can be used to measure insulation resistance between motor and relative phase, and can not be less than 500 billion ohm. Use 500V megohmmeter to measure the insulation resistance of more than 0.5M that is good is lower than that of the 0.5M motor is broken, but this is only appearance for interturn short circuit breakdown phase only open inspection.

20 thousand meter; used to check the measurement of motor coil breaking

3. Wheatstone bridge; accurate measurement of coil resistance, you can know whether the resistance of each phase coil is close, especially after re winding

The fault of the motor is nothing more than two pieces: machinery and electricity.

Mechanical aspects:

1, bearing is lack of oil or damage,

2, whether the end cover "running coat", bearing "running inside sleeve"?"

The main aspects of electricity are:

1. Whether the insulation resistance is qualified

2, three phase DC resistance is qualified, with double arm bridge measurement.

3. Whether the rotor is broken or not, the DC resistance of the motor is an important basis for judging the motor.