Measure the good or bad of the three phase motor.
1, find the star connection to disassemble it, the three phase windings should have 6 heads, and the small motor of the three joint can not measure the interphase insulation resistance.
2, measure whether the winding of each phase is broken, and the circuit breaker will be broken.
3, measurement of interphase insulation resistance, the resistance is less than 500 billion Europe has a problem, generally is caused by moisture, after drying, then measured.
4, measuring the insulation resistance of each phase winding, the same resistance should be greater than 500 billion Europe, if the drying is still less than 500 billion European motor will be broken.