The noise generated by the motor itself: suddenly the sound is abnormal during operation. Check whether the motor runs in a single phase: one is that the power supply is broken, and the other is that the motor is broken. This situation must be stopped, otherwise it is easy to burn the motor; Phase current should be detected, generally not more than 10%. UNIDIDIDIDIDIDIDID: First, the power grid voltage is unbalanced; the other is that the motor stator winding has an instant short circuit; the third is that the fixed and the rotor is uneven; the fourth is that the rotor has a broken bar and a thin strip phenomenon. Electric failure, take measures as soon as possible.