Dalian motor shell will produce mechanical resonance in a certain frequency band during operation. At this time, the frequency hopping setting method of the frequency converter can be used. Generally, the frequency converter has a "frequency hopping" setting, which is used to set the frequency of motor resonance. When the frequency converter operates in this frequency band, it skips this frequency to avoid motor resonance. Open the motor housing and check that there is no burn mark on the coil surface. Remove the binding wire, weld the common contacts of the two groups of coils, measure the insulation resistance between the two windings, and it is confirmed that there is a short circuit. At this time, heat the coil with a hair dryer. After the enameled wire softens, turn the multimeter to the resistance gear and connect it between the starting and running windings. Then carefully separate the two groups of coils until the multimeter indicates infinite, and the short-circuit point is in this section of coil. Then check the insulation of this section of coil, treat it, and then dip it with insulating paint. After drying or drying, measure the starting winding resistance value to be 45 Ω, the running winding resistance value to be 20 Ω, and the sum of the two winding resistance values to be 65 Ω. Finally, restore the original state, connect the power supply, and the motor operates normally.