Broken rotor bars refer to the copper bars in the rotor of squirrel-cage asynchronous motor broken due to the action of electric torque (starting torque, braking torque) or human action. The rotor of squirrel-cage asynchronous motor is not wound, but is made of several cast copper bars welded between two cast copper rings. Copper bus can bear more current than copper wire and is easy to install, so squirrel-cage asynchronous motor is more widely used than wound asynchronous motor.

If the rotor is broken, it is necessary to disassemble the motor, take out the rotor and measure the resistance of each copper bar one by one. Needless to say, there must be something wrong with the copper bar with extremely large resistance.

Broken rotor bars will not affect the operation of the motor in a short time, but the motor will vibrate, because the broken rotor bars are unevenly stressed, the rotor will swing to a certain extent, and the motor will generate more heat, which will definitely be bad for the motor in a long time!