Electric motor's failure recognizing method, involves producing induced voltage through switching-off of motor, and measuring and examining induced voltage whether induced voltage falls below given threshold value in switching-off phase

摘要

The method involves switching-off an electric motor (3) for a short-time during an operation. An induced voltage is produced through the switching-off of the motor and is measured and examined whether the induced voltage falls below a given threshold value in a switching-off phase. The electric motor is re-started before the motor produces a lag voltage, where the electric motor is switched-off for a period of less than 1 millisecond. An independent claim is also included for a device for recognizing the failure of an electric motor.