The three-phase asynchronous motor of the hydraulic waste paper baler can be started with direct start and reduced voltage start. Direct starting is a simple, reliable and economical starting method, but the starting current of the motor is 4/7 times the rated current.
Excessive starting current will cause a significant drop in the grid voltage on the one hand, and directly affect the normal operation of other motors and electrical equipment working on the same grid; on the other hand, the frequent starting of the motor will cause serious heat, accelerate the aging of the coil, and shorten the life of the motor. Only motors with small capacity are allowed to be started directly, and cage asynchronous motors with larger capacity generally start with a step-down starting method due to the larger starting current. Step-down starting refers to the use of starting equipment to properly reduce the voltage and add it to the stator winding of the motor to start. After the motor is started and run, the voltage is restored to the rated value for normal operation. Since the current decreases with the decrease of the voltage, the step-down starting achieves the purpose of reducing the starting current. ?
But at the same time, since the motor torque is proportional to the square of the voltage, the reduced voltage starting will also cause the motor's starting torque to be greatly reduced. Therefore, reduced voltage starting needs to start under no load or light load.