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Switching with motor contactor

The motor cable may only be switched with the power cut, otherwise problems such as burnt-out contactor contacts, overvoltage or overcurrent shut-off may occur. To ensure currentless switching, the contacts of the motor contactor must be closed before enabling the power stage. In the opposite case the contacts must remain closed until the power stage has been switched off. This can be achieved by implementing the corresponding safety periods for switching of the motor contactor into the control sequence of the machine or by using the special "ENMO" software function of the drive controller.

A power contactor in the motor supply line can be directly controlled by the drive controller via parameter P 0125 MPRO_OUTPUT_FS_MOTOR_BRAKE = BRAKE. The timer P 0148 MPRO_DRVCOM_ENMO_Ti defines the on-and-off delay of the power contactor. Based on the time delay, the reference value is applied after the power contactor is active. If the power stage is switched off, the power contactor isolates the motor from the controller.

NOTE: The P 0148 MPRO_DRVCOM_ENMO_Ti timer time should allow additional times for typical contactor bounce. They may be several hundred ms, depending on contactor.