Motor overcurrent protection circuit

Today we introduce the overcurrent protection circuit of the motor. When the motor starts, press the lock button SBi once. After the start is completed (after the motor speed is stable), press SBi again, and the protection circuit will start working. For motors with a short starting time (such as a few seconds), SBi can also use ordinary buttons, as long as the SBi is pressed during the starting process.

When the motor is running normally, the secondary induced potential of the current transformers TAi~TA3 is small and not enough to trigger the thyristor V. As shown in the figure below.