Squirrel cage motor forward and reverse control circuit diagram

Squirrel cage motor forward and reverse control circuit diagram

By swapping any two wires connecting the motor to the power supply, the motor can be reversed.

Two contactors are needed to achieve this requirement. When the forward contactor is working, the motor rotates forward; when the reverse contactor is working, swap any two wires connecting the motor to the power supply, and the motor will reverse.

Forward and reverse control circuit:

Analysis of the forward and reverse control example of squirrel cage asynchronous motor

During the production process, the production machinery that we maintenance electricians often come into contact with requires moving parts to frequently run forward and reverse.

The following two control circuits are introduced for analysis one by one. In Figure a, a control circuit with double interlocking of buttons and contactors is adopted. On the basis of using the normally closed auxiliary contacts of the forward and reverse contactors for interlocking, composite buttons SB2 and SB3 are added for interlocking protection. In this circuit, even if two start buttons are connected at the same time, the forward and reverse contactors cannot be powered. In addition, when a composite button is used, after the motor runs forward, it is not necessary to press the stop button SB1 first, and the reverse start button can be directly pressed to make the motor run in the reverse direction.

In the actual production process, if the operation is frequent, the forward and reverse contactors may still be connected at the same time. In order to avoid the forward and reverse contactors being attracted at the same time, an intermediate relay kA can be added to the control circuit to extend the conversion process. As shown in Figure b. In other occasions, a special mechanical interlocking contactor can be used as appropriate.

The above is a summary of my experience in the course of my work. I hope it will be helpful to new electricians in the industry so that we can learn together.