The thermal relay generates heat from the current flowing into the heat element; the bimetal piece with different expansion coefficients is deformed, and when the deformation reaches a certain distance, the link is pushed to cause the control circuit to be disconnected, thereby causing the contactor to lose power. The main circuit is disconnected to achieve overload protection of the motor.

effect:

When using a thermal relay to protect the motor from overload, connect the thermal element to the stator winding of the motor, connect the normally closed contact of the thermal relay in series with the control circuit of the electromagnetic coil of the AC contactor, and adjust the setting current adjustment knob to make the person The font lever is at an appropriate distance from the push rod. When the motor works normally, the current passing through the heat element is the rated current of the motor, the heat element heats up, and the bimetal is bent after being heated, so that the push rod just touches the herringbone lever, and cannot push the chevron lever. The normally closed contact is in a closed state, the AC contactor remains closed, and the motor operates normally.