The overload relay is a protective device used to protect the motor, which plays the role of protection against motor overload shutdown.

When the motor is running, the motor may be damaged by abnormal conditions such as overload or short circuit, or even safety accidents such as fire, so it is necessary to install some protective devices to protect the safe operation of the motor.

The overload relay is one of the protection devices. Its main working principle is: when the motor load is too large, the overload relay receives a signal from the motor and determines whether it is necessary to cut off the power by comparing the actual load with the rated load.

In addition to overload protection, the overload relay can also implement short circuit protection, phase loss protection and other functions to effectively protect the safe operation of the motor.

It can be said that the overload relay is a very important protection device and plays an essential role in the safe operation of the motor system. Therefore, when using the motor, we must pay attention to the installation and correct setting of the overload relay to ensure that the motor will operate within a safe load range.