For the motor, its life span is very limited, how can we better protect him and extend its service life.

Use the current transformer to measure whether the three-phase zero sequence of the incoming line of the motor is zero. It is generally used for motors with large power. The specific method is: select the appropriate current transformer according to the power of the motor and install it at the incoming end of the motor control box.

When using temperature to protect the motor, the internal thermal device is used for protection. When the temperature is too high, a signal is given to be protected by an external control loop. Or use thermal resistance, thermoelectric corner measuring the temperature of the motor through the temperature controller to give an overheat signal, thereby protecting the motor.

There are two main ways to protect the motor, one is to use the internal thermal device for protection, and the other is to select the appropriate current transformer according to the motor power and install it at the incoming end of the motor control box. All methods are feasible.