What are the functions of communication contactors?

The core function of an AC contactor is to achieve frequent switching of high-power circuits and provide low-voltage protection function. It is a crucial component in power automatic control systems, with specific functions and application scenarios as follows:

1. Core functions

Frequent on/off of main circuit: This is its core function, specifically used for high-frequency connection and disconnection of main circuits carrying large currents (such as power circuits of motors and high-power appliances). Compared with manual switches, it is more suitable for high-frequency operation, with a rated current of up to 800A, which can meet the requirements of large loads.

Remote control: The high current main circuit can be indirectly driven through a small current control circuit to achieve remote operation, avoiding close contact with high voltage and strong electricity by operators and improving operational safety.

Voltage loss/undervoltage protection: When the voltage of the power supply line is too low or the power is cut off, the contactor will automatically release the contacts to disconnect the main circuit. After the power is restored, it will not start on its own, which can avoid equipment damage due to abnormal voltage and prevent accidents from occurring.

Cooperate to achieve logical control: By using the built-in normally open and normally closed auxiliary contacts, it can cooperate with relays to achieve various control logics such as timing, self-locking, interlocking, etc., meeting the control requirements of automation circuits.

2. Common application scenarios

The characteristic of large control capacity of AC contactors makes them widely used in various power load scenarios:

The core control object is various types of electric motors, used to achieve the start stop and forward/reverse control of the motors;

It can also control other electrical loads, such as electric heating equipment, lighting systems, welding machines, capacitor banks, high-power commercial appliances, etc;

It is essential in scenarios where frequent start stop equipment is required, such as industrial automation production lines, elevators, pump stations, injection molding machines, etc.