The Function of an AC Contactor

In the electrical system of the laser welding machine, the AC contactor is a crucial executive component. Its main function is to control the on-off of the laser source, power module, drive device, and peripheral control unit, thereby ensuring the electrical safety and operational reliability of the equipment during startup, operation, and shutdown. The AC contactor generates electromagnetic attraction through the coil excitation, enabling the main contacts to close or open, allowing the high-power circuit to achieve stable switching capability. 
In the laser light source power module, the AC contactor is used to control the main power input of the rectifier unit, inverter unit and cooling system. This component can withstand the high surge current during the operation of the laser and keep the contact resistance within the allowable range, avoiding power fluctuations due to poor contact, thereby protecting the pump source, optical components and power control circuit. 
In terms of the control system, the AC contactor forms an interlock relationship with the overload protector, thermal relay, emergency stop unit and programmable logic controller (PLC). This interlock structure enables overload tripping, fault power-off and safe linkage control, ensuring that the laser welding machine can promptly cut off the main power supply when there is an electrical anomaly, preventing the high-power laser from being damaged due to continuous power supply or thermal instability. 
In the drive mechanism section, AC contactors are used to control the external power supply channels of the servo motor or stepper motor. Through coordinated control logic, the start and stop management of the motion axes can be achieved, enabling the welding path, workpiece positioning, and oscillation system to operate under the controlled power supply conditions. The electrical capacity of this component and the durability of the contacts directly affect the long-term stability of the equipment. 
In addition, the contactor has replaceability and diagnostic capabilities in system maintenance. Its mechanical lifespan, coil insulation grade, contact withstand voltage value, and rated working current are all key parameters that can be used to assess the operating status of the equipment and establish maintenance cycles. By monitoring the action noise, temperature rise, and holding stability of the contactor, it is possible to determine whether there is contact wear or abnormal electrical load in the main circuit. 
The communication interface in the laser welding machine plays a crucial role in tasks such as power switching, safety interlock, motion control power supply management, and fault protection. The performance of this component directly affects the electrical safety, output stability, and overall operational reliability of the laser welding machine. It is an indispensable basic electrical component in the equipment.