Core Functions：
Remote Control: Indirectly controls the main circuit's on/off state via signals triggered by buttons, PLCs, etc.
Overload/Short Circuit Coordination: Works with circuit breakers and thermal relays to protect the load.
Frequent Switching: Suitable for high-frequency (e.g., several times per minute) circuit switching, with a lifespan far exceeding that of ordinary switches.
Basic Structure：
Electromagnetic System: Coil + iron core, generating magnetic force to close the contacts when energized.
Contact System:
Main Contacts: High current (tens to thousands of A), connected to the load's main circuit.
Auxiliary Contacts: Low current (several A), connected to control circuits (e.g., self-locking, interlocking).
Arc Extinguishing Device: High-power contactors have a built-in arc extinguishing chamber to prevent arc erosion when contacts open.
