They are designed to connect directly to high-current power devices.
Relays and contactors have similar purposes and working principles. However, the difference of contactors from relays is that they can switch more than 15 amps and have an operating power above a certain kW. Contactors come in forms with varying capacities and characteristics. Unlike a circuit breaker, contactors are not intended to interrupt short-circuit current. These devices can have a breaking current of a few amperes or thousands of amperes. They are also very diverse devices in terms of physical size and volume.
The device has two contacts, main and auxiliary.
Main Contacts: These contacts are used to open and close the large current carrying the main power circuit. Main contacts are usually designed to handle large currents safely.
Auxiliary Contacts: These contacts are used to monitor the status of the device, transmit signals or perform control operations. Auxiliary contacts are usually used for lower power signaling circuits. Cores, coils, contacts, pallets and copper rings are also components of the device. Different types of devices for different purposes may have different contents.