1. The essential difference between relay and contactor is that the load is different, the contactor with large current capacity, and the relay is the small one. The contactor used in the main circuit is different, and the relay for control circuit is different.

2. The function of contactor is to turn on and break the current signal with large amount, and drive the power equipment such as motor;

3. Relay is used to convert signals, and the interface between different voltage levels of equipment to control signals, and its contact bearing capacity is generally small, which is used to drive electrical components such as contactors.