Relays and contactors in the circuit and role differences

Difference is essentially different from the loads, the large current capacity contactor, is a relay of small, there are differences between the primary circuit with a contactor, a relay control circuit. The electrical control circuit, the relay is a logical part of the operative part of the contactor, relay circuit design process in accordance with both the requirements pulsing the main contacts of the contactor is electric transformer, according to the circuit design process can be required to make the contactor remain the main contact to achieve if the measurement part likened to the human mcb circuit breaker the logical part is the muscle, and the contactor can be likened to the bone, they can control circuits together with the sub-switch. contactor is a use to control the motor starts and stops an electrical device, larger capacity, has a strong ability interrupter, belonging to one device. The relay is part of a relay device is a secondary device, Voltage stabilizer different combinations to achieve the primary equipment for control, protection, monitoring, and so on. There used to measure the current (voltage), impedance relay contact capacity and increasing for increasing the number of intermediate relay contact pair is used to obtain the necessary delay time relay, check for the same period in parallel or contemporaneous period reclosing air switch relay scientific name should be the circuit breaker can be used to cut off a larger current, short circuit occurs when the line can quickly trip protection devices, but not suitable for frequent operation. Contactor on the current strong cutting capacity without air switch, suitable for frequent operation, however.