A surge protector, also known as a lightning arrester, is an electronic device that provides safety protection for various electronic equipment, instruments, and communication lines. When the electrical circuit or communication line suddenly produces a peak current or voltage due to external interference, the surge protector can switch on the shunt in a very short time, so as to avoid the damage of the surge to other equipment in the circuit.

Relay is an electrical control device, its core role is to use small current to control the operation of large current, equivalent to an automatic switch. In the circuit has automatic regulation, safety protection, conversion circuit and other functions. When enough current flows through the coil, the generated magnetic field will attract the armature, making the moving contact and the static contact close or break, so as to achieve the circuit switching control.

Motor Protection Circuit Breaker (MPCB) is suitable for the alternating voltage to 690V, the eloctric curront 1 to in the 80A electric circuit, takes three phase mouse cageasychronous electric motor overload, breaks, short-circuit protection and not frequent starting control uses, my serve as the distribution line protection and the not frequent, load transformation, but also may do isolates the use.