The magnetic starter consists of a steel stamping housing, a steel bottom plate, an AC contactor, a thermal relay and a corresponding wiring, which should be fitted with a start stop button switch and a hand-controlled signal cable to be properly connected. When the Start button is pressed, the AC contactor coil in the magnetic starter is electrically powered, the armature drives the contact group to be closed, the General Electric (general Motor) power supply, and the auxiliary contact point self-locking. When the stop button is pressed, the internal AC contactor coil loses power, the contact point is disconnected, and the electrical power lock is cut off. General CCS standards are greater than 0.5KW motor starting must use magnetic starter, other classification society 1kW as the starting point, which is the norm. AC 50Hz, voltage to 660V, current to 95A in the circuit as the control of three-phase squirrel-cage motor start, stop and reverse operation of the use, with small size, easy installation features. The magnetic starter is used as the control AC motor to start, stop and overload protection. The magnetic starter is composed of an AC contactor, a thermal overload relay, and is fitted in a metal protective enclosure with a general dust-proof capability, and an easy to operate button. Thermal overload relay has the function of temperature compensation and automatic and manual resetting, which can adjust the current setting of the plate dynamic adjusting button. The thermal overload relay is also provided with a fault-phase protection mechanism, which can cut off the power of the motor when the motor is running.