electromagnetic starter (electromagnetic starter), a combination of electromagnetic contactor and overload protection element. Also called magnetic starter. Because it directly adds the grid voltage to the stator winding of the motor and makes the motor start at full voltage, it is also called the direct starter. Electromagnetic starter is often used when the power grid and load do not require special starting characteristics. It is not only convenient for operation and control, but also has overload and voltage loss protection function.

Overload protection means that when the load of the motor exceeds its rated load and exceeds a certain allowable time, the electromagnetic starter can automatically break the motor power supply. Voltage loss protection electromagnetic starter is switched on, the motor start and put into normal operation, you have a power failure, electromagnetic starter can automatically cut off the circuit, to prevent the power to electric motor self starting, so as to avoid equipment damage and injuries.

Electromagnetic starter is divided into two kinds of irreversible and reversible. The former is used for starting induction motors without inversion; the latter is used for induction motors which need reversal. Button operation for electromagnetic starter. The reversible electromagnetic starter has two buttons, "start" and "stop"; the reversible electromagnetic starter has 3 buttons: "forward", "reverse" and "stop".

In order to prevent the normal control and reverse control contactor contactor starter and reversible electric power, so that the short circuit in the control circuit is generally equipped with electrical interlock, sometimes adding mechanical interlock, to ensure that only when a contactor starter is in the open position, another possible contactor power moves. While the motor is running in one direction only.