Automatic series resistance starting three-phase motor circuit (1)

As shown in the figure is an automatic series resistor starting three-phase motor circuit. Press the start button ST, the AC contactor 1KM and the time relay KT are electrically activated, the normally open contact 1KM is closed and self-locking, the main contact 1KM is activated, and the motor stator winding is connected in series to the resistor group R, and the motor M is started by reducing the voltage. At the same time KT clocked the time. After the KT delay reaches the setting time, the KT normally open delay closing contact is closed, the 2KM coil is energized, and its main contact 2KM acts, short-circuiting the resistor R, and the motor stator winding is put into rated voltage operation.