Automatic series reactance starting three-phase motor circuit (2)

As shown in the figure, when the start button ST is pressed, the KM1 coil is closed, the main contact is connected to the reactor group L, and the motor M enters the reduced voltage starting state. At the same time, due to the closure of the KM1 auxiliary contact, the time relay KT is powered for timing. When the delay reaches the KT setting time, the KT contact is closed, the KM2 coil is energized, its normally closed contact cuts off the KM1 coil circuit, the KT coil also loses power one after another, and the KM2 normally open contact acts to protect itself. At this time, the main contact of KM2 is closed, the reactor L is short-circuited, and the motor starting process is completed.