△-Y conversion two-speed motor control circuit

(1) Low-speed operation: Turn the switch SA to the "low-speed position", contactor KM1 is electrically activated, the outlet terminals of the motor stator windings Ul, Vl, and Wl
are connected to the power supply, and the motor stator windings are connected in a triangle to run at low speed.
    (2) During high-speed operation, turn the switch SA to the "high-speed" position, the time relay KT coil is energized, the KT instantaneous contact is closed, and the KM]
coil is energized. KM1 movable contact is disconnected, KJVI1 main contact is closed, and the motor winding is first connected into a triangle for low-speed starting. After KT - a certain
delay, the moving-off contact of the time relay KT is opened, the moving-making contact is closed, the contactor KMI coil is de-energized and released, and the contactor KM2 and
KM3 coils are electrically activated, causing the motor stator winding to be The main contacts of KM2 and KM3 are changed into double star shapes and run at high speed.