Three-phase motor Yanbian delta-shaped step-down starting circuit

Press the start button ST, the 1KM coil is electrically activated and self-protected. At the same time, the 3KM and time relay KT coils are energized, and the motor windings are connected into a Yanbian triangle to reduce the voltage and start. After the setting time of Kt reaches, the delayed normally closed contact opens, causing the 3KM coil to lose power and release, and its normally auxiliary closed contact closes. At the same time, the delayed closing normally open contact of KT is closed, and the 2KM coil is energized and self-locking. The main contact of 3KM is released, the main contact of 2KM is closed, the motor winding is converted from Yanbian delta to delta connection, starting is completed and operation begins. This circuit is suitable for occasions requiring large starting torque.