The star-delta starter effectively reduces starting current by utilizing the star configuration during startup, which lowers the voltage across the motor windings. This approach not only protects the motor and electrical system but also contributes to more efficient operation in various industrial applications..
Starting Phase: The motor is initially connected in the star configuration, which limits the voltage and thus the starting current. This phase allows the motor to accelerate smoothly.
When the motor starts, the windings are connected in the star configuration. This arrangement effectively divides the line voltage by √3 (approximately 1.732), reducing the voltage across each winding to about 58% of the full line voltage.
Running Phase: After a predetermined time or when the motor reaches about 70-80% of its full speed, the connection switches to delta, allowing the motor to operate at full voltage and torque.
