Star-Delta Starter #electrical #electricity #starter #electrician #engineer #engineering #stardelta

追加: 2026-06-02

[00:00:00]Welcome to Mentor 1. In this video, let's discuss about working principle and advantages of star delta starter.

[00:00:10]A star delta starter is a motor starting method used to reduce the high starting current of large three phase induction motors. It starts the motor in star connection and automatically changes to delta connection after preset time delay for normal operations.

[00:00:31]Single line diagram.

[00:00:33]The power supply flows through the MCCB, main contactor, start contactor, delta contactor, and overload relay to the motor.

[00:00:45]Proper interlocking ensures that star and delta contactors do not operate simultaneously.

[00:00:53]Working principle.

[00:00:55]Initially, motor starts in star mode.

[00:00:59]Voltage across each winding becomes VL by root three.

[00:01:05]Starting current reduces significantly.

[00:01:08]It helps to avoid voltage dip in the system.

[00:01:12]After a preset timer delay, motor shifts to delta mode.

[00:01:18]Full line voltage is applied to motor winding.

[00:01:22]Motor runs in full power torque.

[00:01:25]Advantages of star delta starter.

[00:01:29]It reduces starting current. It reduces voltage dip in the system.

[00:01:34]Improves motor starting performance.

[00:01:38]It is suitable for medium and large motors.

[00:01:42]An important point to note.

[00:01:45]Starting current in star delta starter is approximately 1 by 3 of DOL starting current, making it ideal for large motor applications.

[00:01:58]Common applications of star delta starters are pumps, compressors, blowers, industrial motors, HVAC system.

[00:02:09]Thank you.