Star Delta Starter
The Star Delta Starter is a very common type of starter and is used extensively as compared to the other type of starting methods of the induction motor. A star delta is used for a cage motor designed to run normally on the delta connected stater winding.
Motor Starting Characteristics of Star-Delta Starter:
- Available starting current: 33% Full Load Current.
- Peak starting current: 1.3 to 2.6 Full Load Current.
- Peak starting torque: 33% Full Load Torque.
Advantages of Star-Delta starter:
- The operation of the star-delta method is simple and rugged.
- It is relatively cheap compared to other reduced voltage methods.
- Good Torque/Current Performance.
- It draws 2 times starting current of the full load ampere of the motor connected.
Features of star-delta starting
- For low- to high-power three-phase motors.
- Reduced starting current
- Six connection cables.
- Reduced starting torque.
- Current peak on changeover from star to delta.
- Mechanical load on changeover from star to delta.
Application of Star-Delta Starter:
- The star-delta method is usually only applied to low to medium voltage and light starting Torque motors.
- The received starting current is about 30 % of the starting current during direct on line start and the starting torque is reduced to about 25 % of the torque available at a D.O.L start. This starting method only works when the application is light loaded during the start. If the motor is too heavily loaded, there will not be enough torque to accelerate the motor up to speed before switching over to the delta position.