Star Delta

Most induction motors are started directly on line, but when very large motors are started that way, they cause a disturbance of voltage on the supply lines due to large starting current surges. To limit the starting current surge, large induction motors are started at reduced voltage and then have full supply voltage reconnected when they run up to near rotated speed. Two methods are used for reduction of starting voltage are star delta starting and auto transformer stating.


  • Star-Delta starters are widely used due to their relatively low price

  • There are no limits to the number of times they can be operated

  • The components require very little space.

  • The starting current is reduced to approximately one-third.


  •    Long Life.

  •    Superior Performance.

  •    Easy Maintenance.
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