Star Delta Starter Practically

A star Delta starter is used to reduce the starting current in the induction machine so that winding do not over heat and burn out during starting as a starting current is very high.
 It’s theoretical background is very well explained in  engineering textbook of B. L. Thereza,  but practically how this connection Is realised in an industry is missing in the book.
Have a look for improved simulation of Star delta Connection of Induction Machine.