Why do we use star to star connection in motor?

Answer 1

In a high voltage installation, with the same power, current drawn is small compared to those in low voltage. However it requires a thicker insulation, thus cost of insulation is significant compared to the conductor cost.

By using a star connected winding, the insulation voltage required is equal to line to neutral connection, otherwise if it is connected in delta the insulation rating has to be provided for a line to line connection.

Despite having a higher current, the total cost is still lower compared to using a higher insulation rating.

Answer 2

Wye vs. Delta connections are site specific. I often see high voltage sides of Transformers connected in delta - specifically distribution level step down transformers are very often Delta/Wye. A wye connection provides a ground connection, so connected conductors only need be insulated for L-N voltages (if solidly grounded), instead of L-L voltages for a typical delta connection. There are other reasons that come into play as well.

Answer 3

Gently we are using star delta starter for hiegh rating motors,,in star connection the line current is equal to the phase current and incase delta connection the line and phase voltages are equal,,at starting the current will be maximum.

Answer 4

hot motor are connected in star because it deals with the voltage in case small Power system, which the voltz could either drop or rise.

Answer 5

becoz if we connect it in delta,it draws much current,,,,so we connect in star to draw less current