Why motor is connected in star connection first in star delta starter?

To use a star delta starter, the motor must be a three phase six wire motor. The extra wires out are the wires that are usually terminated in the motor housing as the star point. The starter, when energized, brings the star contactor in and closes the star point coil ends. An external timer times out after the motor gets up to speed in the star connection and drops the star contactor and closes the delta contactor. When in the delta connection the motor coils are then paralleled to allow the motor to run at full voltage.