Main and tail connection: three windings, then three - phase power supply. The winding schematic is triangular;

Y connection: three windings are connected together as the neutral point, and three tails are connected with three-phase power.

Air current connection has the advantage of high output power, high starting torque, and high starting current.

The Y connection has the advantage of low starting current, but low power and torque.

Output power of the same motor: current is 3 times of current Y.