YD series change-pole multi-speed three phase asynchronous motor is a derivative series of Y series motor. YD series change-pole multi-speed motors change the pole number of the motor by changing the connection method of the stator winding. So that the motor or two sets of winding can obtain two or more kinds of speed. This series of motor fully comply with the Technical Conditions for YD Series (IP44) Pole Changing Multi speed Three phase Asynchronous Motors