本系列電動機外形及安裝尺寸、絕緣等級、防護等級、冷卻方法、結構及安裝型式、使用條件、額定電壓、額定頻率等與 Y 系列（ IP44 ）電動機相同，適用于需要逐級調速的各種傳動機構。

YD series change-pole multi-speed three-phase induction motor's, the dimensions of mounting and contour, insulation class, protection grade, cooling form, structure and mounting type, condition for use, rated voltage, and rated frequency of this series motors are all the same as those of Y series(IP44) motors, They can apply to various transmission mechanism, the speed of which needs