本系列电动机外形及安装尺寸、绝缘等级、防护等级、冷却方法、结构及安装型式、使用条件、额定电压、额定频率等与 Y 系列（ IP44 ）电动机相同，适用于需要逐级调速的各种传动机构。
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
