Y2D Series pole-changing multi-speed phase asynchronous motors are one of the main derivatives of the same type. They have step changes of rotational speed to meet the requirements fo load character, so that the obtain the advantages of suitable matching of power and simplify speed changing systems. For this reasons they are worth calling ideal motive power for saving energy consumption in mechanical systems. They are widely used in such insustrial and agricultural departments, as machine tools, mining, metallurgy, spinning and weaving, printing and dyeing, chemical industry, and agricultural machinery, etc.