YD series is one of the main derived series of Y series, a national unified designed latest product in China and a replacement type for the JOD2 series it can change speed easily. The speed of this series motor can be changed step by step according to the requirements of load characteristics, thereby reaching the aims of economizing on electricity and simplifying the system of speed variation. This series of motor has great starting torque and Iow noise and vibration, and its mounting dimensions are complied with the standard of the International Electrotechnical Commission(IEC), it has a fairly good interchangeabitity as compared with the similar productsof the same kind so that it is easy to maintain and used widely in the industrial departments of Machine tools, chemical industry , textile, metallurgy and mine, etc. The degree of protection of the motor is of IP44, cooling mode is IcO141, and B-class insulation is adopted, the mode of rating is continuous running.