The YD series variable pole multi speed three-phase asynchronous motor has the same appearance and installation dimensions, insulation level, protection level, cooling method, structure and installation type, usage conditions, rated voltage, rated frequency, etc. as the Y series (IP44) motor, and is suitable for various transmission structures that require stepwise speed regulation. At an altitude not exceeding 1000m and an ambient air temperature not exceeding 40℃The motor can operate at rated speed.