Standard design data Standard GB755 IEC Voltage 380V (400-450mm), 660V (500-560mm) Cooling method IC416 (independent axial fan, or centrifugal fan) Independent fan voltage three-phase, 380V Frame size 400-560mm Rated frequency 50HZ Insulation class F Installation form IMB3 Working method S3-40% for lifting and metallurgy Protection class IP54 Overload multiple At rated voltage and rated frequency, 150% rated current is allowed to overload for 1 minute Altitude does not exceed 1000m