... standard,obtained CCC,CE,CQC 2:years of motors history,high quality 3:explosion-proof 4:Protection class:IP55 Specifications & ... IEC60034 standard. Specifications & FeaturesRated voltage: 380V, 660V, 380V/660V,Rated frequency: 50HzDuty: Continuous (S1). Insulation class: FProtection degree: IP55Cooling method: ... humidity should be less than 90%. YB2 three phase induction motor (ISO9001 CE CCC CQC)