... load soft start, soft stop and operation process of asynchronous motors of exchange current 50Hz, rated voltage 660V ... oil pumps. 4.Technical Parameters Rated input featureAC 380V, AC 660V, AC 1140V;50Hz~60HzVoltage fluctuation: ±15%, frequency fluctuation: ... relay outputDisplayDisplay screenSetting frequency, output frequency, current, power, motor speed, load rate, input and output torque, etc.Fault ...