... speed sensorless vector control (SVC) 12.Protection funtion: Input open-phase protection,over-current protection,overload protection,undervoltage protection ... Humidity :20~90% RH( Non-condensing)3.Indoor places free from direct exposure to sunlight, dust, corrosive gas, flammable ... driving and speeding control of AC asynchronous motor. power inverter with vector control output frequency 0.00hz--600hz