4-2 Function Mode „ Control Method (V/f Characteristics) Constant Torque Characteristics (VC) •Ouput voltage is proportional to output frequency. While proportional from 0 Hz to base frequency, the output voltage is constant from base to maximum frequencies regardless of the frequency. Output voltage (100%) Output frequency (Hz) 4 0 Base frequency (A003/A203) Max. frequency (A004/A204) Reduced Torque Characteristics (VP 1.7th power) •Suitable for a fan or pump that does not require large torque in a low speed range. These provide high efficiency, reduced noise and vibration, owing to reduced output voltage in a low speed range.
Functions Output voltage (100%) Output frequency (Hz) 0 Base frequency (A003/A203) Max. frequency (A004/A204) Special Reduced Torque Characteristics (Special VP) •Suitable for a fan or pump that requires torque in a low speed range. These have VC characteristics only for low deceleration in reduced torque characteristics. Output voltage (100%) VC Output frequency (Hz) 10% of base frequency 0 Base frequency (A003/A203) Max. frequency (A004/A204) a b c Period a: Provides constant torque characteristics (VC) within a range from 0 Hz to 10% of the base frequency. (Example) If the base frequency is 60 Hz, the Inverter provides constant torque characteristics within a range from 0 to 6 Hz.
Period b: Provides reduced torque characteristics within a range from 10% to 100% of the base frequency. The Inverter outputs voltage based on a curve of the 1.7th power of the frequency. Period c: Provides constant voltage within a range from the base frequency to the maximum frequency. 4-13 VP (1.7th power of VP) VP (1.7th power)