Omron RX - Constant Torque Characteristics (VC)

4-22
4-2 Function Mode
4
Functions
Constant Torque Characteristics (VC)
Output voltage is proportional to output frequency.
While proportional from 0 Hz to base frequency, the output voltage is constant from base to
maximum frequencies.
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.
Period a: Provides constant torque characteristics within a range from 0 Hz to 10% of the base
frequency.
(Example) If the base frequency is 50 Hz, the Inverter provides constant torque
characteristics within a range from 0 to 5 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 characteristics within a range from the base frequency to the
maximum frequency.
Free V/f Setting
•You can set desired V/f characteristics by setting 7 points of voltage and frequency. (b100 to b113)
•The free V/f frequencies should always be 1  2  3  4  5  6  7.
All the default settings are 0 Hz. You must set Free V/f setting 7 first. (Operation is disabled by
factory default.)
•If the free V/f setting is enabled, the functions of torque boost A041/A241, base frequency A003/
A203/A303, and maximum frequency A004/A204/A304 are disabled. (Free V/f frequency 7 is
regarded as the maximum frequency.)
0
Output voltage
(100%)
Base frequency
Output
frequency (Hz)
Max. frequency
0
Output
voltage
(100%)
Base
frequency
Output
frequency (Hz)
Max.
frequency
VC
VP(f )
10% of base
frequency
1.7
a
b
c
Parameter No. Function name Data Description Default setting Unit
b100 Free V/f frequency 1 0. to Free V/f frequency 2
Set frequencies for
each break point.
0Hz
b102 Free V/f frequency 2 0. to Free V/f frequency 3
b104 Free V/f frequency 3 0. to Free V/f frequency 4
b106 Free V/f frequency 4 0. to Free V/f frequency 5
b108 Free V/f frequency 5 0. to Free V/f frequency 6
b110 Free V/f frequency 6 0. to Free V/f frequency 7
b112 Free V/f frequency 7 0. to 400.