Constant Torque Characteristics (Vc) - Omron SYSDRIVE RX Series User Manual

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 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 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.)
Output voltage
(100%)
0
Base frequency
Output
voltage
(100%)
1.7
VP(f )
VC
0
10% of base
Base
frequency
frequency
a c
b
4-2 Function Mode
Output
frequency (Hz)
Max. frequency
Output
frequency (Hz)
Max.
frequency
4
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