Chapter 4 Explanation of Functions
(3) Free V/f characteristic setting
The free V/f characteristic setting function allows you to set an arbitrary V/f characteristic by specifying the
voltages and frequencies (b100 to b113) for the seven points on the V/f characteristic curve.
The free V/f frequencies (1 to 7) set by this function must always be in the collating sequence of "1 ≤ 2 ≤ 3
≤ 4 ≤ 5 ≤ 6 ≤ 7".
Since all free V/f frequencies are set to 0 Hz as default (factory setting), specify their arbitrary values
(begin setting with free-setting V/f frequency (7)). (The inverter cannot operate with the free V/f
characteristic in the factory setting.)
Enabling the free V/f characteristic setting function disables the torque boost selection (A041/A241), base
frequency setting (A003/A203/A303), and maximum frequency setting (A004/A204/A304). (The inverter
assumes the value of free-setting V/f frequency (7) as the maximum frequency.)
Item Function code Data Description
Free-setting V/f frequency (7) b112 0.to 400.(Hz)
Free-setting V/f frequency (6) b110 0. to free-setting V/f frequency (7) (Hz)
Free-setting V/f frequency (5) b108 0. to free-setting V/f frequency (6) (Hz)
Free-setting V/f frequency (4) b106 0. to free-setting V/f frequency (5) (Hz)
Free-setting V/f frequency (3) b104 0. to free-setting V/f frequency (4) (Hz)
Free-setting V/f frequency (2) b102 0. to free-setting V/f frequency (3) (Hz)
Free-setting V/f frequency (1) b100 0. to free-setting V/f frequency (2) (Hz)
Setting of the output
frequency at each
breakpoint of the V/f
characteristic curve
Free-setting V/f voltage (7) b113
Free-setting V/f voltage (6) b111
Free-setting V/f voltage (5) b109
Free-setting V/f voltage (4) b107
Free-setting V/f voltage (3) b105
Free-setting V/f voltage (2) b103
Free-setting V/f voltage (1) b101
0.0 to 800.0(V)
Setting of the output
voltage at each
breakpoint of the V/f
characteristic curve (*1)
(Example)
f1 f2 f3 f4 f5 f6 f7
0
V2,V3
V1
V5
V6
V7
V4
Output volt
Output frequency (Hz)
age (V)
*1 Even if 800 V is set as a free-setting V/f voltage (1 to 7), the inverter output voltage cannot exceed the
inverter input voltage or that specified by the AVR voltage select.
Carefully note that selecting an inappropriate control system (V/f characteristic) may result in
overcurrent during motor acceleration or deceleration or vibration of the motor or other machine driven
by the inverter.
0 f6 f7
V6
V7
Voltage that can be output by the
inverter or that was specified by
the AVR voltage select
Output frequency (Hz)
Output voltage (V)
4 - 17