4-22
Control system (V/f Characteristic)
Set V/f (output voltage/output frequency) characteristic.
To change 1
st
/2
nd
control system (V/f characteristic), set
08(SET) to an intelligent input terminal and switch it ON.
Function code
Data
V/f characteristic
00
Constant torque characteristic(VC)
01
Reduced torque characteristic(VP1.7power)
A044/A244
02
Free setting V/f characteristic
(1) Constant torque characteristic (VC)
Output voltage outputs proportionally to the output frequency.
Output voltage outputs proportionally from 0 to the base frequency, but the output voltage from the base
frequency to the maximum frequency is constant regardless of frequency.
(2) Reduced torque characteristic (VP1.7 power)
This characteristic can be used when a large starting torque isn’t required.
At low speeds, it can cause improvement of efficiency, low noise and low vibration because of lowering the
output voltage.
V/f characteristic is as follows.
Period :The limit from 0 to 10% of base frequency is the constant characteristic.
(Example) If the base frequency is 60Hz, the limit from 0 to 6Hz is constant characteristic.
Period :The limit from 10% of base frequency to base frequency is reduced torque characteristic.
The voltage is output in the curve of 1.7 power for frequency.
Period :The voltage is constant from the base frequency to the maximum frequency.
Chapter4 Explanation of function
A044/A244:1
st
/2
nd
control system
b100/b102/b104/b106/b108/b110/b112
: Free setting V/f frequency 1/2/3/4/5/6/7
b101/b103/b105/b107/b109/b111/b113
: Free setting V/f voltage 1/2/3/4/5/6/7
Relation code
Output frequency (Hz)
Output
Voltage (100%)
Base
frequency
Maximum
frequency
0
Base
frequency
Output voltage
(100%)
Output frequency
Maximum
frequency
0
10% of
Basic frequency
VP
（
f
1.7
）
VC
a
b
c
a
c
b
