Hitachi SJ Series, User Manual

Page: 222 / 786

12-9-5
Chapter 12 Inverter Function
12.9.4 Run with V/f control (free V/f)
• To change the characteristics of V/f control in
accordance with the voltage characteristics of a
special motor.
• To adjust manually the voltage characteristics to
optimal ones in order to save energy.
V/f control (free V/f)
• In the free V/f set-up, any intended V/f
characteristics can be set by setting the voltage
and the frequency at 7 points.
• When a motor is hunting and vibrating, an
adjustment of the stability constant [HA110] may
improve the state of the motor.
• The frequencies set by free V/f set-up have to
always meet the following requirement: f1 ≤ f2 ≤ f3
≤ f4 ≤ f5 ≤ f6 ≤ f7 ≤ base frequency. The initial value
for each of the frequencies set by the free V/f
set-up is 0 Hz. Set the maximum frequency and the
base frequency first, and then set the frequencies
f7, f6, f5, f4, f3, f2, and f1 in this order by the free
V/f set-up.
• Setting the [AA121] at 02 (free V/f set-up) disables
the manual torque boost operation mode [Hb140].
Ｑ
Ａ
！
Output frequency (Hz)
f1 f2 f3 f4 f5 f6 f7 0
V2,V3
V1
V5
V6
V7
V4
Output voltage (V)
Base
frequency
Maximum
frequency
Rated
voltage