Hitachi SJ Series User Manual page 328

Chapter 12
12.14 Changing the Start Mode
12.14.1 Starting with increasing voltage
gradually
Q
• How to minimize overcurrent at starting when the
minimum frequency has been set high to obtain a
higher torque.
A
• This function allows you to make the inverter
increase the voltage gradually when starting the
motor while outputting the minimum frequency.
• The time to reach the output voltage for the
reduced voltage start can be set with [Hb131].
Item
Minimum frequency
Reduced voltage start
time
FW
Minimum
frequency
[Hb130]
Output
Output voltage
Reduced voltage start time
[b131]
Parameter
[Hb130]
[Hb131]
0ms 10ms 60ms
!
• Set a small value for the reduced voltage start
selection [Hb131] if you intend to increase the start
torque. On the other hand, setting a small value will
cause the inverter to perform full-voltage starting
and to easily trip because of overcurrent.
• This function is effective only when V/f control
(constant torque characteristics, reduced torque
characteristics, or free V/f control) is selected for
the control method [AA121].
Data
0.00~10.00(Hz)
0~2000(ms)
12-14-1
Inverter Function
Description
This is the start frequency.
Increases the output voltage over
the set time, from the operation start
to the voltage command equivalent
to the minimum frequency.