5
-68
N: Special Adjustments
The following settings are made with the special adjustments constants (N constants): Hunting prevention,
speed feedback detection control, high-slip braking, speed estimation, and feed forward control.
Hunting Prevention Function: N1
User constants for hunting prevention are shown in the following table.
* 1. Applicable for G7-
S
eries Inverters with software version PRG: 1033 and later.
* 2. The factory setting depends upon the Inverter capacity. The value for a 200 V Class Inverter of 0.4 kW is given.
Con-
stant
Number
Name
Description
Setting
Range
Factory
Setting
Change
during
Opera-
tion
Control Methods
MEMO
BUS
Regis-
ter
Page
Display
V/f
V/f
with
PG
Open
Loop
Vec-
tor
1
Flux
Vec-
tor
Open
Loop
Vec-
tor
2
N1-01
Hunting-pre-
vention func-
tion selection
0: Hunting-prevention
function disabled
1: Hunting-prevention
function enabled
The hunting-prevention func-
tion suppresses hunting when
the motor is operating with a
light load.
This function is enabled in V/
f control method only.
If high response is to be given
priority over vibration sup-
pression, disable the hunting-
prevention function.
0 or 1
1
No
A
A
No
No
No
580H
6-38
Hunt Prev
Select
N1-02
Hunting-pre-
vention gain
Set the hunting-prevention
gain multiplication factor.
Normally, there is no need to
make this setting.
Make the adjustments as fol-
lows:
• If vibration occurs with
light load, increase the set-
ting.
• If the motor stalls, reduce
the setting.
If the setting is too large, the
voltage will be too suppressed
and the motor may stall.
0.00 to
2.50
1.00
No
A
A
No
No
No
581H
4-17
6-38
Hunt Prev
Gain
N1-03
*1
Hunting-pre-
vention time
constant
Set the hunting-prevention
primary delay time in units of
ms.
0 to
500
10 ms
*2
No
A
A
No
No
No
582H
6-38
Hunt Prev
Time