“B” Group: Fine-Tuning Functions
Configur
ing Dr
iv
e
P
a
ra
meters
3–36
Overload
Restriction
If the inverter’s output current exceeds a
preset current level you specify during
acceleration or constant speed, the
overload restriction feature automati-
cally reduces the output frequency to
restrict the overload. This feature does
not generate an alarm or trip event. You
can instruct the inverter to apply
overload restriction only during
constant speed, thus allowing higher
currents for acceleration. Or, you may
use the same threshold for both acceler-
ation and constant speed. In the case of
controlled deceleration, the inverter monitors both output current and DC bus voltage. The
inverter will increase output frequency to try to avoid a trip due to over-current or over-voltage
(due to regeneration).
When the inverter detects an overload, it must decelerate the motor to reduce the current until it
is less than the threshold. You can choose the rate of deceleration that the inverter uses to lower
the output current.
Motor
Current
Output
Frequency
B023
B022
t
restriction area
0
t
Func.
Code
Name/
Description
Keypad
Range and Settings
Defaults
Run
Mode
Edit
Lo Hi
SRW
OPE
FEF2
FE2
(EU)
FUF2
FU2
(USA)
FF2
F2
(Jpn)
B021
Overload restriction
operation mode
OFF
00
Disable
01
01
01
✘ ✔
Select the operating
mode during overload
conditions
ON
0 1
Enable for acceleration and constant speed
CRT
02
Enable for constant speed only
N-R
03
Enable for accel, decel, and constant speed
B022
Overload restriction setting
(0.20 x rated current) to (1.80 x rated
current) (A)
rated current times 1.50
✘ ✔
B023
Deceleration rate at overload restriction
0.10 to 30.00 (seconds)
1.00
1.00
1.00
✘ ✔
B024
Overload restriction
operation mode (2)
OFF
00
Disable
01
01
01
✘ ✔
Select the operating
mode during overload
conditions
ON
0 1
Enable for acceleration and constant speed
CRT
02
Enable for constant speed only
N-R
03
Enable for accel, decel, and constant speed
B025
Overload restriction setting (2)
Models -004xxx to -550xxx: (0.20 x rated
current) to (2.0 x rated current) (A);
Models -750xxx to -4000xxx: (0.20 x rated
current) to (1.80 x rated current) (A)
rated current times 1.50
✘ ✔
B026
Deceleration rate at overload restriction (2)
0.10 to 30.00 (seconds)
1.00
1.00
1.00
✘ ✔
B027
Overcurrent suppres-
sion enable
OFF
00
Disable
01
01
01
✘ ✔
ON
0 1
Enable
B028
Current limit for active frequency-matching
restart
Models -004xxx to -550xxx: (0.20 x rated
current) to (2.0 x rated current) (A);
Models -750xxx to -4000xxx: (0.20 x rated
current) to (1.80 x rated current) (A)
rated current times 1.0
✘ ✔
B029
Scan time constant for active freq. matching
0.10 to 30.00 (seconds)
0.50
0.50
0.50
✘ ✔