Overload Restriction - Hitachi SJ300 Series Instruction Manual

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"B" Group: Fine-Tuning Functions
Overload
Restriction
Func.
Name
Code
B021 Overload restriction
operation mode
B022 Overload restriction
setting
B023 Deceleration rate at

overload restriction

B024 Overload restriction
operation mode (2)
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.
"B" Function
Description
Select the operating mode
during overload conditions,
four options, option codes:
00 Disabled
01 Enabled for acceleration
and constant speed
02 Enabled for constant
speed only
03 Enabled for accel, decel,
and constant speed
Sets the level for overload
restriction, between 50%
and 200% of the rated
current of the inverter,
setting resolution is 1% of
rated current
Sets the deceleration rate
when inverter detects
overload, range is 0.1 to
30.0, resolution is 0.1.
Select the operating mode
during motor overload
conditions, four options,
option codes:
00 Disabled
01 Enabled for acceleration
and constant speed
02 Enabled for constant
speed only
03 Enabled for accel, decel,
and constant speed
restriction area
Motor
Current
0
Output
Frequency
B023
Defaults
Run
Mode
Edit
–FE –FU –FR
Lo Hi
(EU) (US) (JP)
✘ ✔
01 01 01
✘ ✔
rated current times
1.50
✘ ✔
1.00 1.00 1.00
✘ ✔
01 01 01
B022
t
t
Units SRW Display
— >b021 OLOAD
1MODE ON
A
>b022 OLOAD
1LEVEL 0024.8A
sec. >b023 OLOAD
1CONST 01.00
— >b024 OLOAD
2MODE ON