Overload Restriction/Overload Advance Notice - Hitachi L300P-110L Instruction Manual

(3) Thermal warning
A warning signal is outputted before overheat protection by the electronic thermal protection occurs.
Warning level is set with C061.
Assign 13(THM) to an intelligent output terminal (C021, C022) or the alarm relay output (C061).
Function
code
C061

Overload restriction/Overload advance notice

(1) Overload restriction
The Inverter monitors the motor current on acceleration and constant
speed,
When the inverter reaches the overload restriction level, the Inverter
will reduce the output frequency automatically to restrict the overload.
This function prevents an over-current trip by inertia during acceleration
or radical changes in load at constant speed.
Two kinds of overload restriction function are set with b021, b022, b023
and b024, b025, b026.
To change b021, b022, b023 and b024, b025, b026, assign 39(OLR)
to an intelligent input terminal.
The current value this function operates at is set in overload restriction
level.
The overload restriction constant is the time to decelerate to 0Hz from max. frequency.
b021, b022, b023 and b024, b025, b026 is changed with OLR.
As this function operates, the acceleration time is longer than setting time.
If the overload restriction constant is set too short, in spite of accelerating, an over-voltage trip is caused with
regenerative enegy from the motor on automatic deceleration by this function.
When this function operates in the midst of accelerating, the frequency will not reach the goal frequency, the
Inverter will adjust in the following way.
Make acceleration time longer.
Raise torque boost.
Raise overload restriction level.
Set item Function code
Overload
restriction b021/b024
Selection.
Overload
restriction b022/b025
Level.
Overload
restriction b023/b026
Constant.
Data Description
0. Thermal warning is noneffective
1.-100. Units : %
Data
00
01
02
Rated current x 0.5 to
Rated current x 1.5
0.1 to 30.0
Chapter 4 Explanation of function
b021:Overload restriction selection
b022:Overload restriction level
b023:Overload restriction constant
b024:Overload restriction 2 selection
b025:Overload restriction level2
b026:Overload restriction constant2
C001-C005:Intelligent input terminal
C021-C022:Intelligent output terminal
C026:Alarm relay output setting
C040:Overload advance notice signal
C041: Overload notices level
Description
Invalid
Acceleration/valid on constant speed.
Valid on constant speed.
Units :A
Current value overload restriction operates.
Units :second
Deceleration time when overload restriction
Operates.
4-38
Relation code
output mode