N700 Operating Instructions and Parts Manual
8. Explanation of b-Group
80
8.14
Overload restriction/Overload advance notice (b030~b033)
(1) Overload
restriction
①
The Inverter monitors the motor current at acceleration and constant speed, when the
inverter reaches the overload restriction level, the inverter will reduce the output
frequency automatically to restrict the overload.
②
This function prevents an over-current trip by inertia during acceleration or radical
changes of load at constant speed.
③
The overload restriction level limits the current at which this function operates.
④
The overload restriction constant is the time to decelerate from max frequency to 0Hz.
⑤
In order to make this function work properly, the acceleration time should be longer than
setting time.
⑥
If the overload restriction constant is set too short, in spite of accelerating, an over-voltage
trip is caused with regenerative energy from the motor at automatic deceleration by this
function.
⑦
When this function operates while accelerating, the frequency will not reach the goal
frequency, the Inverter will adjust in the following way.
Make an acceleration time longer.
Raise a torque boost.
Raise a overload restriction level.
Code
Function name
Initial
value
Unit
Setting
range
Contents
0 Invalid
1
Acceleration/valid on constant speed
2
Valid on constant speed
b030
Overload restriction
Selection
1 -
3
Acceleration/valid on constant speed
[speed increasing at regenerating mode ]
b031
Overload
restriction Level.
1.5 times 0.5~2.0
Rated current x 0.5 to Rated current x 2.0
Current value overload restriction operates.
b032
Overload restriction
constant.
3.0 -.
0.1~30.0 Deceleration
time at overload limitation action
0
valid on Constant speed/Acceleration/
Deceleration
b033
Overload advance notice
signal output mode
0 -
1
Only, Valid on constant speed
Table 8- 19 Overload restriction/Overload advance notice (b030~b033)
Fig. 8- 10 The waveform for Overload restriction/Overload advance notice
