ABB ACS880 Firmware Manual page 538

538 Parameters
No. Name / Range /
Selection
79.11 Underload limit type
Fixed limit
Linear
Quadratic
User curve
79.12 Underload
supervision signal
NULL
AI1 scaled
AI2 scaled
FB A ref1
FB A ref2
EFB ref1
EFB ref2
Estimated motor
current
Motor current %
Other [value]
79.13 Underload limit
0.00 ... 30000.00
79.17 Underload delay
type
Constant
Description
Selects the type of limit used for underload supervision.
The user has option to choose either a fixed limit, a
curve of a predefined shape or plot a custom curve as
a function of motor speed.
Fixed limit is a constant value for all the speeds.
Underload limit is calculating by formula.
I = I * (F / F )
lim set act max
Where,
I = 79.80 Underload actual limit
lim
I = 79.13 Underload limit
set
F = 79.09 Load limit speed scale
max
= Actual speed
F
act
Underload limit is calculated by using the formula:
2
I = I * (F / F )
lim set act max
Where,
I = 79.80 Underload actual limit
lim
I = 79.13 Underload limit
set
F = 79.09 Load limit speed scale
max
F = Actual speed
act
Underload limit depends on the user input load curve,
actual speed/frequency and Underload supervision
input.
Defines the source for the supervision signal used in
the underload protection.
Zero
12.12 AI1 scaled value (page
12.22 AI2 scaled value (page
3.5 FB A reference 1 (page
3.6 FB A reference 2 (page
3.9 EFB reference 1 (page
3.10 EFB reference 2 (page
Parameter 9.13 Motor current
Estimated motor current in % of nominal motor current.
See Terms and abbreviations (page
Defines underload limit value.
Note: This parameter is not applicable in case User
curve is selected for the underload curve shape in
parameter 79.11 Underload limit
Underload fixed limit.
Selects the type of underload delay time setting.
The user has option to choose between fixed and
floating delay calculation methods.
Fixed constant value of the delay.
226).
228).
179).
179).
179).
179).
estimated.
169).
type.
Def / Type
FbEq 16b / 32b
Fixed limit / unit32
1
2
3
4
Motor current % /
unit32
0
1
2
3
4
5
6
7
8
0.00 / real32
10 = 1 / 100 = 1
Constant / unit32
0