ABB ACS880 - Page 538

Def / Type
FbEq 16b / 32b
DescriptionName / Range /
Selection
No.
Fixed limit / unit32Selects 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.
Underload limit type79.11
1Fixed limit is a constant value for all the speeds.Fixed limit
2Underload limit is calculating by formula.
I
lim
= I
set
* (F
act
/ F
max
)
Where,
I
lim
= 79.80 Underload actual limit
I
set
= 79.13 Underload limit
F
max
= 79.09 Load limit speed scale
F
act
= Actual speed
Linear
3Underload limit is calculated by using the formula:
I
lim
= I
set
* (F
act
/ F
max
)
2
Where,
I
lim
= 79.80 Underload actual limit
I
set
= 79.13 Underload limit
F
max
= 79.09 Load limit speed scale
F
act
= Actual speed
Quadratic
4Underload limit depends on the user input load curve,
actual speed/frequency and Underload supervision
input.
User curve
Motor current % /
unit32
Defines the source for the supervision signal used in
the underload protection.
Underload
supervision signal
79.12
0ZeroNULL
112.12 AI1 scaled value (page 226).AI1 scaled
212.22 AI2 scaled value (page 228).AI2 scaled
33.5 FB A reference 1 (page 179).FB A ref1
43.6 FB A reference 2 (page 179).FB A ref2
53.9 EFB reference 1 (page 179).EFB ref1
63.10 EFB reference 2 (page 179).EFB ref2
7Parameter 9.13 Motor current estimated.Estimated motor
current
8Estimated motor current in % of nominal motor current.Motor current %
See Terms and abbreviations (page 169).Other [value]
0.00 / real32Defines 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 type.
Underload limit79.13
10 = 1 / 100 = 1Underload fixed limit.0.00 ... 30000.00
Constant / unit32Selects the type of underload delay time setting.
The user has option to choose between fixed and
floating delay calculation methods.
Underload delay
type
79.17
0Fixed constant value of the delay.Constant
538 Parameters