Because of the high total current consumption of the digital I/O modules (from
UP = 24 V DC), the supply is divided up into several electric circuits fused
separately.
The maximum permitted total current over the supply terminals of the I/O ter-
minal units is 8 A.
The total current can be calculated as follows:
I
Total
= I
LOGIC
+ I
UP
with the assumptions
I
LOGIC
= I
CPU
+ I
I/O bus
+ I
C1
+ I
C2
+ I
C3
+ I
C4
(CPU + communication m I/O bus)
I
I/O bus
= Number of expansion modules × Current consumption through the I/O bus per module
and
I
UP
= I
UP1
+ I
LOAD1
+ I
UP2
+ I
LOAD2
+ I
UP3
+ I
LOAD3
+ I
UP4
+ I
LOAD4
+ I
UP5
+ I
LOAD5
+ I
UP6
+ I
LOAD6
+ I
UP7
+ I
LOAD7
If one assumes that all outputs are switched on and are operated with their maximum permitted
load currents (under compliance with the maximum permitted currents at the supply terminals),
then the following values are the result for an example shown above:
I
CPU
*)
I
Cx
*)
I
I/O bus
*)
I
UPx
*)
I
LOADx
*)
CPU / communication module part
CPU
0.110 A
-
-
-
-
C1
-
0.050 A
-
-
-
C2
-
0.085 A
-
-
-
C3
-
0.050 A
-
-
-
C4
-
0.050 A
-
-
-
I/O module part
Analog1
-
-
0.002 A
0.150 A
-
Analog2
-
-
0.002 A
0.150 A
0.160 A
Analog3
-
-
0.002 A
0.100 A
0.080 A
Analog4
-
-
0.002 A
0.100 A
0.080 A
Digital1
-
-
0.002 A
0.050 A
8.000 A
Digital2
-
-
0.002 A
0.050 A
8.000 A
Digital3
-
-
0.002 A
0.050 A
8.000 A
S
columns
0.110 A
0.235 A
0.014 A
0.650 A
24.320 A
S
I
LOGIC
≈
0.4 A
S
I
UP
≈
25 A
I
Total
≈
25.4 A
*) All values in this column are exemplary values
2.4.5.2
Dimensioning of the fuses
To be able to select the fuses for the station correctly, both the current consumption and the
inrush currents (melting integral for the series-connected fuse) must be taken into consideration.
System assembly, construction and connection
Overall information (valid for complete AC500 product family) > Power consumption of an entire station
2022/01/31
3ADR010278, 3, en_US
923
