User Manual
Section 3
GFK-2958L
May 2021
Configuration
30
Product group
Product
I
SYS
I
IN
I
OUT
I
S
I
L
EP-5422, EP-5442
8 mA
40
mA
EP-5261
8 mA
16 mA
EP-5311
8 mA
25 mA
EP-5324
8 mA
25 mA
x
Power-feed modules
EP-7641
10
mA
EP-7631
10 mA
EP-1901, EP-1902, EP-1922
8 mA
45 mA
x
Potential distribution
modules
EP-751F
-
-
-
-
-
EP-711F
-
-
-
-
-
I
SYS
I
IN
I
OUT
I
S
I
L
x
Current consumption from the system current path
Power consumption from input current path
Power consumption from output current path
Current demand of the connected sensors
Current demand of the connected actuators
Must be included when calculating the power supply
3.6
Example Calculation for the Power Supply
The power supply must be calculated individually for each station installation. Therefore,
the simultaneity factor g and the current demand of each module, as well as the devices to
be connected must be established (refer to the example calculation table).
In the example station, an EPXPNS001 network adapter is configured with four EP-1214
modules and eight EP-2218 modules. The cumulative current demand for each module is
now calculated to determine whether and at which point a EP-7631 power-feed module
must be positioned to refresh the current path. A power-feed module must always be used
where the current demand exceeds 10 A.
Note:
The power refresh must be separately calculated for the input and output current paths. The
system voltage need not be considered during this step.
Use the RSTi-EP Power Supply Configuration Guide to perform this calculation automatically.
Calculation of the Current Demand for the Input Current
The current consumption of the network adapter must be considered for the main power
supply, and the sum of consumption values is multiplied by the simultaneity factor g for
each following module:
I
SYS
network adapter
+ (I
SYS
+ I
IN
) + (I
S
x g) module 1
+ (I
SYS
+ I
IN
) + (I
S
x g) module 2
+
Σ
((I
SYS
+ I
IN
) + (I
S
x g)) modules 3 to 4
= Cumulative current demand
I
SYS
Current consumption from the system
current path
I
IN
Current consumption from the input current
path
I
S
Power supplies for the connected sensors
In the case of an additional power supply (power refresh) with a EP-7631 power-feed
module, only the sensor power supplies and the module current consumption have to be
considered:
