The load can also be switched via a contact.
Connection of input/output
modules to two power supply
units
Given here are two examples of the feeding of inputs and outputs of
different modules from two power supply units.
With non-floating input/output modules, the negative terminals (L-) of
the power supply units are connected to reference potential (PE)
because the inputs of the 420 module are referred to chassis ground.
Output 1
Output 2
ELR
Phase (L)
Manu-
Load
Neutral (N)
ELR = Electronic Load Relay
ELR
al
Figure 8-11
Parallel Connection of Outputs for AC Voltage Outputs
Reference Potential
+
+
DQ
e.g. 441
0 V
+
+
DQ
e.g. 441
0 V
0 V
e.g. 420
DI
0 V
e.g. 420
DI
2 L +
1 L +
I I
I I
I I I
I I
AC
230 V
DC
24 V
+
_
+
_
AC
230 V
DC
24 V
L
_
Q
L
Q L
Q
Q
Q
Q
L
Q
Q
L
Central Ground Point
or Rack
of the CC/EU
and
Connection
to Protective
Conductor (PE)
Figure 8-12
Feeding of Non-Floating Input/Output Modules from Two Power Supply Units
Installation and Startup
System Manual
8 - 26
C79000-B8576-C199-03
