7 Guidelines for station planning
7.3 Power supply
XI/ON: XNE-GWBR-2ETH-IP
09/2011 MN05002007Z-EN
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179
7.3.3
Creating potential groups
Power feeding modules can be used to create potential groups. The potential isolation of
potential groups to the left of the respective power supply modules is provided by the base
modules.
When using I/O modules for 120/230 V AC (XN-2DI-120/230VAC and XN-2DO-120/230VAC-
0.5A), it has to be ensured that a potential group is created in conjunction with the power
feeding module XN-PF-120/230VAC-D.
7.3.4
C-rail (cross connection)
The C-rail runs through all base modules. The C-rail of the base modules for power supply
modules is mechanically separated; thus potentially isolating the adjoining supply groups.
Access to the C-rail is possible with the help of base modules with a C in their designation (for
example, XN-S4T-SBCS). The corresponding connection level is indicated on these modules
by a thick black line. The black line is continuous on all I/O modules. On power supply modules,
the black line is only above the connection 24. This makes clear that the C-rail is separated
from the adjoining potential group to its left.
Note
The system can be supplied with power independent of the potential group forma-
tion.
Attention
It is not permitted to use modules with 24 V DC and 120/230 V AC field supply in a
joint potential group.
Figure 68:
C-rail front view
