Siemens Simatic CFU Commissioning Manual page 39

Connecting power supply (X80 and X81)
Plug with screw-
type terminals
1L+
1M
2L+
2M
x
Figure 7-1
NOTICE
Potentials
The freely configurable channels of the CFU are connected to the potentials of the power
supplies (not isolated).
In case of polarity reversal of the power supply, a short circuit is possible via the ground
connections.
Read section "Use in hazardous areas (Page 24)" if needed.
The M and L+ wires of a power supply must be connected to the plug (X8<n>).
● The power supply is connected using two 2-pin plugs (plug-in terminal blocks).
● A redundant power supply can be connected (plug connectors X80 and X81).
– Both inputs are decoupled.
– The ground connections of the plugs (1M and 2M) are connected to each other in the
– There is no load distribution.
– With redundant infeed, the power supply unit with the higher output voltage supplies the
● 2 contacts each are located over each other for each potential (L+ and M). This ensures
that the power supply can be looped through (current: maximum 10 A).
● The power supply has a high-impedance connection with the enclosure to enable an
ungrounded installation.
● Observe the wiring rules.
● The maximum cross-section of the connection is 2.5 mm
SIMATIC CFU
Commissioning Manual, 07/2018, A5E39252870-AC
Connection scheme
Supply voltage: 24 VDC
Supply voltage: Ground
Supply voltage: 24 VDC
Supply voltage: Ground
Spring opener
Connection supply voltage (plug with screw-type terminals / connection scheme / plug with
push-in terminals)
CFU.
device exclusively.
7.3 Connecting the power supply to the CFU
Plug with push-in terminals
. A strain relief is not present.
2
Connecting
39