Siemens S5-155U System Manual page 307

Separate or common
shutdown of the CC/EU and
load power supply
Common shutdown of the
CC/EU and load power supply
with a 230 V AC supply
System Manual
C79000-B8576-C199-03
When there is a need to switch off the load power supply separately
without affecting the enabling of modules, there are the following
possibilities for producing the enable voltage. These exist even when
the power supply is used without an additional capacitor and common
shutdown.
230 V AC supply for CC/EU and load power supply
a)
-951
230 V AC
Load Power Supply 24 V
Enable supply from:
a) 6ES5 951-4LB11 load power supply
b) Battery
c) Terminals for 24 V on the front plate of the power supply
Proper functioning is ensured if the 24 V load power supply has an
output capacitance of at least 4700 µF per 10 A of load current.
Other units (load power supply for 20 or 40 A) which do not meet this
condition can be adapted to this requirement by connecting a
10000 µF/40 V capacitor in parallel.
230 V AC
Load Power Supply 24 V
Technical Description
b)
I/O Modules
F +
CC/EU
L +
Power Supply
L +
I/O Modules
F +
CC/EU
L+
Power Supply
Battery
c)
8
µ
10000 F/
40 V
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