Siemens S5-135U/155U - Manual (Page 319)

8-7
System Manual
C79000-G8576-C199-06
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
F+
L+
I/O Modules
230V AC
CC/EU
–951
a)
c)
b)
Battery
L+
Power Supply
Load Power Supply 24V
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
mF 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
mF/40 V
capacitor in parallel.
10000
µ
F/
40V
CC/EU
F+
L+
230V AC
I/O Modules
Load Power Supply 24V
Power Supply
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
Digital Input/Output Modules