Siemens S5-155U System Manual page 99

Establishing the wiring
Establishing the signalling
circuits
Setting up the control input for
the power supply
System Manual
C79000-B8576-C199-03
Wiring of the power supply unit must be planned within the scope of
wiring of the entire control system. The information required for the
purpose and decision-making aids, e.g. for local or central grounding,
can be found in Chapter 3: Installation Guidelines.
Three relay outputs allow you to install additional external signalling
circuits for fault states, e.g. to connect a cabinet lamp or horn.
The following table contains the information required on the relay
states:
Relay
(Normal Operational
State)
Fan Warning All fans are in order.
Fan Alarm Adequate air flow,
at least two fans are
running.
Battery Lithium battery and
Warning rechargeable battery
are in order
(U not
batt ext
connected)
The following applies to the 5 V supply for terminal EN (Enable
Power Supply):
• • Input EN monitors the voltage for < 3.6 V; it enables the output
voltage at 3.6 V.
• • If two or more units are to be controlled jointly, connect input EN
of the PSU in the central controller to the EN inputs of the PSUs in
the expansion unit. Connect the auxiliary voltage U
to these inputs. In the event of failure of the PSU in the central
controller, all units will then be switched off with the appropriate
jumper settings.
Not more than 7 EN inputs may be connected to one U
(front terminal).
Power Supply Units
(Fault State/Idle State)
One or more fans have failed.
Inadequate air flow or at least
two fans have failed.
Lithium battery or
rechargeable battery has failed
(no U )
batt ext
, for example,
H
output
H
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4