Siemens S5-135U/155U - Manual (Page 127)

4-61
System Manual
C79000-G8576-C199-06
You can set jumper F-R on the power supply units to choose whether or not
the air flow monitor should switch off the internal supply voltage V
o/p
(5 V)
when a fan fails.
S
Jumper F-R closed: V
o/p
shutdown (signaled by contact)
S
Jumper F-R open: no V
o/p
shutdown (signaled by contact)
If one or both fans are at standstill, the signaling relay drops out (monitor
output). The “Fan Fault” LED lights up simultaneously.
S
Relay contacts 2-1 closed: fan running
S
Relay contacts 2-3 closed: fan failure
Relay contacts 2-3 closed; this is also the normally closed contact during
power OFF (failsafe).
!
Caution
If an immediate shutdown is not possible, jumper F-R must be opened. In
this case you must ensure that the power supply is switched off after 60 s at
the latest. This can be achieved with a time relay, for example. It avoids
overheating and destruction of modules.
Setting the Fan
Monitor
Central Controllers and Expansion Units Power Supply Units