Siemens S5-135U/155U - Manual (Page 116)

4-50
System Manual
C79000-G8576-C199-06
If a fan fails (its speed decreases) a fault is indicated, i.e. the red LED
assigned to the fan lights up:
“Fan 1” LED = left fan failed
“Fan 2” LED = middle fan failed
“Fan 3” LED = right fan failed
If a fan fails, the following takes place:
Stage Description
1 A fan fails.
Result:
– The red LED assigned to the fan lights up.
2 Contacts 9 and 10 in the “Warning” relay are closed.
3 The faulty fan is switched off.
4 The other two fans operate at increased voltage and an audibly higher
speed.
If another fan fails, the following takes place:
Stage Description
5 Another fan fails.
Result:
– The red LED assigned to the fan lights up.
6 Contacts 12 and 13 in the “Alarm” relay are closed.
Result:
– “Alarm” LED lights up.
– Two “Fan”-red LEDs light up.
7 A data save routine is started and, with the appropriate jumper setting, an
output inhibit is issued.
8 The power supply switches off, with the appropriate jumper setting.
When the fault has been cleared (faulty fan replaced, filter mat replaced),
you can reset the fault messages by pressing the Reset button.
!
Caution
You can suppress the shutdown of the power supply by opening jumper F-R.
In this case, you must ensure that the power supply is switched off after 60
secs at the latest. This can be achieved with a time relay, for example. This
prevents modules from overheating and being damaged.
Behavior Upon
Failure of Fans
Failure Indication
If a Fan Fails
If Another Fan
Fails
Resetting the Fault
Message
Central Controllers and Expansion Units Power Supply Units