Siemens S5-135U/155U appendix Behavior Upon Failure of Fans, If a Fan Fails, If Another Fan

Central Controllers and Expansion Units Power Supply Units

Behavior Upon

Failure of Fans

Failure Indication If a fan fails (its speed decreases) a fault is indicated, i.e. the red LED assigned to the fan lights up:

ªFan 1º LED = left fan failed ªFan 2º LED = middle fan failed ªFan 3º LED = right fan failed

If a Fan Fails If a fan fails, the following takes place:

Stage

1

2

3

4

	Description
A fan fails.
Result:	± The red LED assigned to the fan lights up.

Contacts 9 and 10 in the ªWarningº relay are closed.

The faulty fan is switched off.

The other two fans operate at increased voltage and an audibly higher speed.

If Another Fan	If another fan fails, the following takes place:
Fails

Stage

Description

5

6

7

Another fan fails.
Result:	± The red LED assigned to the fan lights up.

Contacts 12 and 13 in the ªAlarmº relay are closed.

Result:± ªAlarmº LED lights up.

± Two ªFanº-red LEDs light up.

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.

Resetting the Fault Message

!

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.

4-50	System Manual
	C79000-G8576-C199-06