Troubleshooting The Cooling Subsystem; Fan Tray Operation - Cisco ASR 9000 Series Installation Manual

Troubleshooting the Cooling Subsystem

The RSP/RP card continuously polls the system for temperature, voltage, current, and fan speed values.
If a threshold value is exceeded, the RSP/RP sets the appropriate alarm severity level on the alarm card,
which lights the corresponding LED, and energizes the appropriate alarm display relays to activate any
external audible or visual alarms wired to the alarm display. The RSP/RP also logs a message about the
threshold violation on the system console.
If one or more of the alarm LEDs is on, check the system console for messages describing the alarm.
Note
Troubleshooting the Cooling Subsystem
You may need to troubleshoot the cooling subsystem if an overtemperature condition occurs. The
cooling subsystem of the router consists of a fan tray in the chassis and a fan in each of the power
supplies. The fan tray and the power supply fans circulate air to maintain acceptable operating
temperatures within the router.
When troubleshooting the fan trays, never unplug all the fan trays at the same time.
Caution
This section contains information to troubleshooting the cooling subsystem and includes:
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Fan Tray Operation

The fan trays maintain acceptable operating temperatures for the internal components by drawing
cooling air through a replaceable air filter into the switch fabric and alarm card cage and then through
the line card and RSP card cage (see
Figure 1-13
Cisco ASR 9904 Router cooling path.
In the Cisco ASR 9922 Router, the fan trays draw cooling air from the front of the chassis into the
middle card cage and then through each of the two line card cages top and bottom (see
fan tray receives power from the chassis backplane through a wiring harness.
Cisco ASR 9000 Series Aggregation Services Router Hardware Installation Guide
4-28
Fan Tray Operation, page 4-28
Power Module Fans, page 4-29
Overtemperature Conditions, page 4-30
Isolating Cooling Subsystem Problems, page 4-30
for the Cisco ASR 9006 Router cooling path, and
Figure 1-12 for the Cisco ASR 9010 Router cooling path,
Figure 1-14
Chapter 4 Troubleshooting the Installation
for the
Figure 1-15). The