Power Module Fans - Cisco ASR 9000 Series Installation Manual

Chapter 4 Troubleshooting the Installation
In the Cisco ASR 9912 Router, the rear-insertion fan trays draw cooling air from the front of the chassis
into the card cage and then up through the chassis to exit out the rear (see
The fan tray contains 12 fans (Cisco ASR 9010 Router, Cisco ASR 9904 Router,
Cisco ASR 9922 Router, and Cisco ASR 9912 Router) or six fans (Cisco ASR 9006 Router), a
controller card, and one front panel status LED indicator:
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•
If the air temperature inside the chassis rises, blower speed increases to provide additional cooling air to
the internal components. If the internal air temperature continues to rise beyond the specified threshold,
the system environmental monitor shuts down all internal power to prevent equipment damage because
of excessive heat.
If the system detects that one or more of the fans in the fan tray has failed, it displays a warning message
on the system console. In addition, the remaining fans go to full speed to compensate for the loss of the
failed fan.
Due to air leakage, the chassis should not be operated with any of the fan trays completely missing.
Note
Replace any missing fan tray within five minutes. Any fan tray replacement should be performed when
the chassis is back to room temperature.

Power Module Fans

Each AC or DC power module is equipped with two fans that draw cooling air in through the front of the
power module and force warm air out the back of the power tray:
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For additional power supply troubleshooting information, see the
Subsystem" section on page
For the RSP/RP to communicate properly to a power module in a power tray, input power to at least one
Note
of the three power modules in the power tray should be present.
Green—Fan tray is functioning properly.
Red—There is a fault detected in the fan tray.
If the power source is within the required range, the power supply fan remains on.
If a fan fails:
Power module detects an internal overtemperature condition.
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Fault and Temp indicators light.
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Power module sends an overtemperature warning to the system and then shuts down the system.
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4-7.
Cisco ASR 9000 Series Aggregation Services Router Hardware Installation Guide
Troubleshooting the Cooling Subsystem
Figure 1-16).
"Troubleshooting the Power
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