Fan Tray Operation
The fan tray maintains acceptable operating temperatures for the internal components by drawing cooling air
into the system chassis. The fan tray receives power from the chassis backplane.
The fan tray contains 14 fans, a controller card, and one front panel STATUS LED indicator:
•
Green
—
Fan tray is functioning properly.
•
Red
—
There is a fault detected in the fan tray.
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.
Power Module Fans
Each AC or DC power module is equipped with one fan that draws cooling air in through the front of the
power module and force warm air out through the air exhaust of the chassis:
•
If the power source is within the required voltage range, the power supply fan remains on.
•
If a fan fails:
◦
Power module detects an internal over-temperature condition.
◦
Fault and Temp indicators light.
◦
Power module sends an over-temperature warning to the system and then power supply switchover
to the redundant power module.
For additional power supply troubleshooting information, see
Troubleshooting the Power Subsystem, on
page 87
.
For the RSP to communicate properly to a power module, input power to at least one of the two power
modules should be present.
Note
Over-temperature Conditions
This console error message indicates that the system has detected an over-temperature condition or
out-of-tolerance power value inside the system:
Queued messages:
%ENVM-1-SHUTDOWN: Environmental Monitor initiated shutdown
Cisco ASR 9001 and Cisco ASR 9001-S Routers Hardware Installation Guide
105
Troubleshooting the Installation
Fan Tray Operation