Cisco Router XR 12416 Installation Manual page 39

Chapter 1 Product Overview
You should inspect and clean the air filter one time per month (more often in dusty
Caution
environments). Do not operate the router without an air filter installed.
The blower module controller card monitors and controls operation of three
variable-speed fans in the blower modules. The variable-speed feature allows
quieter operation by running the fans at below maximum speed, while still
providing adequate cooling to maintain an acceptable operating temperature
inside the card cages.
Two temperature sensors on each line card monitor the internal air temperature in
the card cages:
•
•
•
•
For additional troubleshooting information, see the
section on page
OL-17440-01
When the ambient air temperature is within the normal operating range, the
fans operate at their lowest speed, which is 55 percent of the maximum speed.
If the air temperature rises inside the card cages the fan speed increases to
provide additional cool air to the cards.
If the air temperature continues to rise beyond the specified threshold, the
system environmental monitor shuts down all internal power to prevent
equipment damage due to excessive heat.
If the system detects that one of the three fans within a blower module has
failed, it displays a warning message on the console window. In addition, the
two remaining fans go to full speed to compensate for the loss of the one fan.
If another fan fails, the system shuts down to prevent equipment damage.
4-36.
Cisco XR 12416 and Cisco XR 12816 Router Chassis Installation Guide
Blower Module
"Blower Module Operation"
1-39