Maintaining The T640 Fan Trays - Juniper T640 Hardware Manual

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Maintaining the T640 Fan Trays

Purpose
Action
Copyright © 2017, Juniper Networks, Inc.
between 40°F (4° C) to 90°F (32° C). Note that if the material flakes, or becomes brittle
when rubbed or deformed, it is no longer usable.
CAUTION: Always keep both air filters in place while the router is operating.
Because the fans are very powerful, they could pull small bits of wire or other
materials into the router through the unfiltered air intake. This could damage
the router components.
T640 Cooling System Description on page 31
T640 Clearance Requirements for Airflow and Hardware Maintenance on page 122
Replacing a T640 Air Filter on page 281
For optimum cooling, verify the condition of the fans.
On a regular basis:
Monitor the status of the fans. The fan trays each contain multiple fans that work in
unison to cool the router components. If one fan fails, the host subsystem adjusts the
speed of the remaining fans to maintain proper cooling. A red alarm is triggered when
a fan fails, and a yellow alarm is triggered when a fan tray is removed.
To display the status of the fans, issue the
command.
show chassis fan
During normal operation, the fans in each fan tray function at less than full speed.
For the standard front fan trays and standard rear fan tray with eight fans, the output
for the
show chassis environment
user@host> show chassis environment
Class Item
...
Fans Top Left Front fan
Top Left Middle fan
Top Left Rear fan
Top Right Front fan
Top Right Middle fan
Top Right Rear fan
Bottom Left Front fan
Bottom Left Middle fan
Bottom Left Rear fan
Bottom Right Front fan
Bottom Right Middle fan
Bottom Right Rear fan
Rear Tray Top fan
Rear Tray Second fan
Rear Tray Third fan
Chapter 32: Maintaining Components
show chassis environment
command is similar to the following:
Status Measurement
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
command or
445