Maintaining The Mx2020 Fan Trays - Juniper MX2020 Hardware Manual

Maintaining the MX2020 Fan Trays

Purpose
For optimum cooling, verify the condition of the fans.
Action
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. During normal operation, the fans in each fan tray function at normal speed.
To display the status of the cooling system, issue the show chassis environment command, show chassis
environment monitored command, show chassis temperature-thresholds command, or show chassis
fan command.
For the fan trays, the output for the show chassis environment command is similar to the following:
user@host> show chassis environment
Class Item
Temp PSM 0
PSM 1
PSM 2
PSM 3
PSM 4
PSM 5
PSM 6
PSM 7
PSM 8
PSM 9
PSM 10
PSM 11
PSM 12
PSM 13
PSM 14
PSM 15
PSM 16
PSM 17
PDM 0
PDM 1
PDM 2
PDM 3
CB 0 IntakeA-Zone0
CB 0 IntakeB-Zone1
Status Measurement
Absent
Absent
Absent
Absent
OK 34 degrees C / 93 degrees F
OK 31 degrees C / 87 degrees F
OK 30 degrees C / 86 degrees F
OK 30 degrees C / 86 degrees F
OK 31 degrees C / 87 degrees F
Absent
Absent
Absent
Absent
OK 32 degrees C / 89 degrees F
OK 31 degrees C / 87 degrees F
OK 30 degrees C / 86 degrees F
OK 30 degrees C / 86 degrees F
OK 30 degrees C / 86 degrees F
OK
OK
OK
OK
OK 25 degrees C / 77 degrees F
OK 29 degrees C / 84 degrees F
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