Maintaining the M40e Fan Tray and Impellers

Purpose

Verify the condition of the fan tray and impellers.

Action

The fan tray is attached to the back of the cable management system and installs into the front of the chassis, as shown in M40e Chassis Description. There are also three separate, non-interchangeable impeller assemblies. The front impeller is located behind the craft interface (shown in M40e Chassis Description) and works together with the fan tray to cool the FPCs and midplane. The upper and lower impellers on the rear of the chassis (shown in M40e Chassis Description) work together to cool the components that install into the rear of the chassis.

To check the status of the impellers and the fans in the fan tray, issue the show chassis environment command. The output includes an entry for each impeller (which it refers to as a Blower) and for each fan in the fan tray:

Class Item                   Status     Measurement 
... 
Fans  Rear Bottom Blower     OK         Spinning at normal speed
      Rear Top Blower        OK         Spinning at normal speed
      Front Top Blower       OK         Spinning at normal speed
      Fan Tray Rear Left     OK         Spinning at normal speed
      Fan Tray Rear Right    OK         Spinning at normal speed
      Fan Tray Front Left    OK         Spinning at normal speed
      Fan Tray Front Right   OK         Spinning at normal speed 
...

For further description of the output from the command, see the Junos OS System Basics and Services Command Reference.