• Supported Platforms
• T640 Routers

• Related Topics
• T640 Cooling System Description
• Troubleshooting the T640 Cooling System
• Replacing a T640 Fan Tray

Maintaining the T640 Fan Trays

Purpose

For optimum cooling, verify the condition of the fans.

Action

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 show chassis environment command. The output is similar to the following:
  
  

  user@host> show chassis environment

  Fans  Top Left Front fan             OK         Spinning at normal speed 
        Top Left Middle fan            OK         Spinning at normal speed 
        Top Left Rear fan              OK         Spinning at normal speed 
        Top Right Front fan            OK         Spinning at normal speed 
        Top Right Middle fan           OK         Spinning at normal speed 
        Top Right Rear fan             OK         Spinning at normal speed 
        Bottom Left Front fan          OK         Spinning at normal speed 
        Bottom Left Middle fan         OK         Spinning at normal speed 
        Bottom Left Rear fan           OK         Spinning at normal speed 
        Bottom Right Front fan         OK         Spinning at normal speed 
        Bottom Right Middle fan        OK         Spinning at normal speed 
        Bottom Right Rear fan          OK         Spinning at normal speed 
        Rear Tray Top fan              OK         Spinning at normal speed 
        Rear Tray Second fan           OK         Spinning at normal speed 
        Rear Tray Third fan            OK         Spinning at normal speed 
        Rear Tray Fourth fan           OK         Spinning at normal speed 
        Rear Tray Fifth fan            OK         Spinning at normal speed 
        Rear Tray Sixth fan            OK         Spinning at normal speed 
        Rear Tray Seventh fan          OK         Spinning at normal speed 
        Rear Tray Bottom fan           OK         Spinning at normal speed 
  

  Top Left and Top Right refer to fans in the upper front fan tray. Bottom Left and Bottom Right refer to fans in the lower front fan tray. Blower or Rear refers to the fans in the rear fan tray.