Maintaining the Power Supplies

To verify that the power supplies are functioning normally, perform the following procedures on a regular basis:

• Check the LEDs on the faceplate of both power supplies. The green OK LED indicates that the power supply is functioning normally; the amber FAULT LED indicates a power supply fault. For more information, see Power Supply LEDs.
• Issue the following CLI command to check the status of the power supplies. As shown in the sample output, the value OK in the Status column indicates that the power supply is operating normally:
  user@host> show chassis environment

  Class Item                   Status     Measurement Power Power Supply A         OK                    Power Supply B         OK ... 
  

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

• Check the red and yellow alarm LEDs on the craft interface. Power supply failure or removal triggers an alarm that causes one or both of the LEDs to light. You can display the associated error messages by issuing the following CLI command:
  user@host> show chassis alarms

  For a list of possible alarm messages, see Hardware and Interface Alarm Messages.

• Verify that the power source has the proper current rating and that each power supply is connected to a separate power source.
• Verify that the cable or cord connecting the power supply to the external power source is securely in place and that there is no moisture accumulating near the router.
• Verify that the cable or cord from the power source to the router is not damaged. If the insulation is cracked or broken, replace the cable or cord immediately.
• Verify that the power cables or cord do not touch or obstruct access to other router components, and that they do not drape where people could trip on them.
• Verify that the air flow in and out of cooling system components is not obstructed.