Maintaining the Power Supplies

Purpose

For optimum router performance, verify the condition of the power supplies.

Action

• Periodically check the site to ensure that both the air intake at the bottom front of the chassis and the exhaust from the power supply faceplates are unobstructed. The power supplies require an unobstructed airflow at both the front and rear of the chassis.
• Periodically inspect the site to ensure that the grounding and power cables connected to the TX Matrix router are securely in place and that there is no moisture accumulating near the TX Matrix router. To review grounding and site wiring requirements for the TX Matrix router, see TX Matrix Chassis Grounding Specifications and Site Electrical Wiring Guidelines for M Series, MX Series, and T Series Routers.
• Regularly inspect the air filter on each power supply for dust and debris. Replace the filter element every 6 months. To replace a power supply filter element, see .
• Routinely check the LEDs on the power supply faceplates. If the CB ON LEDs are lit, the power supplies are functioning normally. For more information about the power supply LEDs.
• Check the red and yellow alarm LEDs and the LED display on the craft interface. Power supply failure or removal triggers an alarm that causes one or both of the LEDs to light and an error message to appear on the LED display. You can display the associated error messages by issuing the CLI command:
  user@host> show chassis alarms scc

  For a list of possible alarm messages, see TX Matrix Chassis and Interface Alarm Messages Overview.

• Issue the show chassis environment pem command to check the status of the power supplies. The output is similar to the following:
  user@host> show chassis environment pem scc

  user@host> show chassis environment pem scc
  scc-re0:
  --------------------------------------------------------------------------
  PEM 0 status:
  State Online
  Temperature 29 degrees C / 84 degrees F
  DC input: OK
  DC Output: Voltage Current Power Load
  SIB 0 55141 6156 339 45
  SIB 1 55550 6218 345 46
  SIB 2 55491 5981 331 44
  SIB 3 55450 6331 351 46
  SIB 4 55633 6331 352 46
  PEM 1 status:
  State Online
  Temperature 29 degrees C / 84 degrees F
  DC input: OK
  DC Output: Voltage Current Power Load
  SIB 0 55122 6166 340 45
  SIB 1 55254 6228 346 47
  SIB 2 55258 5951 332 48
  SIB 3 55546 6321 352 50
  SIB 4 55971 6341 353 47

  Note: If 0 is displayed for the SCG/CB/SIB in the Current, Power, and Load fields for a PEM, and the voltage field does not match the other PEM, it might indicate a difference between the DC input voltages applied to PEM0 and PEM1. Consider checking your DC power network for unintended voltage drops to the TX Matrix router. The current sharing between PEMs relies on equal voltages at the input terminals of the PEMs. The TX Matrix router system power is divided into two load zones, one load zone consists of INPUT 0 of PEM0 and PEM1, while the other load zone consists of INPUT 1 of PEM0 and PEM1. Load sharing will occur only between the PEMs of each load zone (INPUT 0 or INPUT 1); therefore, those two PEMs voltages are the ones that should be equal for current sharing. However, if the voltages do not match, the TX Matrix router operates normally as long as the DC input voltages are within the operating range.

• Make sure that the power and grounding cables are arranged so that they do not obstruct access to other TX Matrix router components.