Juniper T640 Hardware Manual page 491

Copyright © 2017, Juniper Networks, Inc.
Front Air Filter Element on a T640 AC or DC Power Supply" on page
side air filter, see "Replacing a Side Air Filter on a T640 AC Power Supply" on page
Routinely check the LEDs on the DC power supply faceplates.
For a two-input 160-A DC power supply:
The blue DC OK LEDs light to indicate that the power supplies are functioning
normally.
The LED is lit, indicating that the circuit breaker is on.
CB ON
For a three-input 240-A DC power supply or four-input 240-A DC power supply:
The blue LED is on, the power source is good and the power supplies are
DC OK
functional.
Each INPUT PRESENT
power.
The LED is lit, indicating that the circuit breaker is on.
CB ON
For a six-input DC power supply:
The blue DC OK LED is on, the power source is good and the power supplies are
functional.
Each
INPUT PRESENT
power.
Routinely check the LEDs on the AC power supply faceplates. For a three-phase delta
or wye AC power supply:
The green AC OK LED lights to indicate that the power supply is receiving source AC
power.
The blue LED lights to indicate that the power supply is functioning normally.
DC OK
Check the red and yellow alarm LEDs and the LCD 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 LCD. You can display the associated error messages
by issuing the CLI command:
user@host> show chassis alarms
For a list of possible alarm messages, see
on page 476.
Issue the show chassis environment pem
supplies.
For further description of the output from the commands, see show chassis environment
pem.
user@host> show chassis environment pem
LED is lit, indicating that the input is receiving source DC
LED is lit, indicating that the input is receiving source DC
"Troubleshooting the T640 Power System"
command to check the status of the power
Chapter 32: Maintaining Components
391. To replace a
393.
457