Juniper Core Router T Series Hardware Manual page 313

Copyright © 2018, Juniper Networks, Inc.
NOTE: The current sharing between PEMs relies on equal voltages at the
input terminals of the PEMs. The T320 Internet Router system power is
divided into two load zones. (
of
INPUT 0 PEM1
Therefore, those two PEMs voltages should be equal for current sharing.
However, if the voltages do not match, the router operates normally as
long as the DC input voltages are within the operating range provided in
"T320 Power System Electrical Specifications" on page
on page 98 for a typical DC source cabling arrangement.
Make sure that the power and grounding cables are arranged so that they do not
obstruct access to other router components.
Routinely check the LEDs on the power supply faceplates. If the
the power supplies are functioning normally. For more information about the power
supply LEDs, see "T320 Power System Description" on page
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
The power supplies require an unobstructed airflow at both the front and rear of the
chassis. 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.
Periodically inspect the site to ensure that the grounding and power cables connected
to the router are securely in place and that there is no moisture accumulating near the
router. To review grounding and site wiring requirements for the router, see
Chassis Grounding Cable and Lug Specifications" on page 93
Guidelines for Juniper Networks Devices" on page
Regularly inspect the air filter on each power supply for dust and debris, and replace
the filter element every 6 months. To replace a power supply filter element:
Grasp the filter cover on the power supply faceplate and pull it straight off the power
1.
supply.
Remove the filter element.
2.
Install a new filter element.
3.
Press the filter cover straight onto the power supply faceplate until all four sides
4.
click into place.
of
INPUT 0 PEM0
; of should be matched with
INPUT 1 PEM0
361.
Chapter 31: Maintaining Components
should be matched with
of
INPUT 1 PEM1
96. See Figure 35
LEDs are lit,
CB ON
83.
"T320
and "Site Electrical Wiring
)
285