Dc Power Supply Airflow; Table 37: Airflow Direction In Dc Power Supply Models For Ex4300 Switches - Juniper EX4300 Hardware Manual

Table 36: Details of the DC Power Supplies in EX4300 Switches (continued)
Details
Power supply weight
Minimum installed in chassis
Maximum installed in chassis
Power supply slots
Fans
Airflow
Power supply status LEDs
DC input current rating
Operating range

DC Power Supply Airflow

Table 37: Airflow Direction in DC Power Supply Models for EX4300 Switches

Model Label on Power Supply
JPSU-550-DC-AFO-A AIR OUT (AFO)
JPSU-550-DC-AFI-A
AIR IN (AFI)
Copyright © 2017, Juniper Networks, Inc.
550 W DC Power Supply
2.43 lb (1.1 kg)
1
2
Install in power supply slots labeled
the chassis.
Internal
Front-to-back, indicated by label
Back-to-front, indicated by label
IN OK
4 A
–38 through –60 VDC
NOTE:
–43.5 +/– 0.5 VDC. After the switch is powered on, the operating range is
–38 through –60 VDC.
To prevent electrical injury while installing or removing DC power supplies, carefully follow
instructions in "Installing a DC Power Supply in an EX4300 Switch" on page 236
"Removing a DC Power Supply from an EX4300 Switch" on page
Each power supply has its own fan and is cooled by its own internal cooling system.
Each power supply has a label
power supply that indicates the direction of airflow in the power supply.
Table 37 on page 59 lists the DC power supply models and the direction of airflow in
them.
Direction of Airflow
Front-to-back—that is, air intake to cool the chassis is through the vents
on the front panel of the chassis and hot air exhausts through the vents
on the rear panel of the chassis.
Back-to-front—that is, air intake to cool the chassis is through the vents
on the rear panel of the chassis and hot air exhausts through the vents
on the front panel of the chassis.
and OUT OK
The minimum input power required to power on the switch is
or
AIR OUT (AFO) AIR IN (AFI)
Chapter 4: Power Supplies
and in the rear panel of
PSU 0 PSU 1
AIR OUT (AFO)
AIR IN (AFI)
238.
on the faceplate of the
and
59