Table 51: Airflow Direction In Dc Power Supply Models For Ex4300 Switches; Table 52: N+0 Dc Power Calculations For Ex4300 Switch Configurations - Juniper QFabric QFX3000-G Hardware Documentation

Table 51: 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)
N+0 Redundancy Configuration of DC Power Supplies

Table 52: N+0 DC Power Calculations for EX4300 Switch Configurations

Number of
Switch Power
Configuration Supplies
24-port EX4300 1
switch
2
32-port EX4300 1
switch
2
Copyright © 2018, Juniper Networks, Inc.
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.
In an N+0 redundancy configuration, no power is reserved for resiliency regardless of
number of power supplies installed in the switch.
Depending on the power supplies installed in the switch, you can determine the system
power budget.
If one power supply is installed in the switch:
System power budget = Output wattage of the installed power supply (PSU(W))
If two power supplies are installed in the switch:
System power budget = (Sum of the output wattage of the two power supplies) –
(10% of the output wattage of the installed power supply)
System power budget = PSU
Table 52 on page 173 lists the N+0 power calculation for EX4300 switches that use 550 W
DC power supplies.
NOTE: The DC power supply in the switch does not support Power over
Ethernet (PoE); you can use either an external power injector or an AC power
supply to supply power to PoE devices that you connect to the switch. 32-port
EX4300 switches does not support Power over Ethernet (PoE).
Total Power (in
watts)
550
1100
550
1100
(W) + PSU (W) – (0.10 x (PSU(W))
0 1
Usable System Backup Power
Power (in watts) (in watts)
550 0
1045 0
550 0
550 550
Chapter 7: EX4300 Overview
Base Power (in
watts)
150
150
149
160
173