Table 32: N+N Ac Power Calculations For 24-Port Ex4300 Switches - Juniper EX4300 Hardware Manual

EX4300 Switch Hardware Guide

Table 32: N+N AC Power Calculations for 24-Port EX4300 Switches

Power Supply Rating
PSU PSU
0 1
350 W AC –
350 W AC 350 W AC
350 W AC 715 W AC
54
You can configure the power management software to manage switch power for N+N
redundancy. When you configure power management for N+N redundancy, half of the
total power available (N) is held as reserve power while the other half (N) is available
for immediate consumption. If the switch configuration changes and requires additional
power, then additional power is drawn from the reserve power, and the switch no longer
has N+N power supply redundancy. This condition raises a minor alarm. If the condition
is not corrected within 5 minutes, then a major alarm is issued.
For more information about how power management allocates power to chassis
components when power is insufficient, see Understanding Power Management on EX
Series Switches.
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))
Backup power available = 0 W
A minor alarm is raised as the switch has no N+N power supply redundancy.
If two power supplies are installed in the switch:
System power budget = (Output wattage of the power supply that has the lower
output wattage) – (5% of the output wattage of the power supply that has the lower
output wattage)
System power budget = MIN(PSU
PSU (W))
1
Backup power available = (Output wattage of the power supply that has the lower
output wattage) – (5% of the output wattage of the power supply that has the lower
output wattage)
Backup power available = MIN(PSU
PSU (W))
1
Table 32 on page 54 lists the N+N power calculation for 24-port EX4300 switches that
use 350 W, 715 W AC, and 1100 W AC power supplies.
System
Total Power
Power (in Budget (in
watts) watts)
350 350
700 350
1065 350
(W), PSU (W)) – (0.05 x MIN (PSU
0 1
(W), PSU (W)) – (0.05 x MIN (PSU
0 1
Backup Base
Power (in Power (in
watts) watts)
0 150
332.5 150
332.5 150
Copyright © 2017, Juniper Networks, Inc.
(W),
0
(W),
0
Ports
Available enabled
PoE Power for
(in watts) PoE+
200 6
200 6
200 6