Juniper EX4300 Series User Manual

N+N Redundancy Conguraon of DC Power Supplies
You can congure your switch for N + N redundancy, in which N power supplies can be removed or fail
and the remaining N power supplies connue to supply power for the switch without interrupon.
You can congure the power management soware to manage switch power for N + N redundancy.
When you congure 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 consumpon. If the switch
conguraon changes and requires addional power, then addional power is drawn from the reserve
power, and the switch no longer has N + N power supply redundancy. This condion raises a minor alarm.
If the condion is not corrected within 5 minutes, then a major alarm is issued.
For more informaon about how power management allocates power to chassis components when
power is insucient, 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 waage of the installed power supply (PSU(W))
• Backup power available = 0 W
A minor alarm is raised as switch has no
N + N power supply redundancy.
• If two power supplies are installed in the switch:
• System power budget = (Output waage of one power supply) – (5% of the output waage of
one power supply)
System power budget = PSU(W) – (0.05 x PSU(W))
• Backup power available = (Output waage of one power supply) – (5% of the output waage of
one power supply)
System power budget = PSU(W) – (0.05 x PSU(W))
Table 50 on page 118 lists the N + N power calculaon 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).
117

Juniper EX4300 Series Specifications

General

Product Series	EX4300 Series
Power Consumption	Varies by model and configuration
Virtual Chassis Technology	Up to 10 switches
Software	Junos OS
Ports	24-port and 48-port models
10GBASE SFP+ Ports	Up to 8 ports
40GBASE QSFP+ Ports	2
Uplink Ports	Up to 4 ports
Jumbo Frames	Up to 9216 bytes
Operating Temperature	0°C to 45°C
Relative Humidity	5% to 90% noncondensing
Input Voltage	100 to 240V AC
Power Supply	AC or DC
Power Supply Options	AC or DC
Stacking	Yes
Layer 2 Features	Includes VLAN, STP, RSTP, MSTP, LACP
Layer 3 Features	OSPF, BGP
Management	CLI, Web GUI, SNMP
Security Features	DHCP snooping
QoS	8 queues per port, DSCP
Storage Temperature	-40°C to 70°C