NOTE: If the AC LED and the DC LED are unlit, either the AC power cord is not
installed properly or the power supply fuse has failed.
If the AC LED is lit and the DC LED is unlit, the AC power supply is installed
properly, but the power supply has an internal failure.
Related
Documentation
AC Power Supply in EX4550 Switches on page 41•
• AC Power Supply Specifications for EX4550 Switches on page 85
• Connecting AC Power to an EX4550 Switch on page 163
DC Power Supply in EX4550 Switches
The DC power supply in EX4550 switches is a hot-insertable and hot-removable
field-replaceable unit (FRU): You can install it without powering off the switch or
disrupting the switching function.
All the EX4550 switches that are powered by DC power supplies, except the
EX4550-32F-S switches are shipped with one DC power supply pre-installed in the rear
panel of the switches. EX4550-32F-S switches are not shipped with pre-installed power
supplies; you must order them separately.
This topic describes the DC power supplies used in EX4550 switches.
The DC power supply gives an output power of 650 W. Figure 27 on page 45 shows a DC
power supply for an EX4550 switch.
NOTE: The V+ terminals are shunted internally together, as are the V-
terminals. The same polarity terminal can be wired together from the same
source to provide an additional current path in a higher power chassis. Each
power supply must be connected to a single source only.
Copyright © 2015, Juniper Networks, Inc.44
EX4550 Switch Hardware Guide