Ac Power Supplies - Juniper EX4200 Hardware Manual

The power supply in EX4200 switches is a hot-removable and hot-insertable field-replaceable unit (FRU)
that you can install on the rear panel without powering off the switch or disrupting the switching function.
EX4200 switches have an internal redundant power supply, making the power supply in EX4200 switches
fully redundant.
All the EX4200 switch models, except the EX4200-24F-S and EX4200-48T-S switches are shipped with
one power supply pre-installed in the rear panel of the switches. EX4200-24F-S and EX4200-48T-S
switches are not shipped with pre-installed power supplies; you must order them separately.
NOTE: This topic uses the term PoE to refer to both PoE and PoE+ unless there is a need to
distinguish between the two.
EX4200 switches use power supplies that provides two DC output voltages: 12 V for system and logic
power and 48–51 V (or higher, to compensate for voltage drops along the path from the power supplies
to the RJ-45 connector) for PoE ports.
NOTE: After powering on the switch, wait for at least 60 seconds before powering it off. After
powering off the switch, wait for at least 60 seconds before powering it back on.
After the switch has been powered on, it can take up to 60 seconds for status indicators—such
as LEDs on the power supply, show chassis command output, and messages on the LCD panel—to
indicate that the power supply is functioning normally. Ignore error indicators that might appear
during the first 60 seconds.
NOTE: EX4200-24PX and EX4200-48PX switches do not support the 930 W (EX-PWR-930-AC)
or the 600 W (EX-PWR-600-AC) AC power supplies that are used in the EX4200-48P and the
EX4200-24P switch models. EX4200-24PX and EX4200-48PX switches work only with the
power supplies labeled EX-PWR2-930-AC or EX-PWR3-930-AC. All EX4200 switches support
EX-PWR2-930-AC and EX-PWR3-930-AC power supplies. You can find the label on the top of
the power supply (see

AC Power Supplies

All the EX4200 switches that are powered by AC power supplies except the EX4200-24F-S and
EX4200-48T-S switches are shipped with one AC power supply pre-installed in the rear panel of the
switches. EX4200-24F-S and EX4200-48T-S switches are not shipped with pre-installed power supplies;
you must order them separately.
"Removing a Power Supply from an EX4200 Switch" on page
48
195).