Figure 24: Dc Power Supply - Juniper EX4500 Hardware Manual

Copyright © 2017, Juniper Networks, Inc.

Figure 24: DC Power Supply

DC terminal block
Ejector
lever
Power Power
supply supply
LED handle
NOTE: A 1200 W DC power supply requires a dedicated 30 A circuit breaker
for the input DC feed.
Each DC power supply has an ejector lever that holds the power supply in place. The
ejector lever locks into the corresponding hole in the chassis. For instructions for installing
the power supply, see "Installing a DC Power Supply in an EX4500 Switch" on page
Each power supply has its own fan and is cooled by its own internal cooling system. The
airflow for a power supply is from the front of the power supply to the back.
The color of the ejector lever on the power supply indicates the direction of airflow of
the power supply.
Green—Front-to-back airflow
The color of the power supply's ejector lever must match the color of the exhaust label
visible through the vents of the installed fan tray. The color match indicates that the
direction of airflow through the fan tray matches the direction of airflow through the
power supply.
CAUTION: Verify that the direction of airflow through the power supply
matches the direction of airflow through the fan tray to prevent overheating
of the chassis.
Each DC power supply provides power to all components in the switch. Two power
supplies provide full power redundancy to the switch. If one power supply fails or is
removed, the second power supply balances the electrical load without interruption. The
switch reassesses the power required to support the switch configuration and issues
error messages if the available power is insufficient.
The output for the DC power supply is 12 VDC. The output power is 1200 W.
Chapter 4: Power Supplies
187.
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