Juniper EX4400 - Page 211

8. Place the power supply in the anstac bag or on the anstac mat placed on a at, stable surface.
9. Install the replacement power supply.
NOTE: You must install both the power supplies and they must be operaonal for opmal
funconing of the switch.
Install a Power Supply in an EX4400 Switch
Before you install a power supply:
• Ensure that you understand how to prevent electrostac discharge (ESD) damage (see Prevenon of
Electrostac Discharge Damage ).
• Ensure that you have the correct power supply. If the label on the installed fan module is AIR IN, you
must install a power supply with the label AIR IN. If the label on the installed fan module is AIR OUT,
you must install a power supply with the label AIR OUT.
• Ensure that you have the following parts and tools available:
• Number 2 Phillips (+) screwdriver—not provided
• An ESD grounding strap—not provided
We ship EX4400 switches with one AC or DC power supply preinstalled in the rear panel. Each power
supply is a hot-removable and hot-insertable eld-replaceable unit (FRU) when the second power supply
is installed and running. You can remove and replace either one of them without powering o the switch
or disrupng switch funcons.
CAUTION: Do not mix:
• AC and DC power supplies in the same chassis.
• Dierent models of power supplies (such as 550-W, 1050-W, and 1600-W models)
in the same chassis.
• Power supplies with dierent airow direcons in the same chassis.
• Power supplies and fan modules with dierent airow direcons in the same chassis.
To install a power supply:
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