Removing A Dc Power Supply In An Ex9253 Switch - Juniper EX9253 Hardware Manual

Failure to do so can result in significant delays if you need replacement parts. This note does not
apply if you replace existing components with the same type of component.
To connect power to an AC power supply, see
Powering on the Switch" on page

Removing a DC Power Supply in an EX9253 Switch

Before you begin to remove a DC power supply:
• Ensure that you understand how to prevent electrostatic discharge (ESD) damage (see
Electrostatic Discharge Damage
Ensure that you have the following parts and tools available:
• An ESD wrist strap
• A socket screwdriver
• A replacement power supply or cover panel for the power supply slot
The DC power supply in an EX9253 switch is a hot-removable and hot-insertable field-replaceable unit
(FRU). You can remove and replace it while the switch is running without turning off power to the switch
or disrupting switching functions. To ensure proper operation of the switch, you must install a
replacement power supply shortly after removing a power supply from the chassis. The power supplies
are installed in the slots labeled PSM0 through PSM5 on the rear of the chassis.
CAUTION: Before you remove a power supply, ensure that you have power supplies
sufficient to power the switch that remains in the chassis (see
on page 27).
CAUTION: Do not leave the power supply slot empty for a long time while the switch is
operational. Either replace the power supply unit promptly or install a cover panel over
the empty slot.
WARNING: Before you perform DC power procedures, ensure there is no power to the
DC circuit. To ensure that all power is off, locate the circuit breaker on the panel board
"Connecting AC Power to an EX9253 Switch and
85.
).
Prevention of
"EX9253 Power System"
127