Removing An Ac Power Supply From An Ex9253 Switch - Juniper EX9253 Hardware Manual

Removing an AC Power Supply from an EX9253 Switch

Before you begin to remove an AC power supply:
• Ensure 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 replacement power supply or a cover panel for the power supply slot
The AC 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. A minimum of two high line power supplies or three low line must be
installed in the switch for non-redundant operation. 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.
NOTE: After powering off a power supply, wait for at least 60 seconds before turning it back on.
To remove an AC power supply from an EX9253 switch (see
1. Switch off the dedicated customer-site circuit breaker for the power supply, and remove the power
cord from the AC power source. Follow the instructions for your site.
2. Verify that the input status LED on the power supply is not lit.
3. Wrap and fasten one end of the ESD wrist strap around your bare wrist, and connect the other end
of the strap to the ESD point on the switch.
4. Remove the power cord from the AC appliance inlet on the AC power supply faceplate.
5. Press the ejector lever on the side of the AC power supply to disconnect the power supply from the
chassis.
).
"EX9253 Power System"
Figure 46 on page 125):
Prevention of
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