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Cisco Catalyst 4900M Switch Installation Guide
78-18350-02
Chapter 3 Installing the Switch
Removing and Replacing the Power Supply
Removing and Replacing the Power Supply
This section describes how to remove and install the AC and DC-input power supplies. This information
is presented in the following sections:
•Required Tools, page 3-19
•Removing a Power Supply, page 3-19
•Installing a Power Supply, page 3-20
Warning
Hazardous voltage or energy is present on the backplane when the system is operating. Use caution
when servicing.
Statement 1034
Locate your power supply and notice the location of the captive installation screws.
NoteThe power supplies are hot-swappable, so in redundant mode you will not need to power down the switch
to replace most power supplies. In combined mode some slots may lose power during power supply
replacement.
Required Tools
You will need a flathead or Phillips screwdriver or 5/16” nut driver or socket to perform these
procedures.

Removing a Power Supply

Follow these steps to remove a power supply:
Step 1Set the power switch to the off (O) position.
CautionFor DC installations, the DC power source or panel breaker should be powered down before
disconnecting input power cables from the 1000W DC power supply.
Step 2Disconnect the power cord or cords from the power supply being removed.
Step 3Loosen the captive screws.
CautionUse both hands to remove a power supply.
Step 4Grasp the power supply handles and pull the power supply out an inch to unseat the backplane
connections. Place one hand underneath to support the bottom of the power supply.
Step 5Pull the power supply out of the bay and set it aside.