Technical data

Field Replaceable Unit Removal and Replacement

Power Entry Modules (PEMs) and PEM Fuses

Chapter 1

Power Entry Modules (PEMs) and PEM Fuses

The two 14-Slot Shelf PEMs are located at the lower right and left corners at the rear of the Shelf. The PEM

is a hot-swap unit. Power Entry Module fuses are mounted in the main body of each PEM, and are accessible

only after the respective PEM has been removed from the Shelf.

WARNING Electrical Shock Hazard to Personnel. Although the PEM is a hot swap unit that can be

removed and replaced while the 14-Slot Shelf continues to operate, all input power domains to

the PEM being replaced must be turned off and disconnected before removal.

Removing a Power Entry Module

WARNING Electrical Shock Hazard to Personnel. Power is present at the PEM power terminals unless the

external power source is turned off. Disable/disconnect all power domain circuit breakers in the

OFF (O) position before completing any of the following steps. Failure to follow electrical safety

precautions may result in personal injury.

CAUTION Electrostatic Discharge Hazard. Observe all ESD safety precautions while completing this

procedure. Failure to follow ESD safety precautions could result in damage to the 14-Slot Shelf

and equipment.

To remove a Power Entry Module (PEM) while the 14-Slot Shelf continues to operate using the redundant

PEM, complete the following steps.

For the PEM to be removed do the following:

Step 1. Disable or disconnect all power domain circuit breakers in the OFF (O) position. The 14-Slot Shelf

should continue to operate unless power has been removed from both PEMs.

Step 2. Press and release the H/S (Hot-Swap) button (#1, Figure 1-2) on the PEM to be removed. The blue

hot-swap LED (#2, Figure 1-2) will flash intermittently while the request is being processed by the

Shelf Manager (ShMM). The blue hot-swap LED will be constantly illuminated when it is safe to

remove the PEM.