Technical data

Field Replaceable Unit Removal and Replacement

Power Entry Modules (PEMs) and PEM Fuses

Chapter 1

Step 3. Connect the power cables and return lines, ensuring that each power domain cable and return line

is attached to the correct power terminal lug (Figure 1-2). It may be easier to connect all PEM

cables before actually replacing the PEM into the 14-Slot Shelf chassis.

Step 4. Position the terminal block cover over the terminal block, then tighten the terminal block cover

retaining screws (Figure 1-2).

Step 5. Enable all power supply circuit breakers supplying power to the replacement PEM.

Step 6. The green PEM OK LED (#4, Figure 1-2) should illuminate steadily. This completes the PEM

replacement procedure.

Removing and Replacing Power Entry Module (PEM) Fuses

Power Entry Module (PEM) fuses for power domain input and return lines are mounted in each PEM, and are

only accessible after the PEM is removed from the Shelf.

NOTE A PEM can be removed from the 14-Slot Shelf in hot-swap mode in order to remove and replace

the fuses. The PEM can then be reinstalled while the 14-Slot Shelf continues to operate.

WARNING Electrical Shock Hazard. 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 for only the PEM to be removed 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 and replace one or more fuses in a PEM, complete the following steps:

Step 1. Disable or disconnect all power supply domain circuit breakers in the OFF (O) position for the PEM

to be removed that has the fuses that must be replaced. The 14-Slot Shelf should continue normal

operation if desired with power supplied by the redundant PEM.

Step 2. Remove the respective PEM, following the removal procedures provided above.

Step 3. Remove and replace PEM fuses as required. Grasp each fuse and remove it by pulling upward.

Press each replacement fuse into its mounting position by pressing down (see Figure 1-3).