Chapter 1 Cisco XR 12404 Router Overview

Fan Tray Assembly

The status LEDs on the DC PEM provide information about the current operational status of the power supply. Table 1-5summarizes the function of these indicators.

Table 1-5

DC-Input PEM LED Indicators

 

 

 

 

LED Label

 

Color

Function

 

 

 

 

Output OK

 

Green

PEM is powered on and operating normally.

 

 

 

 

Input OK

 

Green

DC power is present at the PEM input and

 

 

 

within the specified limits.

 

 

 

 

Output Fail

 

Amber

Indicates a failure in the PEM.

 

 

 

 

Power Distribution

The backplane distributes power through the Cisco XR 12404 router and to all cards in the card cage. The PEM converts AC power source into –48 VDC. When directed by the route processor or by MBus software, the MBus module turns on the DC-DC converter; the –48 VDC is converted into +2.5 VDC, +3.3 VDC and +5 VDC for all internal voltages required by the cards.

Power for the fan tray assembly is supplied directly from the backplane. An internal fan tray assembly controller card converts –48 VDC into DC voltage that powers the fans.

Fan Tray Assembly

The Cisco XR 12404 router is equipped with a fan tray assembly located at the side of the chassis. The fan tray assembly maintains acceptable operating temperatures for the internal components by drawing cooling air across the card cage.

 

Cisco XR 12404 Router Installation Guide

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Cisco Systems XR 12404 manual Fan Tray Assembly, Power Distribution