Power Distribution; Fan Tray - Cisco 12404 Installation And Configuration Manual

Chapter 1 Product Overview

Power Distribution

Fan Tray

Warning
OL-11636-01
The backplane distributes power through the Cisco 12404 router and to all cards
in the card cage. The PEM converts AC power source into –48 VDC. When
directed by the RP 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.
The Cisco 12404 router is equipped with 1 fan tray 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.
The fan assembly is a sheet metal enclosure containing 7 fans and 2 fan controller
cards (Figure 1-13).
Exhaust from other equipment vented directly into the Cisco 12404 router air
inlet can cause an over-heat condition. Install the router so that it is protected
from a direct flow of hot air from other equipment.
Cisco 12404 Internet Router Installation and Configuration Guide

Fan Tray

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