Fan Tray - Cisco Router 7204 Installation And Configuration Manual

Chapter 1 Product Overview
Physical Description
This product relies on the building's installation for short-circuit (overcurrent) protection. Ensure that a
listed and certified fuse or circuit breaker, 20A minimum 60 VDC, is used on all current-carrying
conductors.
The power OK LED goes off and the power supply will shut itself down when the internal DC voltages
exceed allowable tolerances or the internal temperature of the power supply exceeds allowable
tolerances. The power supply will remain in a shut down state until it is disconnected and reconnected
to the source power, and then restarted with the power switch. The power switch turns the power supply
on and starts the system. For a description of power-supply shutdown conditions and thresholds, refer to
the ""Environmental Monitoring and Reporting Functions" section on page 1-26".

Fan Tray

The fan tray, shown in Figure 1-15, consists of three fans that are enclosed in a metal case. The fan tray
is located in the subchassis and receives –12 VDC through a DC power harness that connects directly to
the router midplane. You must remove the subchassis to access the fan tray.
Figure 1-15 Cisco 7204 Fan Tray
DC power
harness
Alignment
tabs
The fan tray draws cooling air in through the intake vent on the right side of the chassis (when viewing
the router from the front), and moves the air across the internal components and out the exhaust vent on
the left side of the chassis.
Figure 1-16 shows the air flow through the router.
Cisco 7204 Installation and Configuration Guide
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