Chassis Cooling - Cisco Catalyst 4900 Series Installation Manual

Chapter 1 Product Overview

Chassis Cooling

Note
Caution
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Table 1-1 LED Functions (continued)
LED Color or State
FAN Off
Green
Red
PS1 and Off
PS2 Green
Red
1. If either LED is green and the other is OFF the power supply is probably not plugged in. If it is
red, the supply is either plugged in and not switched on or it is faulty. It may be necessary to use
the CLI for further status information.
For environmental specifications, see
The hot-swappable system fan tray provides cooling air for the internal chassis
components. The fans exhaust air to the rear, and fresh air is drawn in from the
sides of the chassis.
When the fan tray is removed, internal circuitry is exposed that should not be
touched by tools or fingers. The system should not be left operating without a fan
tray for longer than is necessary to replace a faulty fan tray with a new one.
Figure 1-8 shows the direction of airflow going in and out of the switch.
Description
No power to the switch or fans (the tray may
not be plugged in especially if one or more of
the power supplies status LED is green)
Fan tray operational
Fault detected
No power to the PS
1
Operational
Fault detected or the on/off switch is set to
off while the power supply is plugged in
Chapter 2, "Site Planning."
Catalyst 4900 Series Switch Installation Guide
Switch Components
1-11