Equipment Rack Configuration; Ventilation Considerations - Cisco ASR 5000 series Installation And Administration Manual

▀ Equipment Rack Configuration

Equipment Rack Configuration
The chassis is designed for installation in a standard 19-inch (48.26 cm) equipment rack. Additional rack hardware, such
as extension brackets, may be used to install the chassis in a standard 23-inch (58.42 cm) rack. Each chassis is 24.50
inches (62.23 cm) high. This equates to roughly 14 Rack Mount Units (RMUs: 1 RMU = 1.75 in (4.45 cm).
You can mount a maximum of three chassis in a standard 48 RMU (7 feet) equipment rack or telco cabinet provided that
all system cooling and ventilation requirements are met. A fully-loaded rack with three chassis installed has
approximately 5.5 inches (13.97 cm, 3.14 RMUs) of vertical space remaining.
Caution:
not hinder air flow at any of the intake or exhaust vents. Additionally, ensure that the rack/cabinet hardware, as well as
the ambient environment, allow the system to function within the required limits. Refer to the Ventilation
Considerations section of this chapter for more information.

Ventilation Considerations

Airflow within the system is designed per Telcordia recommendations to ensure the proper vertical convection cooling
of the system.
As shown in the following figure, the lower fan tray pulls fresh air in from the front and side intake vents located near
the bottom of the chassis. The air is forced upwards through the system and cools installed components as it passes over
them. The airflow through the chassis, as measured by the speed of the airflow across the various card slots, maintains
an average of 290 feet per minute (fpm).
The upper fan tray pulls heated air up through the chassis. The air is forced through the side and rear exhaust vents
located near the top of the chassis before it is expelled from the system.
▄ Cisco ASR 5000 Series Aggregation Services Router Installation and Administration Guide
When planning chassis installation, take care to ensure that equipment rack or cabinet hardware does
Chassis Installation
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