Equipment Rack Configuration; Ventilation Considerations - Cisco ASR 5000 Series Installation 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 ft.) 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:
does not hinder air flow at any of the intake or exhaust vents. Additionally, ensure that the environmental control system
(HVAC) allows the system to function within the required limits.

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 figure below, the lower fan tray pulls ambient air inward from the front and side intake vents located at
the bottom of the chassis. The air is pushed upwards through the system and absorbs heat as it passes over system
components.
Total air flow exiting the chassis is approximately:
 275CFM (7.8 cubic meters/minute) – Low fan speed
 565CFM (16 cubic meters/minute) – High fan speed
The upper fan tray pulls the heated air up through the chassis. The heated air exits through the side and rear exhaust
vents located at the top of the chassis.
▄ ASR 5000 Installation Guide
66
When planning chassis installation, take care to ensure that the equipment rack or cabinet hardware
Chassis Installation