Table of Contents
Advertisement
Prepare for Installation
• < 15 to 85% RH
Physical Characteristics
To set the device at its proper location, be familiar with its physical characteristics.
Airflow Guidelines
Cool air is circulated through the chassis by fans that are located along the back of the device.
The internal fans maintain acceptable operating temperatures for the internal components by drawing in cool
air through the vents and circulating that air through the chassis.
The direction of airflow is from front-to-back.
To ensure adequate airflow through the equipment rack, we recommend that you always maintain a minimum
clearance distance as mentioned in the following specifications.
• Front clearance—5 inches (12.7 centimeters)
• Rear clearance—3.93 inches (10 centimeters)
Note the following points:
• When installing chassis in a back-to-back position with another device, ensure a minimum of 3.93 inches
• An over-temperature condition may occur within the rack, if airflow through the rack and the device is
• Ensure that the site is dust free. Dust tends to clog the device fans, reducing the flow of cooling air
• Enclosed racks must have adequate ventilation. Because each device generates heat, ensure that the racks
• When mounting a chassis on an open rack, ensure that the rack frame does not block the exhaust fans.
• When a rack-installed equipment fails, especially equipment on an enclosed rack, if possible try operating
• Avoid installing the chassis in a location in which the chassis air intake vents may draw in the exhaust
Caution
When mounting the device on any type of rack equipment, ensure that the temperature of inlet air to the device
does not exceed the specified operating temperature limits of the product.
(10 centimeters) airflow clearance between them. Also, ensure that the device behind the chassis is not
installed in a way that it blows air into the chassis.
restricted, or if the air that is drawn into the rack is warm.
through the equipment rack and the devices that occupy it, thus increasing the risk of an over-temperature
condition.
are not congested. An enclosed rack must have louvered sides and a fan to provide cool air. Heat that is
generated by the equipment near the bottom of the rack may be drawn upward into the intake ports of
the equipment above.
the equipment by itself. Power off all other equipment on the rack (and in adjacent racks) to give the
device maximum cooling air and clean power.
air from an adjacent equipment. Consider how the air flows through the device; the airflow direction is
from front to back, with ambient air drawn in from the vents located on the sides of the chassis.
Cisco ASR-920-20SZ-M Aggregation Services Router Hardware Installation Guide
Physical Characteristics
17
Advertisement
Table of Contents
