Airflow Guidelines for ETSI Rack Installation
When you install a device on a 2 or 4-post rack, the front and rear doors of the cabinet must be removed. We
recommended that you always maintain a minimum clearance distance as mentioned the following.
• Front clearance—5 inches (12.7 centimeters)
• Rear clearance—3.93 inches (10 centimeters)
To mount the chassis in a 4-post enclosed cabinet, ensure a minimum of 3.93 inches (10 centimeters) of
clearance on each side of the chassis.
Floor Loading Considerations
Ensure that the floor under the rack supporting the chassis is able to support the combined weight of the rack
and all the other installed equipment.
For additional information about floor loading requirements, see the
Building System (NEBS) Requirements: Physical Protection
document.
Site Power Guidelines
The chassis has specific power and electrical wiring requirements. Adhering to these requirements ensures
reliable operation of the system. Follow these precautions and recommendations when planning your site
power for the chassis:
• The redundant power option provides a second, identical power supply to ensure uninterrupted power
supply.
• Connect each power supply to a separate input power source. Otherwise, it results in total power failure
to the system due to a fault in the external wiring or a tripped circuit breaker.
• To prevent loss of input power, ensure that the maximum load on each circuit is within the current ratings
of the wiring and the breakers.
• Check the power at your site before installation, and periodically after installation, to ensure that you are
receiving clean power. If necessary, install a power conditioner.
• Provide proper grounding to avoid personal injury and damage to the equipment due to power surges or
lightning striking power lines. The chassis ground must be attached to a central office or other interior
ground system.
This product requires short-circuit (overcurrent) protection to be provided as part of the building installation.
Install only in accordance with national and local wiring regulations.
Caution
The chassis installation must comply with all the applicable codes, and is approved for use with only copper
conductors. The ground bond-fastening hardware must be compatible and preclude loosening, deterioration,
and electrochemical corrosion of hardware and joined material. Attachment of the chassis ground to a central
office or other interior ground system must be made with a 6-AWG gauge wire copper ground conductor.
Note
Cisco ASR-920-20SZ-M Aggregation Services Router Hardware Installation Guide
18
Prepare for Installation
Airflow Guidelines for ETSI Rack Installation
