Lightning and AC Power Fault Interference
If signal wires exceed the recommended cabling distances, or if signal wires pass between buildings, you
should consider the effect that a lightning strike in your vicinity might have on the Cisco ASR 903 Router.
The electromagnetic pulse (EMP) generated by lightning or other high-energy phenomena can couple enough
energy into unshielded conductors to damage or destroy electronic equipment. If you have previously
experienced such problems, you should consult with RFI and EMI experts to ensure that you have adequate
electrical surge suppression and shielding of signal cables in your Cisco ASR 903 Router operating environment.
Rack-Mounting Guidelines
The following sections provide guidelines for rack-mounting the Cisco ASR 903 Router:
Precautions for Rack-Mounting
The following rack-mount guidelines are provided to ensure your safety:
• Do not move large racks by yourself. Due to the height and weight of a rack, a minimum of two people
are required to accomplish this task.
• Ensure that the rack is level and stable before extending a component from the rack.
• Ensure that proper airflow is provided to the components in the rack.
• Do not step on or stand on any component or system when servicing other systems or components in a
rack.
• When mounting the Cisco ASR 903 Router in a partially filled rack, load the rack from the bottom to
the top, with the heaviest component at the bottom of the rack.
• If the rack is provided with stabilizing devices, install the stabilizers before mounting or servicing the
unit in the rack.
Rack Selection Guidelines
The Cisco ASR 903 Router can be mounted in most two-post or four-post, 19-inch equipment racks that
comply with the Electronic Industries Association (EIA) standard for equipment racks (EIA-310-D 19-inch).
The rack must have at least two posts with mounting flanges to mount the chassis.
When mounting a chassis in any type of rack equipment, ensure that the inlet air to the chassis does not exceed
65°C.
Caution
The distance between the center lines of the mounting holes on the two mounting posts must be 18.31 inches
± 0.06 inch (46.50 cm ± 0.15 cm). The rack-mounting hardware included with the chassis is suitable for most
19-inch equipment racks.
Consider installing the Cisco ASR 903 Router in a rack with the following features:
• Network Equipment Building System (NEBS) compliant, 19-inch (48.3 cm) wide rack.
• EIA or European Telecommunications Standards Institute (ETSI) hole patterns in the mounting rails.
The required mounting hardware is shipped with the Cisco ASR 903 Router. If the rack that you plan to
install the system in has metric-threaded rails, you must provide your own metric-mounting hardware.
• Perforated top and open bottom for ventilation to prevent overheating.
• Leveling feet for stability.
Cisco ASR 903 and ASR 903U Aggregation Services Router Hardware Installation Guide
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Preparing for Installation
Lightning and AC Power Fault Interference