Electromagnetic Interference; Radio Frequency Interference; Lightning And Ac Power Fault Interference; Rack-Mounting Guidelines - Cisco ASR 903 Hardware Installation Manual

Rack-Mounting Guidelines

The following sections describe sources of interference and how to minimize its effects on the Cisco ASR
903 Router system.

Electromagnetic Interference

All equipment powered by AC current can propagate electrical energy that can cause EMI and possibly affect
the operation of other equipment. The typical sources of EMI are equipment power cords and power service
cables from electric utility companies.
Strong EMI can destroy the signal drivers and receivers in the Cisco ASR 903 Router and even create an
electrical hazard by causing power surges through the power lines into installed equipment. These problems
are rare but could be catastrophic.
To resolve these problems, you need specialized knowledge and equipment that could consume substantial
time and money. However, you can ensure that you have a properly grounded and shielded electrical
environment, paying special attention to the need for electrical surge suppression.
For information about the electrode magnetic compliance standards supported on the Cisco ASR 903 Router,
see Regulatory Compliance and Safety Information for the Cisco ASR 903 Router.

Radio Frequency Interference

When electromagnetic fields act over a long distance, radio frequency interference (RFI) may be propagated.
Building wiring can often act as an antenna, receiving the RFI signals and creating more EMI on the wiring.
If you use twisted-pair cable in your plant wiring with a good distribution of grounding conductors, the plant
wiring is unlikely to emit radio interference. If you exceed the recommended distances, use a high-quality
twisted-pair cable with one ground conductor for each data signal.

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
• 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.
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are required to accomplish this task.
Preparing for Installation