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Cisco ASR 9001 and Cisco ASR 9001-S Routers Hardware Installation Guide
OL-26701-02
Chapter 1 Preparing for Installation
Site Requirement Guidelines
Site Wiring Guidelines
When planning the location of the router, consider distance limitations for signaling, electromagnetic
interference (EMI), and connector compatibility. If the wiring is run for any significant distance in an
electromagnetic field, interference can occur between the field and the signals on the wires. Poor wiring
can cause:
•Radio interference emanating from the wires.
•Strong EMI, especially when caused by lightning or radio transmitters. EMI can destroy the signal
drivers and receivers in the router, and can even create an electrical hazard by conducting power
surges through lines and into equipment.
Note To predict and remedy strong EMI, you may need to consult with radio frequency interference
(RFI) experts.
Site wiring is unlikely to emit radio interference if you use twisted-pair cable with good distribution of
grounding conductors. Use a high-quality twisted-pair cable with one ground conductor for each data
signal, when applicable.
Give special consideration to the effect of lightning strikes in your vicinity, especially if the wiring
exceeds recommended distances, or if it passes between buildings. The electromagnetic pulse (EMP)
caused by lightning or other high-energy phenomena can easily induce enough energy into unshielded
conductors, and destroy electronic devices. If you have experienced EMP problems in the past, you may
want to consult experts in electrical surge suppression and shielding.
Most data centers cannot resolve infrequent, but potentially catastrophic, problems without pulse meters
and other special equipment. In addition, these problems can take a great deal of time to identify and
resolve. We recommend that you take the necessary precautions to avoid these problems by providing a
properly grounded and shielded environment, with special attention to issues of electrical surge
suppression.
Chassis Air Flow Guidelines
Cool air is circulated through the Cisco ASR 9001 Router by one fan tray located along the right side of
the router (see Figure 1-5).
The fan tray maintains acceptable operating temperatures for the internal components by drawing in cool
air through the vents, and circulating the air through the chassis. Each power supply is also equipped
with fans that draw cool air into the front of the power supply and force warm air out of the air exhaust.
Note See the “Rack-Mounting and Air Flow Clearance Guidelines” section on page 1-8 section for details on
air flow clearance requirements for installation in an enclosed 4-post rack.