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 (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 Rack-Mounting and Air Flow Clearance Guidelines, page 1-9for details on air flow clearance requirements for installation in an enclosed 4-post rack.

Cisco ASR 9001 and Cisco ASR 9001-S Routers Hardware Installation Guide

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Cisco Systems ASR 9001-S manual Site Wiring Guidelines, Chassis Air Flow Guidelines