Chapter 2 Preparing for Installation
Site Requirement Guidelines
2-20
Cisco 12006 and Cisco 12406 Router Installation and Configuration Guide
OL-11497-03
Site Wiring
This section presents site wiring guidelines for setting up the plant wiring and
cabling at your site. When planning the location of the new system, consider the
following:
• Electromagnetic interference (EMI)
• Distance limitations for signaling and unshielded conductors

Electromagnetic Interference

EMI can occur between the signals on the wires and external or ambient EMI
fields when the wires are run for any significant distance. Bad wiring practice can
result in radio interference emanating from the plant wiring.
Warning
Strong EMI, especially when it is caused by lightning or radio transmitters, can
destroy the signal drivers and receivers in the Cisco 12006 and Cisco 12406
Router, can create an electrical hazard by conducting power surges through
lines, and can damage the equipment.
To predict and remedy strong EMI, you may need to consult experts in radio-
frequency interference (RFI).
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 when applicable.

Distance Limitations

If wires exceed recommended distances, or if wires pass between buildings, give
special consideration to the effect of a lightning strike in your vicinity. The
electromagnetic pulse (EMP) caused by lightning or other high-energy
phenomena can easily couple enough energy into unshielded conductors to
destroy electronic devices. If you have had problems of this sort in the past, you
may want to consult experts in electrical surge suppression and shielding.