Installation Manual

Tsunami Multipoint Version 1.3 Installation Guide
Lightning
You should always consider the potential for lightning damage to radio equipment when planning a
wireless link. A variety of lightning-protection and grounding devices are available for use on buildings,
towers, antennas, cables, and equipment that could be damaged by a lightning strike, whether located
inside or outside the site.
Lightning protection requirements are based upon the exposure at the site, the cost of link down-time,
and local building and electrical codes. If the link is critical and the site is in an active lightning area,
attention to thorough lightning protection and grounding is critical.
Lightning Protection
To provide effective lightning protection, install antennas in locations that are unlikely to receive direct
lightning strikes, or install lightning rods to protect antennas from direct strikes. Make sure that cables
and equipment are properly grounded to provide low-impedance paths for lightning currents. Install
surge suppressors on adjacent telephone lines and power lines.
Users should provide additional lightning protection for cables leading to the wireless radio as well as to
and from the power supply in regions that have extreme lightning occurrences. This optional lightning
protection should be placed at points close to where the cable passes through the bulkhead into the
building, as well as near the BSU/SU. A grounding screw is provided on the BSU and SU.
For indoor applications, you can use the Erico LAN-RJ45 Local Area Network Protector (see Erico’s web
site, http://www.erico.com
for information); for outdoor applications, you can use lightning protectors
from PolyPhaser (see the Polyphaser web site, http://www.polyphaser.com
).
See “Appendix E. Lightning Protection Recommendations” on page 70 for more information.
Category 5 Cable
When the entire power and Ethernet cable is encased in steel conduit from the building entrance to the
radio, no surge arrestors are required. Otherwise, each power and Ethernet cable requires one surge
arrestor within two feet of the building entrance.
Interference and How to Avoid It
An important part of planning your broadband fixed wireless system is the avoidance of interference.
Interference can be caused by effects outside the system. Good RF planning can overcome most
interference challenges.
Note: The Tsunami Multipoint product line includes a BSU that provides spectrum shielding. This BSU model can
reject interference at the uplink location. If interference from other systems is a problem, Proxim
recommends you use a BSU equipped with this feature.
Chapter 1. Site Planning 10
CPN 63179 Issue Date: 01/24/03