User Manual Part 2
Link CX-24 User’s Manual
Version 1.0 Page 58 February 2004
Appendix D - Grounding and Lightning Protection
This appendix explains how to properly set up the Link CX-24 radio for grounding and lightning protection.
D-1 Overview
When used in telecommunications, good grounding practices have some direct benefits that can help
users maximize system uptime as well as ensure the safety of those people working on the system.
Among these benefits are:
• Protection of personnel from electric shock and fire hazards
• Reduction of radiated and conducted electromagnetic susceptibility
• Improved system tolerance to discharge of electrostatic energy and lightning interference
• Minimized service interruptions and service damage
No practice or formula can completely eliminate the above risks, but YDI believes that good grounding
and bonding practices can significantly reduce the risk of many of these hazards. This appendix includes
a bibliography that contains several publications that are readily available and provide detailed
information on many aspects of grounding systems and their design, implementation, measurement, and
maintenance.
Please note that every telecommunication site is unique and must be evaluated accordingly. The
following information is provided for generic reference and educational purposes only. The grounding
plans and practices for a given site should be established and implemented only by trained professionals,
working in accordance with local practices and regulations.
YDI strongly recommends that you install a Transtector Lightning Arrestor or equivalent at the cable entry
to the Ethernet, Power, and/or DS-3 equipment structure.
D-2 Grounding
D-2.1 Making a Grounding Plan
A grounding plan should be developed at the outset of site design to provide the best grounding
procedures and to minimize ground loop currents. Grounding should be achieved by connecting the outer
conductors of the cables through a large-section copper strap to a central grounding point, and the size of
the conductor should be increased as each branch path is added. The final conductor should be
connected directly to the grounding system. For a radio site, a single copper grounding rod is insufficient,
because its impedance is likely to be too high.
D-2.2 Grounding Buildings
Ideally, a ground ring should surround the building and be connected to individual grounds associated
with feeder entry, antenna support structure, the building lightning conductor, the equipment room, the
main AC supply, and other facilities. Each connection should be made by the most direct route to
minimize interaction between the different grounding functions.
The ground ring should consist of copper cable or tape with electrodes two meters or longer, buried to a
depth of 0.6 m and at a distance from the building not to exceed 1 m.
Buildings may require lightning rods if they are not within the zone of another protected structure. To
construct a good ground, ground rods should penetrate the earth to a depth of about 2 m (6 feet).
Where the ground is in rocky terrain, make sure that the ground rods penetrate into loose soil. In sandy
soil, use more ground rods to make sure that the ground has sufficient contact with water-bearing
material.