User Manual Part 2
Link CX-24 User’s Manual
Version 1.0 Page 59 February 2004
Use 4 to 6 AWG wire to connect each ground rod to the equipment to be grounded. The cables should be
free of sharp bends. Each ground cable should be at least 2 m in length with at least 1 m separation
between each. Refer to local and national electrical codes to determine acceptable grounding methods.
The Link CX-24 chassis should be directly connected to ground to ensure that it functions correctly. In
most cases, following the local code requirements for grounding and lightning protection will be adequate.
Many of the cables used by YDI have braided rather than solid outer conductors; this type of grounding is
not appropriate. In these cases surge arrestors approved by YDI should be used. For information on
surge arrestors, please contact the YDI Customer Support department.
D-3 Lightning Protection
Radio sites can be particularly prone to lightning strikes by virtue of their normally exposed locations and
the presence of relatively tall antenna support structures.
Reference should also be made to various publications, some of which are listed in the bibliography.
Any site owner or user in doubt about the protection requirements for a particular location should contact
the appropriate authority.
D-3.1 Purposes
The purposes of any protection arrangement should be to:
• Provide a suitable path to ground for the lightning current.
• Ensure adequate bonding between structures and all metalwork on the site and the common
grounding system in order to reduce side flashing.
• Prevent the entry of flashes or surges into the building.
The resistance to ground should be kept to a minimum; a value of less than 10 Ohms is recommended.
Ideally, and most important, the system should be at equal potential across the entire site.
Certain authorities and service providers have their own particular practices that have to be followed
where applicable.
Protection arrangements vary considerably, from very simple sites to complicated sites with multiple
buildings, antenna support structures, and associated equipment. Ensuring adequate protection may also
involve integration with and upgrading of existing systems.
D-3.2 Lightning Conductors
Down conductors, bonding interconnections, ground rings, and radial tapes should be of uninsulated 000
AWG copper cable or solid copper tape with a minimum cross section of 25 mm by 3 mm, with all
connections protected by non-reactive paste.
Protected test points should be included if appropriate, and sacrificial ground lugs should be clearly
marked and easily accessible for periodic inspection.
D-3.3 Grounding Antenna Support Structures
A structure generally acts as its own lightning conductor and, therefore, does not require an additional
conductor from the top to the base. A lightning rod may be required to extend the zone of protection to
equipment mounted on the top of the structure. The lightning rod should extend 2.5 m above the highest
equipment.
It is not possible to provide and guarantee complete protection from the effects of lightning; however,
risks of this sort can be significantly reduced by careful attention to grounding, protection devices, and the
layout of the site itself.