standards and guidelines for communication sites - Radio And ...

STANDARDS AND GUIDELINES FOR COMMUNICATION SITES SPECIAL GROUNDING (EARTHING) SITUATIONS
TABLE 4-9 STANDARD WIRE SIZES AVAILABLE FOR INTERNATIONAL MARKET
Conductor size in mm 2 csa Conductor size in AWG / MCM
6 10
10 8
16 6
25 4
35 2
50 1/0
75 2/0
95 3/0
120 4/0
150 300 MCM
185 350 MCM
240 500 MCM
300 600 MCM
400 800 MCM
NOTE: Down conductors alone should not be relied on for an effective grounding electrode system. Other
methods listed in this section, such as building and tower ground rings, should also be used to help
achieve an effective grounding electrode system.
• Installation of copper strap radial grounding conductors on the surface of the rocks in all directions
from the tower. The copper straps may be covered with top soil and/or ground enhancing material,
such as conductive concrete. Each copper strap radial should be a different length to help prevent
ringing of the tower during a lightning strike.
IMPORTANT: At sites, such as stone mountain tops, where it is difficult to achieve an effective
grounding electrode system, the need for single-point grounding and transient voltage surge suppression
(TVSS) on all input/outputs is of paramount importance.
68P81089E50-B 9/1/05 4-95