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

MINIMUM SITE GROUNDING (EARTHING) REQUIREMENTS CHAPTER 4: EXTERNAL GROUNDING (EARTHING)
FIGURE 4-30 HIGH-COMPRESSION CONNECTORS AND TYPICAL CRIMPING TOOLS
4.7 MINIMUM SITE GROUNDING (EARTHING) REQUIREMENTS
This section provides the minimum grounding (earthing) requirements for installing a grounding
electrode system at a communications site and for bonding site equipment to the grounding electrode
system. Reasonable attempts shall be made to achieve the grounding electrode system resistance design
goal, as defined in “Grounding (Earthing) Electrode System Resistance Requirements” on page 4-46
The requirements for installing a typical grounding electrode system are as follows:
• Perform a soil resistivity test at the site as described in Appendix B, “Soil Resistivity
Measurements”
• Calculate the resistance of a single ground rod as described in “Interpreting Test Results” on
page B-10.
• Determine the resistance requirement of the grounding electrode system, based on the site type
(“Light Duty” or “Standard Duty” site). See “Grounding (Earthing) Electrode System Resistance
Requirements” on page 4-46.
4.7.1 TYPE “A” SITE - LIGHT DUTY
MECHANICAL HYDRAULIC BATTERY-POWERED
• Determine if the single ground rod will meet the minimum 25 ohm requirement. If the single
ground rod does not meet the 25 ohm requirement, an additional ground rod, or other grounding
(earthing) electrode, will be required. See “Type “A” Site Grounding (Earthing)” on page 4-48 for
additional information.
• Install the ground rod(s) as described in “Type “A” Site Grounding (Earthing)” on page 4-48 and
elsewhere throughout this chapter.
NOTE: It is recommended to use two grounding electrodes as the minimum installation, even if 25 ohms is
achieved with a single grounding electrode.
4-44 68P81089E50-B 9/1/05