Motorola DR 3000 - Manual (Page 10)

6866576D02 June 12, 2007
Pre-Installation Considerations: Site Grounding and Lightning Protection 1-3
1.6 Site Grounding and Lightning Protection
One of the most important considerations when designing a communications site is the ground and
lightning protection system. While proper grounding techniques and lightning protection are closely
related, the general category of site grounding may be divided into the following section.
1.6.1 Electrical Ground
Ground wires carrying electrical current from circuitry or equipment at the site is included in the
category of electrical ground. Examples include the AC or DC electrical power used to source
equipment located at the site, and wires or cables connected to alarms or sensors located at the site.
1.6.2 RF Ground
This type of ground is related to the transmission of the radio frequency energy to earth ground. An
example of RF grounding is the use of shielding to prevent or at least minimize the leakage of
unwanted RF transmissions from communications equipment and cables.
1.6.3 Lightning Ground
Providing adequate lightning protection is critical to a safe reliable communications site. RF
transmission cables, and AC and DC power lines must all be protected to prevent lightning energy
from entering the site building.
Although a comprehensive coverage of the site grounding technique and lightning protection is not
within the scope of this instruction manual, there are several excellent industry sources for rules and
guidelines on ground and lightning protection at communications site.
NOTE: Motorola recommends the following reference source:
Motorola Quality Standards Fixed Network Equipment
Installation Manual R56……………………...……………......................................6881089E50
1.6.4 Equipment Grounding Guidelines
The repeater is equipped with a ground screw located on the rear of the repeater power supply
module. This screw is used to connect the repeater to the site ground point. It is assumed that all
antenna cables, and AC or DC power cabling, has been properly grounded and lightning protected
by following the industry rules and guidelines.
1.7 Power Supply Connections
Refer to 4.1.1 AC Input Power Connection on page 4-1 for the recommended AC input power
connection and to 4.1.2 Ground Connection on page 4-2 for the recommended ground connection.
Proper site grounding and lightning protection are vitally important consider-
ation. Failure to provide proper lightning protection may result in permanent
damage to the radio equipment.
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