Service manual

Installation: Pre-Installation Considerations 2-7
2.1.7 Site Grounding and Lightning Protection
2.1.7.1 Site Grounding Lightning Protection Recommendations
IMPORTANT: Proper site grounding and lightning protection are vitally important
considerations. Failure to provide proper lightning protection may result
in permanent damage to the radio equipment.
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 as follows:
• 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, telephone lines, and wires or cables connected to alarms or
sensors located at the site.
• RF Ground
This type of ground is related to the transmission of 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.
• Lightning Ground
Providing adequate lightning protection is critical to a safe and reliable communications site.
Telephone lines, 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 site grounding techniques and lighting protection is not
within the scope of this manual, there are several excellent industry sources for rules and guidelines
on ground and lightning protection at communications sites.
NOTE: Motorola recommends the following reference source:
Motorola Quality Standards Fixed Network Equipment Installation manual, R56
(6881089E50)
2.1.7.2 Equipment Grounding Guidelines
The base station/repeater is equipped with a ground screw located on the rear of the base station/
repeater Power Supply module. This screw is used to connect the base station/repeater to the site
ground point. It is assumed that all telephone lines, antenna cables, and AC or DC power cabling
has been properly grounded and lightning protected by following the rules and guidelines provided in
the above reference.