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

STANDARDS AND GUIDELINES FOR COMMUNICATION SITES GROUNDING (EARTHING) SYSTEM COMPONENTS AND INSTALLATION REQUIREMENTS
• In a small, large or multi-story building, the MGB grounding conductor shall extend from the
MGB to the service equipment (power) grounding electrode system (ANSI-J-STD-607-A-2002).
• Where any of the following exist at a building or structure, they shall be effectively bonded
together to form a common grounding electrode system and the MGB may bond to any point on
this grounding electrode system: a metallic underground water pipe, the metal frame of the building
or structure, concrete-encased electrodes, a ground ring conductor encircling the building or
structure, rod or pipe electrodes and plate electrodes. (See NFPA 70-2005, Article 250.50 and
250.52 for additional information.) See Chapter 4, “External Grounding (Earthing),” for external
grounding electrode system bonding requirements.
MIN. #2
AWG A
GROUND RING
LABEL
BUILDING STEEL
TWO HOLE LUG
P A N I
MIN. #2
AWG A
MIN. #6
AWG A
AC SYSTEM
GROUND
MIN. #2
AWG A
MIN. #2
AWG A
FIGURE 5-10 TYPES OF ACCEPTABLE GROUNDING ELECTRODE SYSTEMS
5.3.2 SUB SYSTEM GROUND (EARTH) BUS BAR
A Sub System Ground Bus Bar (SSGB) may be installed within a generator or power distribution room,
a communications subsystem equipment room or area separate from, but associated with, the main
communications equipment room or area and located within the same building as the MGB. In some
applications the SSGB may be referred to as a telecommunications ground bus bar (TCGB), an isolated
zone ground bus bar (IZGB), an ancillary ground bus bar (AGB), a logic ground bus bar (LGB), a frame
ground bus bar (FGB), a telephone cable ground bus bar (TCGB), or an equipment reference ground
bus bar (ERGB).
68P81089E50-B 9/1/05 5-15
MIN.
#4
CLAMP
PLATE A
ELECTRODE
METAL T L UNDERGROUND W A ATER
PIPE
MIN. 3 M (10 FT) IN EARTH
CONCRETE ENCASED ELECTRODE