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

STANDARDS AND GUIDELINES FOR COMMUNICATION SITES GROUNDING (EARTHING) FOR SMALL, LARGE, AND MULTI-STORY BUILDINGS
NOTE: All grounding and bonding connectors shall be listed for the application by a nationally recognized
testing laboratory (ANSI-J-STD-607-A-2002).
When a grounding equalizer conductor is bonded to a main SSGB, the grounding equalizer conductor
shall be connected to the SSGB using exothermic welding, compression two-hole lugs, or irreversible
compression type connections.
5.7.5 ITEMS TO BE BONDED TO THE INTERNAL GROUND (EARTH)
SYSTEM
See ANSI-J-STD-607-A-2002 for additional information. When a electrical power panelboard is
located in the same room or space as the MGB or SSGB, that panelboard's alternating current
equipment ground (earth) (ACEG) bus or the panelboard enclosure shall be effectively bonded to the
MGB or the SSGB with a 16 mm 2 csa (#6 AWG) or coarser grounding conductor. Where a panelboard
for the communications equipment is not located in the same room or space as the SSGB, consideration
should be given to bonding panelboard ACEG bus or the panelboard enclosure back to the SSGB with a
properly sized grounding conductor. In all cases the grounding conductor should be sized according to
its length in accordance with the requirements in Table 5-5 on page 5-29.
All metallic raceways or cable trays for telecommunication cabling that is located within the same room
or space as the MGB or a main SSGB shall be effectively bonded back to the MGB or the SSGB with a
16 mm 2 csa (#6 AWG) or coarser, grounding conductor as described in paragraph 5.5.1.5 on page 5-45.
When structural building steel is readily accessible within the room of a MGB or main SSGB, the MGB
and/or SSGB shall be effectively bonded to the vertical steel frame with a 16 mm 2 csa (#6 AWG) or
coarser, grounding conductor by following bonding methods in paragraphs 5.4.2 on page 5-34 and 5.4.3
on page 5-36. If the structural steel frame is external to the room or space of the MGB or SSGB and
readily accessible, the steel frame should be bonded back to the MGB or SSGB with a 16 mm 2 csa (#6
AWG) or coarser, grounding conductor as described above. The MGB or SSGB grounding conductor
shall be bonded to the vertical steel column, routed downward toward the earth’s surface. When
practicable because of shorter conductor runs and where horizontal steel members of the building frame
are permanently and electrically bonded to the vertical column members, the SSGBs may be bonded to
the horizontal members. The grounding conductor should be sized according to its length as shown in
Table 5-5 on page 5-29, and if a bend is required in the grounding conductor, minimum bending radius
and angle shall be adhered to.
The telecommunications primary SPD grounding conductor shall be connected to the MGB using the
shortest and straightest routing path practical. A minimum separation distance of 305 mm (1ft) shall be
maintained between other cable groups even if the conductor is routed inside a metallic conduit. See
paragraph 5.5.1.8.2 on page 5-50 for additional information.
68P81089E50-B 9/1/05 5-61