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

GROUNDING (EARTHING) SYSTEM COMPONENTS AND INSTALLATION REQUIREMENTS CHAPTER 5: INTERNAL GROUNDING (EARTHING)
Tower Ground Radial with ground rods at
maximum of 4.9 m (16 ft) intervals.
Typically 3 radials at different lengths.
Ice Bridge / Cable Support
Electrical
Grounding
Electrode
Electrical Service
Main Disconnect
Interior MGB
The SSGB provides a single termination point for all internal ground bus conductors, internal perimeter
ground bus conductors, or equipment grounding conductors within a communications subsystem
equipment room or area as defined herein. By having all equipment and ancillary support apparatus
within the communications system equipment area bonded to a SSGB, differences in potential between
communications system components are minimized and the probability of personal injury, system
failure, or equipment damage greatly reduced.
A SSGB shall not be used when the associated equipment is located in a separate shelter or building,
even if the shelter or buildings are adjacent to one another. A shelter added as a permanent attachment to
an original building or shelter, which receives AC power from the same electrical service as the original
building or shelter, is not considered a separate shelter or building for the purpose of this paragraph. See
Figure 5-11 for an example of some acceptable SSGB configurations.
Tower
Equipment
Room
Ground Rods
(16 mm (0.625 in) x 2.4 m (8 ft) minimum)
Tower Ground Ring with
ground rods at maximum of
4.9 m (16ft) separation.
Tower Ground Bus Bar
Exterior EGB
Ground Bus
Extension
Conductors
External Ground
System
Internal Perimeter Ground
Bus Conductor
Corridor
Ground Bus
Conductors Cable Runway Bonding Jumpers.
Typical at each section connection point.
Bond mounting rail for each piece of equipment
to SSGB with an Equipment Grounding
Conductor. (typical each position)
FIGURE 5-11 EXAMPLE OF SSGB CONFIGURATION
Notes:
No antennas, transmission lines, data, control, or
telephone cables are shown.
No electrical distribution or TVSS devices are shown.
Cable Tray Equipment
Grounding Conductor
Internal Ground
System
Dispatch Center
A SSGB may be installed in an assembly of communications equipment cabinets or at a network
operator position as necessary to provide an effective bonding point for all equipment grounding
conductors. Installation of a single rack, cabinet or chassis within a room or area does not require the
installation of a SSGB as defined in this section, though one may be installed if desired.
5-16 68P81089E50-B 9/1/05
SSGB