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

STANDARDS AND GUIDELINES FOR COMMUNICATION SITES AC POWER
• The site electric meter shall be located where it is visible and accessible to power company meter
readers and shall comply with all applicable codes and/or power company requirements.
• Meter access by power company personnel should be considered when determining meter location
(especially where a fence is involved). (See NFPA 70-2005, Article 100 and Article 230 for details
regarding locations and service conductors.)
NOTE: The following refers to the Main Disconnect for the separately derived system feeding the equipment
room. The Main Disconnect may not be located in the same building as the equipment (a meter farm at
a tower site, for example). This makes the panel in the building with the equipment a sub-panel and not
the main disconnect.
• At all sites, there is either or both a main service disconnect and a fused disconnect. A main service
disconnect may be located at a meter location away from the building. A main disconnect located
within the shelter, equipment room or area may be fed by a feeder circuit originating at a main
service disconnect located in an electrical room in a different location in the building or even a
separate building. Typically, the neutral and ground conductors are bonded in the main service
disconnect. When the main service disconnect is located remotely from the equipment room or
area, a separately derived system should be installed in the equipment room. (See NFPA 70-2005,
Article 250.30 and 250.32 for additional information.)
One of the reasons for the separately derived system is to reestablish the neutral/ground bond,
thereby improving the effectiveness of normal mode suppression.
NOTE: See Table 7-1 on page 7-7 and associated Chapter 7 figures for additional information regarding
connections for separately derived systems.
• A fused disconnect shall always be installed before all other panels and equipment, including a
generator transfer switch. (See NFPA 70-2005, Article 445.18 for additional information.)
• For a stand-alone equipment shelter, the main disconnect shall be located on the same wall as the
coaxial cable entry port, the telephone entry point, and the MGB. If it is not possible to locate these
components on the same wall, then these components shall be located on an adjacent wall as close
together as possible. (See IEEE 1100-1999 Section 8.3.2.1.2 for additional information.)
• The main bonding jumper shall be installed between the neutral bus and the ground bus within the
main service disconnect. This is to ensure an effective low-impedance neutral-to-ground bond
connection. (See NFPA 70-2005, Article 250.24(B) for additional information.)
• Self-tapping or sheet metal type screws shall not be used for attaching ground or grounding
conductors to any surface. (See NFPA 70-2005, Article 250.8 for additional information.)
• Paint, enamel, lacquer, or other nonconductive coatings shall be removed from threads and surface
areas where connections are made. (See NFPA 70-2005, Article 250.12 for additional information.)
68P81089E50-B 9/1/05 6-3