under the walk surface within 75 mm (3 in.), bonded to all metal structures and fixed nonelectrical equipment that may become energized, and connected to the electrical grounding system to prevent a difference in voltage from developing within the plane.
810.1 Scope. This article covers antenna systems for radio and television receiving equipment, amateur radio transmitting and receiving equipment, and certain features of transmitter safety. This article covers antennas such as multielement, vertical rod, and dish, and also covers the wiring and cabling that connects them to equipment. This article does not cover equipment and antennas used for coupling carrier current to power line conductors.
685.1 Scope. This article covers integrated electrical systems, other than unit equipment, in which orderly shutdown is necessary to ensure safe operation. An integrated electrical system as used in this article is a unitized segment of an industrial wiring system where all of the following conditions are met:
(1) An orderly shutdown is required to minimize personnel hazard and equipment damage.
FPN: Rules that are followed by a reference in brackets contain text that has been extracted from NFPA 90A-2002, Standard for the Installation of Air- Conditioning and Ventilating Systems. Only editorial changes were made to the extracted text to make it consistent with this Code.
820.1 Scope. This article covers coaxial cable distribution of radio frequency signals typically employed in community antenna television (CATV) systems.
Notes:
1. These diagrams are intended to be a means of identification for photovoltaic system components, circuits, and connections.
2. Disconnecting means required by Article 690, Part III, are not shown.
3. System grounding and equipment grounding are not shown. See
Article 690, Part V.
signal circuits. The NIU may also contain primary and secondary protectors.
FPN: A typical single-family network-powered communications circuit consists of a communications drop or communications service cable and an NIU and includes the communications utility's serving terminal
692.3 Other Articles. Wherever the requirements of other articles of this Code and Article 692 differ, the requirements of Article 692 shall apply, and, if the system is operated in parallel with a primary source(s) of electricity, the requirements in 705.14, 705.16,
705.32, and 705.143 shall apply.
692.4 Installation.
(A) Fuel Cell System. A fuel cell system shall be permit-
(A) Conduct or Witness Test. The authority having juris- diction shall conduct or witness a test of the complete system upon installation and periodically afterward.
(B) Tested Periodically. Systems shall be tested periodically on a schedule acceptable to the authority
FPN: Rules that are followed by a reference in brackets contain text that has been extracted from NFPA 497-
2004, Recommended Practice for the Classification of
Flammable Liquids, Gases, or Vapors and of Hazardous
(Classified) Locations for Electrical Installations in
Chemical Process Areas. Only editorial changes were
made to the extracted text to make it consistent
with this Code.
