By Mike Holt

Chapter 8, while important, has only four Articles:

• Article 800: Communications circuits. The focus is on wiring.
• Article 810: Radio and television equipment. The focus is on antenna circuits.
• Article 820: Community antenna television and radio distribution systems. The focus is on coaxial cable circuits.
• Article 830: Network-powered broadband communications systems. The focus is on systems that use power from the network.

We will look at each of these in turn. You will notice the primary themes are cable protection and proper grounding.

Article 800. Communication Circuits

This Article has its roots in POTS (Plain Old Telephone System). Consequently, it addresses telephone wiring and similar or related systems that use twisted-pair wiring. Here are some key points to remember about Article 800:

• Do not attach incoming cables to the service entrance power mast.
• It is critical to determine the "point of entrance" for these circuits.
• You must ground the primary protector as close as practicable to the point of entrance.
• Keep in mind that the purpose of grounding is to provide unwanted current a way to get back to the source. This purpose dictates several other requirements, such as keeping the primary protector grounding conductor straight and as short as possible.
• If you locate cables above a suspended ceiling, route and support them to allow access via panel removal.
• Keep these cables separated from lightning-protection circuits.
• If you install cables in a Chapter 3 raceway, you must do so in conformance with the BICSI Cabling Installation Manual.
• Special labeling and marking provisions apply-follow them carefully.

Article 810. Radio and Television Equipment

This Article has its roots in wireless communications. Consequently, it addresses transmitter and receiver equipment-and the wiring and cabling that is part of the systems that equipment serves. Here are some key points to remember about Article 800:

• Avoid contact with conductors of other systems. In our study, we'll explain what this means and why it is so important.
• Do not attach antennas or other equipment to the service entrance power mast.
• If you don't ground the mast properly, you risk total destruction of the mast by voltage surges caused by nearby lightning strikes.
• Keep in mind that the purpose of grounding is to provide unwanted current a way to get back to the source. This purpose dictates several other requirements, such as keeping the grounding conductor straight and protecting it from physical damage.
• If you don't bond the mast properly, you risk flashovers and possible electrocution.
• Keep in mind that the purpose of bonding is to prevent a difference of potential between metallic objects or other conductive items, such as swimming pools. Thus,
• Article 810 provides several different bonding requirements.
• Clearances are critical. Article 810 provides extensive clearance requirements. For example, it provides separate clearance requirements for indoors and outdoors.

Article 820. Community Antenna Television and Radio Distribution Systems

This Article focuses on the distribution of television and radio signals within a facility or a property via cable, rather than their transmission or reception via antenna. These signals are limited-energy, but they are high-frequency.

• As with Article 800, you must determine the "point of entrance" for these circuits.
• You must ground the incoming cable as close as practicable to the point of entrance.
• If you locate cables above a suspended ceiling, route and support them to allow access via panel removal.
• Clearances are critical. Article 820 provides extensive clearance requirements. For example, Article 820 requires at least 6 feet of clearance between coaxial cable and lightning conductors.
• If you use a separate grounding electrode, you must run a bonding jumper to the power grounding system.

Article 830 Network-Powered Broadband Communications Systems

An introduction does not make sense, here. - Mark L.

Understanding the NEC, Volume 2 Workbook — 2002

Understanding the National Electrical Code - Volume 2, 2002 Edition was written to provide insite into and an understanding of, many of the technical rules of the NEC. This book covers Articles 500-830. Subjects include: Hazardous (Classified) Locations, Motor Fuel Dispensing Facilities, Health Care Facilities, Manufactured Wiring Systems, Swimming Pools, Fountains and Similar Installations, Emergency Systems, Optical Fiber Cables and Raceways and more. Product Code: 02UNWB2 Table of Contents Sample Graphic