NEC 800 and 820 for the Journeyman Exam: Communications and CATV Cable Entering a Building, Clearances and Bonding

Tsai Electro is an independent learning site. Not affiliated with TDLR, PSI or NFPA. We explain the ideas in our own words and do not reproduce NEC text. Check every rule and table value in your own 2026 NEC, and follow your supervisor and the local inspector.

How Chapter 8 is arranged now

The 2026 NEC reorganized this chapter. Chapter 8 now covers communications systems outside and entering buildings, and it is no longer independent of the rest of the Code; 90.3 explains how it relates to Chapters 1 through 4. Article 805 is gone, and interior communications wiring moved to Chapter 7. If your study notes come from the 2023 edition, update them:

Article	System
800	General requirements for communications systems outside and entering buildings
810	Radio and television antenna equipment (NEC 810.1)
820	Community antenna television (CATV) and radio distribution, the coaxial cable systems (NEC 820.1)
830	Network-powered broadband communications systems (NEC 830.2)

For a question about cable TV coaxial cable entering a building, start with the Article 800 entrance rules, then check Article 820 for what is specific to CATV. If the question is about wiring farther inside the building, look in Chapter 7. Low-voltage control and fire alarm circuits are also Chapter 7 subjects; see NEC 725 and 760.

Outside the building: overhead and underground

• On poles and in span. Where practicable, communications wires and cables run below electric light and power conductors, with the separation the section sets (NEC 800.44(A)).
• Over roofs. Cables keep at least 8 feet above roofs they pass over, with exceptions such as for some roof slopes and for short runs over an overhang near the point of attachment; read the exceptions (NEC 800.44(B)).
• Underground. Direct-buried communications cable is kept at least 12 inches from power or Class 1 conductors, unless one of the conditions in the section applies, such as where the power conductors are in a raceway or have a metal cable armor (NEC 800.47(A)).
• Lightning conductors. Where practicable, at least 6 feet between communications cables on buildings and lightning conductors (NEC 800.53).

Entering the building

• Unlisted outside plant cable. The cable the utility runs outdoors is often not listed for building use. It may continue inside for not more than 50 feet from the point of entrance, if it ends in an enclosure or at a listed primary protector, under the conditions in the section, which also limit the building spaces it may pass through (NEC 800.48). Past that, a listed cable type, or another arrangement the section allows, is required.
• Primary protector. Where a circuit is exposed to accidental contact with power conductors or to lightning, a listed primary protector is installed at the entrance, as the section describes (NEC 800.50(A)).
• Bonding. The primary protector and the metallic members of the cable, such as a coaxial cable’s outer shield, are bonded to the building’s grounding electrode system, normally at the intersystem bonding termination near the service. Check the bonding conductor’s material, minimum size and length limit in your 2026 NEC, following the cross-references from Article 800. The intersystem bonding termination itself is an Article 250 rule; see NEC 250 grounding and bonding mistakes.

CATV coaxial cable carrying power

Coaxial cable in a CATV system may carry power to equipment that is directly part of the radio frequency distribution system, if the voltage is not over 60 volts and the source is power-limited. Power is blocked from premises devices that are not meant to be powered through the coaxial cable (NEC 820.15).

Worked example: entrance cable length

An unlisted outside plant communications cable enters a building through an exterior wall and runs 65 feet through an ordinary interior space to a listed primary protector.

1. Rule. Unlisted outside plant cable may run not more than 50 feet inside from the point of entrance, ending in an enclosure or at a listed primary protector (NEC 800.48).
2. Compare. 65 feet is more than 50 feet.
3. Result. Not compliant as installed. Relocate the listed primary protector as close as practicable to the point of entrance, keeping the unlisted cable within the 50-foot limit, and check the protector location requirements and the building-space limits in your 2026 NEC. Or use a listed cable type the section allows for the longer run.

Check yourself

1. On a shared pole, which goes higher: communications cables or power conductors? Power conductors. Where practicable, communications cables run below them, with the clearances the section sets.
2. How far apart are direct-buried communications cable and power conductors in the basic rule? At least 12 inches, unless a condition in the section applies.
3. What voltage limit applies to power carried on CATV coaxial cable? Not over 60 volts, from a power-limited source.

FAQ

Sources checked October 2026

• PSI Candidate Information Bulletin, Texas electrician examinations (updated September 15, 2026): https://test-takers.psiexams.com/api/content/bulletin/1682
• NFPA 70, National Electrical Code, 2026 Edition, Section 90.3 and Articles 250, 800, 810, 820 and 830