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Quizzes on the Code

Dec 1, 2002 12:00 PM, By Mike Holt, NEC Consultant

Choose the best answer:

Communications cables will be considered abandoned if they're neither terminated at both ends with a connector or other equipment nor identified for future use with a tag.
(a) true
(b) false
Exposed communications cables must be secured to structural components by straps, staples, hangers, or similar fittings designed and installed so as to not damage the cable.
(a) true
(b) false
When it isn't practicable to install a primary protector grounding conductor of less than 20 ft in length in one- and two-family dwellings, a separate ___ ft communications ground rod must be driven and bonded to the power grounding electrode system with a 6 AWG conductor.
(a) 5
(b) 8
(c) 10
(d) 20
Communications cables installed in buildings must be listed as suitable for the purpose unless their length within the building doesn't exceed ___ ft.
(a) 5
(b) 25
(c) 50
(d) 100
You must install underground coaxial cables at least 12 in. from light or power conductors, even if they're installed in a raceway or nonmetallic cable, such as UF or USE type cable.
(a) true
(b) false
The grounding conductor used to ground masts and metal structures supporting antennas as well as each conductor of a lead-in from an outdoor antenna must be run in as straight a line as practicable from the mast or discharge unit to the grounding electrode.
(a) true
(b) false
A coaxial cable's outer conductive shield must be grounded at the building premises as close to the point of cable entrance or attachment as practicable.
(a) true
(b) false
All accessible portions of abandoned network-powered broadband cable must be removed.
(a) true
(b) false

Answers and Discussion

(a), true. Because 800.52(B) requires abandoned cables to be removed, this definition was necessary to clarify which cables can stay and which must go.
(a), true. The revised text in 800.6 clarifies that communications cables must be properly secured and protected from physical damage.
(a), 5 ft. An Exception in 800.40(A)(4) provides an alternative for situations when it's not practicable to meet the maximum 20-ft length restriction. It references the requirements of 800.40(B)(2)(2), which requires connection to an effectively grounded metal structure or to a ground rod or pipe no less than 5 ft in length and .5 in. in diameter.
(c), 50 ft. In general, communications cables installed in a building must be listed, but Exception No. 3 to 800.50 permits unlisted cable to enter the building for a distance of 50 ft.
(b), false. The 12-in. separation rule doesn't apply if the light or power conductors are installed in a raceway or nonmetallic raceway, or if the coaxial cables are installed in a raceway [820.11(B)].
(a), true. Per 810.21(E), you must run the grounding conductor for the antenna mast and/or antenna discharge unit in as straight a line as practicable from the mast or discharge unit to the grounding electrode. Failure to do so can cause lightning energy to be routed into the structure, rather than to the earth.
(a), true. This change to 820.33 adds clarity and makes this section consistent with other communications articles in the 2002 NEC.
(a), true. A new rule [830.3(A)] requires the accessible portions of abandoned cables, as defined in 830.2, to be removed in order to limit the spread of fire or by-products of combustion within a building.

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