circuit service drops. The clearance
requirement shall apply at all points along the drop, and
it shall increase to 1.02 m (40 in.) at the pole.
(C) On Masts. Aerial coaxial cables shall be permitted to be attached to an above-the-roof raceway mast that does not enclose or support conductors of electric light or power circuits.
(D) Above Roofs. Coaxial cables shall have a vertical clearance of not less than 2.5 m (8 ft) from all points of roofs above which they pass.
Exception No. 1: Auxiliary buildings such as garages and the like.
Exception No. 2: A reduction in clearance above only the overhanging portion of the roof to not less than 450 mm (18 in.) shall be permitted if (1) not more than 1.2 m (4 ft) of communications service drop conductors pass above the roof overhang, and (2) they are terminated at a raceway mast or other approved support.
Exception No. 3: Where the roof has a slope of not less than 100 mm in 300 mm (4 in. in 12 in.), a reduction in clearance to not less than 900 mm (3 ft) shall be permitted.
(E) Between Buildings. Coaxial cables extending between buildings and also the supports or attachment fixtures shall be acceptable for the purpose and shall have sufficient strength to withstand the loads to which they may be subjected.
Exception: Where a coaxial cable does not have sufficient strength to be self-supporting, it shall be attached to a supporting messenger cable that, together with the attachment fixtures or supports, shall be acceptable for the purpose and shall have sufficient strength to withstand the loads to which they may be subjected.
(F) On Buildings. Where attached to buildings, coaxial cables shall be securely fastened in such a manner that they will be separated from other conductors in accordance with 820.44(F)(1), (F)(2), and (F)(3).
(1) Electric Light or Power. The coaxial cable shall have a separation of at least 100 mm (4 in.) from electric light, power, Class 1, or non-power-limited fire alarm circuit conductors not in raceway or cable, or shall be permanently separated from conductors of the other system by a continuous and firmly fixed nonconductor in addition to the insulation on the wires.
(2) Other Communications Systems. Coaxial cable shall be installed so that there will be no unnecessary interference in the maintenance of the separate systems. In no case shall the conductors, cables, messenger strand, or equipment of one system cause abrasion to the conductors, cable, messenger strand, or equipment of any other system.
(3) Lightning Conductors. Where practicable, a separa- tion of at least 1.8 m (6 ft) shall be maintained between any coaxial cable and lightning conductors.
FPN: For additional information regarding overhead wires and cables, see ANSI C2-2007, National Electric Safety Code, Part 2, Safety Rules for Overhead Lines.
820.47 Underground Circuits Entering Buildings. Un derground coaxial cables entering buildings shall comply with 820.47(A) and (B).
(A) Underground Systems with Electric Light and Power Conductors. Underground coaxial cables in a duct, pedestal, handhole enclosure, or manhole that contains electric light