UL 96A-2016 pdf download

UL 96A-2016 pdf download.lnstallation Requirements for Lightning Protection Systems.
9.3 Down conductors
9.3.1 Down conductors shall be as widely separated as practical and located at the perimeter. outer most walls, of a structure. Their location depends on such factors as: the placement of air terminals; the most direct coursing of conductors; earth condihons; security against displacement; the location of large metallic bodies: and the location of underground metallic piping systems.
9.3.2 At least two down conductors shall be installed regardless of the kind of structure, including steeples except as permitted in Section 16. General. Structures exceeding 250 feet (76.2 m) in perimeter shall have a down conductor for every 100 feet (30.5 m) of perimeter or fraction thereof. The total number of down Conductors shall be such that the average distance between all down conductors does not exceed 100 feet (30.5 m). (including the first 250 feet (76.2 m) of perimeter). When determining the perimeter of a structure, only the perimeter of the roof area requiring protection is to be measured. Lower roofs or projections which are located within a zone of protection are to be excluded. See Figure 9.5. When determining the perimeter of a pitched roof structure, measuring the horizontal projection (footpnnt) of the roof meets the intent of this requirement.
9.3.3 Each down conductor located in a runway. driveway, school playground, cattle yard, public walk, or other similar location shall be protected from mechanical damage or displacement. A conductor that runs through metal pipe or tubing shall be bonded to both ends of the pipe or tubing. The down conductor shall be protected for a minimum distance of 6 feet (1.8 m) above grade level.
9,3.4 A down conductor entering corrosive soil shall be protected from corrosion by a protective coating for a distance not less than 3 feet (914 mm) above grade level and for the entire length below grade level.
9.3.5 A down conductor shall not be routed within a downspout, gutter or leader. A down conductor may be supported on the exterior of these parts provided they are constructed of materials having a minimum thickness of .0179 inches (0.455 mm) (for example, 26 gauge steel or 25 gauge aluminum) and are permanently fastened to the stwcture being protected.
9.4 InterconnectIng conductors
9.4.1 A main-sized conductor and bonding connector shall be used for interconnection of metallic water systems, steam or hot water heating systems, sprinkler pipes, elecinc service, telephone systems, antenna grounds, and other large grounded metallic masses.
9.4.2 A secondary conductor shall not be smaller than 6 AWG (13.3 mm2 copper or equivalent.
10 Grounding
10.1 General
10.1.1 Each down conductor shall terminate in a grounding electrode.
10.1.2 Grounding electrode placement and configuration shall be any combination of the specifications outlined in this section.
10.1.3 Grounding electrodes shall be solid wire or strip, rod, solid plate, concrete-encased electrodes, ground ring electrode (loop conductor), or trenched electrode. The use of stranded cable as a grounding electrode shall be limIted to a concrete-encased electrode, ground ring electrode (loop conductor), or trenched electrode.
10.1.4 Each ground rod shall be not less than 1/2 inch (12.7 mm) in diameter and not less than 8 feet (2.4 m) long and shall be made of copper-clad steel, solid copper, stainless steel, or stainless steel clad.
10.1.5 Ground rod connections shall be made by main size clamp type connectors, by welding, or by brazing. Clamps shall make contact with the ground rod and conductor for a distance of not less than 1-1/2 inches (38 mm) measured parallel to the axis of the ground rod. Clamps shalt be secured with at least two bolts or machine screws. Welded connections shall have a weld area at least two times the cross-sectional area of the conductor.
10.1.6 Grounding electrodes shall be located at least 2 feet (610 mm) from the foundation wall. Ground rods shall extend vertically not less than 10 feet (3 m) into the earth. The earth shall be compacted and made tight against the full length of the conductor or grounding electrode. See Figure 10.1.