2.1.6
Lightning Protection Components
Lightning protection components, such as bonding plates, air terminal
supports, chimney bands, clips, and fasteners shall conform to UL 96,
classes as applicable.
PART 3
EXECUTION
3.1
INTEGRAL SYSTEM
3.1.1
General Requirements
The lightning protection system shall consist of air terminals, roof
conductors, down conductors, ground connections, and grounds, electrically
interconnected to form the shortest distance to ground. All conductors on
the structures shall be exposed except where conductors are in protective
sleeves exposed on the outside walls. Secondary conductors shall
interconnect with grounded metallic parts within the building.
Interconnections made within side-flash distances shall be at or above the
level of the grounded metallic parts.
3.1.1.1
Air Terminals
Air terminal design and support shall be in accordance with NFPA 780.
Terminals shall be rigidly connected to, and made electrically continuous
with, roof conductors by means of pressure connectors or crimped joints of
T-shaped malleable metal and connected to the air terminal by a dowel or
threaded fitting. Air terminals at the ends of the structure shall be set
not more than 600 mm 2 feet from the ends of the ridge or edges and corners
of roofs. Spacing of air terminals 600 mm 2 feet in height on ridges,
parapets, and around the perimeter of buildings with flat roofs shall not
exceed 7.5 meters 25 feet. In specific instances where it is necessary to
exceed this spacing, the specified height of air terminals shall be
increased not less than 50 mm 2 inches for each 300 mm foot of increase
over 7.5 meters 25 feet. On large, flat or gently sloping roofs, as
defined in NFPA 780, air terminals shall be placed at points of the
intersection of imaginary lines dividing the surface into rectangles having
sides not exceeding 15 m 50 feet in length. Air terminals shall be secured
against overturning either by attachment to the object to be protected or
by means of a substantial tripod or other braces permanently and rigidly
attached to the building or structure. Metal projections and metal parts
of buildings, smokestacks, and other metal objects that do not contain
hazardous materials and that may be struck but not appreciably damaged by
lightning, need not be provided with air terminals. However, these metal
objects shall be bonded to the lightning conductor through a metal
conductor of the same unit weight per length as the main conductor. [Where
metal ventilators are installed, air terminals shall be mounted thereon,
where practicable. Any air terminal erected by necessity adjacent to a
metal ventilator shall be bonded to the ventilator near the top and
bottom.] Where metal ventilators are installed with air terminals mounted
thereon, the air terminal shall not be more than 610 mm 24 inches away from
the farther edge or corner. If the air terminal is farther than this
distance, an additional air terminal shall be added in order to meet this
requirement. Where metal ventilators are installed with air terminals
mounted adjacent, the air terminal shall not be more than 610 mm 24 inches
away from the farther edge or corner. If the air terminal is farther than
this distance, an additional air terminal shall be added in order to meet
this requirement.
SECTION 13100A
Page 8
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