Provide a complete lightning protection system as shown on the drawings and as specified herein. The system shall be installed by a firm actively engaged in the installation of Master Labeled Lightning Protection Systems and shall be so listed by Underwriters Laboratories Inc. The completed system shall comply with the latest editions of the Installation Requirements for Lightning Protection Systems, UL96A.
All materials used in the installation shall be labeled or listed by Underwriters Laboratories Inc. for use in Master Labeled lightning protection systems. The catalog numbers referred to on the drawings are those of APPROVED LIGHTNING PROTECTION CO, INC. 65 Mahan Street, West Babylon NY, 11704; 631 643-6327 - fax 643-1125; www.approvedlightning.com
Generally all materials shall be of copper and/or copper-bronze. In locations where system components are mounted on aluminum surfaces, aluminum materials shall be used to avoid electrolytic corrosion of the dissimilar metals. See Tank and Stack specifications for materials to be used in these areas.
Materials shall be sized in accordance with the material requirements of UL96A. Class I materials shall be used for systems on structures not exceeding 75 feet in height and Class II materials shall be used for systems on structures 75 feet or more above grade.
Secondary surge protection shall be provided on all incoming services in accordance with current UL requirements.
Air terminals shall project a minimum of ten inches above the area protected and shall be located at intervals not exceeding 20'-0 along ridges and around the perimeter of flat or gently sloping roofs. Flat or gently sloping roofs exceeding 50'-0'' in width shall be protected with additional air terminals located at intervals not exceeding 50'-0'' in the flat or gently sloping area. Air terminals shall be located within 18" of roof edges and outside corners of protected areas.
Air terminals shall be installed for stacks, flues, mechanical equipment, and other objects not located within a zone of protection. Non-metallic objects or metal objects having a metal thickness of less than 3/16'' require the installation of air terminals and required conductors. Objects having a metal thickness 3/16'' or greater shall be connected to the lightning protection system per code requirements using main size conductor and connector fittings having 3 square inches of surface contact area.
Air terminal mounting bases shall be of cast construction and securely fastened to the structure in accordance with code requirements.
Main conductors shall be sized in accordance with the Class I or Class II material requirements above and shall provide a two-way path from each air terminal horizontally or downward to connections with ground terminals. Conductors shall be free of excessive splices and sharp bends. No bend of a conductor shall form an included angle of less than 90 degrees nor have a radius of bend of less than 8 inches. Conductors shall be secured to the structure at intervals not exceeding 3'-0''.
Down conductors shall be of copper, should be concealed in the exterior wall construction and may be run in conduit. If metallic conduit is used it must be compatible with the conductor material and the down conductor must be bonded to the conduit at each entry and exit point. Down conductors shall be spaced at intervals averaging not more than 100 feet around the perimeter of the structure. In no case shall a structure have fewer than two down conductors. Concrete structures 200' or more in height additionally require a counterpoise loop interconnecting the ground rods in the earth as well as additional interconnecting counterpoises every 200' up the structure.
In the case of structural steel frame construction, down conductors may be omitted and roof conductors shall be connected to the structural steel frame at intervals averaging 60 feet on center around the perimeter of the structure. Connections to the steel frame shall be made top and bottom with bonding plates having 8 square inches of contact or by exothermic weld connections. Cables connected to the steel columns at the bottom shall terminate to ground electrodes as described herein.
Roof penetrations required for down conductors or for connections to structural steel framework shall be made using appropriate roof flashing. Roof flashing and any adhesives required shall be compatible with the roofing system shall be furnished and installed by the roofing contractor.
Common grounding of all ground mediums entering the building shall be ensured by interconnecting the lightning protection system to the cold water ground using main size conductors and fittings.
Grounded metal bodies located within six feet of the lightning protection system shall be bonded to the system using bonding connections and fittings.
Ground electrodes shall be provided for each down conductor and shall consist of 3/4''x 10'-0'' minimum copper-clad ground rod. The down conductor shall be connected to the ground rod using a bronze ground rod clamp having at least 1-1/2'' of contact between the rod and the conductor, measured parallel to the axis of the rod, or by a Cadweld connection. Ground rod connections shall be located 2 feet 6 inches below grade, preferably 2 feet from the foundation wall and shall extend a minimum of 12' 6" into the earth. In rocky areas ground plates with an equivalent soil contact area may be used in combination with Cadweld Ground Enhancement Material.
Where the structural steel framework is utilized as main conductors for the system, perimeter columns shall be grounded at intervals averaging not more than 60 feet apart. Columns shall be grounded using bonding plates having 8 square inches of surface contact area or by Cadweld connections. Conductors from the ground connections to the ground termination shall be Class II copper lightning conductors.
Upon completion of the installation the contractor shall deliver to the owner the Master Label issued by Underwriters Laboratories Inc. for this system. If the protected structure is an addition to or is attached to an existing structure that does not have a lightning protection system, the contractor shall certify that the system installed complies with UL requirements and advise the owner of the lightning protection work required on the existing structure to obtain the Master Label. If the existing structure does have a lightning protection system, the contractor shall advise the owner of any additional work required on the existing system to bring it into compliance with current UL requirements and thus qualify for the Reconditioned Master Label of Underwriters Laboratories Inc.