Lightning & NEC Requirements

[stgeorge]

Hello to all,

My question is concerning Lightning Rods and building requirements according to the NEC. I have used its Index/Contents and come up short of the answer i`m looking for. Many of the buildings I work in do not have lightning rods but a few do. some buildings are mobile trailers and all buildings are one story.
So .... where do i find my answer as to why these buildings do not have protection from possible lightning strikes and if they should have this protection.
Thank you in advance.
JIM

 

[muskiedog]

Nfpa 780

Nfpa 780

Lightning Protection requirements.

 

[celtic]

Online Access to NFPA 780: Standard for the Installation of Lightning Protection Systems, 2008 Edition

[SIZE=-1]Document Scope:
1.1 Scope.
1.1.1 This document shall cover traditional lightning protection system installation requirements for the following:
(1) Ordinary structures
(2) Miscellaneous structures and special occupancies
(3) Heavy-duty stacks
(4) Watercraft
(5) Structures containing flammable vapors, flammable gases, or liquids that give off flammable vapors

1.1.2* This document shall not cover lightning protection system installation requirements for the following:
(1) Explosives manufacturing buildings and magazines
(2) Electric generating, transmission, and distribution systems

1.1.3 This document shall not cover lightning protection system installation requirements for early streamer emission systems or charge dissipation systems.

A.1.1.2 Electric generating facilities whose primary purpose is to generate electric power are excluded from this standard with regard to generation, transmission, and distribution of power. Most electrical utilities have standards covering the protection of their facilities and equipment. Installations not directly related to those areas and structures housing such installations can be protected against lightning by the provisions of this standard. Lightning protection systems for structures used for production or storage of explosive materials require special consideration because the contents of such structures are sensitive to arc or spark ignition.

Annex K provides guidance for protection of structures housing explosive materials.

Other standards and handbooks that provide guidance for military applications are found in Annex O.[/SIZE]

 

[bphgravity]

Almost no building or structure REQUIRES lightning protection. Even here in Florida (highest lightning densities in the US), only 3 occupancy types require an LPS in compliance with the 780. For the most part, it is a design consideration based on a risk assessment.

 

[JohnJ0906]

Almost no building or structure REQUIRES lightning protection. Even here in Florida (highest lightning densities in the US), only 3 occupancy types require an LPS in compliance with the 780. For the most part, it is a design consideration based on a risk assessment.

Out of curiosity, which 3 occupancy types?

 

[bphgravity]

Hospitals, Nursing Homes, and Educational facilities.

 

[JohnJ0906]

Thank you Bryan :smile: