Click to see a Glossary of Lightning Terms

Lightning is the second leading cause of storm related deaths in the US second only to floods. According to the National Fire Protection Association "During 2004-2008, U.S. local fire departments responded to an estimated average of 24,600 fires per year that were started by lightning. These fires caused an average of 12 civilian deaths, 47 civilian injuries, and $407 million in direct property damage per year. "


Lightning Do's, Don'ts and FAQ

Lightning Kills. Be Safe

Indoor Don'ts

  • If it doesn't run on batteries. Don't run it.
  • Don't use radios, T.V., or any other electric appliance.
  • But, don't unplug an appliance during a storm either.
  • Don't go near electric outlets and switches.
  • Don't use the telephone. Lightning loves wires.
  • Don't use the sink, bath tub, washing machine or dryer.
  • Don't go near large metallic objects (steel I beams, garage door tracks, etc.)
  • Don't go near stoves, funaces, or radiators.
  • Don't go near windows and fireplaces.
  • Don't put yourself between any of the above.

Indoor Do's

  • Do sit on the floor in the center of a large room, or interior closet, away from all of the items previously listed.
  • Do get a U.L Approved Koshofer Lightning Protection system for your home or business.
  • Sit back, and enjoy nature's most magnificent spectacle.

Important. if your hair stands on end, you are about to be struck by lighting. Drop to crouched position (catcher's position) quickly. Rest your elbows on your knees. Get on the balls of your feet, and keep your head down. This position gives you the lowest profile with the least contact to the ground.

Outdoor Do's
(in order of preference)

  • Do get inside a house with U.L Approved lightning protection.
  • Do get inside an unprotected building and observe indoor precautions.
  • Do get inside a large steel structured building.
  • Do get inside a car with an all-steel top.
  • Do get inside a cave, hole, culvert, or deep depression.
  • If caught in wooded area, seek thick growth of small or medium trees.

Outdoor Don'ts

  • Don't go near playground equipment.
  • Don't go near isolated trees or poles.
  • Don't go near hilltops.
  • Don't go near wire fences, above ground pipes or railings.
  • Don't swim. Get out of the water.
  • Don't fish.
  • Don't go boating. Head for shore immediately.
  • Don't go near open fields. Better to lose a game than a life.

Lightning has never damaged a Koshofer Lightning Protected Structure.


Glossary of Lightning Terms

Lightning Protection System. This term refers to systems as described and detailed in this standard. A lightning protection system is a complete system of air terminals, conductors, ground terminals, interconnecting conductors, surge suppression devices, and other connectors or fittings required to complete the system.


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Air Terminal. An air terminal is that component of a lightning protection system that is intended to intercept lightning flashes. [See Picture]

Approved.* Acceptable to the authority having jurisdiction.

Authority Having Jurisdiction.* The organization, office, or individual responsible for approving equipment, an installation, or a procedure.

Bonding. An electrical connection between an electrically conductive object and a component of a lightning protection system that is intended to significantly reduce potential differences created by lightning currents. [See Picture]

Cable. A conductor formed of a number of wires stranded together. [See Picture]

Chimney. A smoke or vent stack having a flue with a cross-sectional area less than 500 in.' (0.3 in') and a total height less than 75 ft (23 in).  [See Picture]

Class I Materials. Lightning conductors, air terminals, ground terminals, and associated fittings required by this standard for the protection of structures not exceeding 75 ft (23 in) in height. [See Picture]

Class II Materials. Lightning conductors, air terminals, ground terminals, and associated fittings required by this standard for the protection of structures exceeding 75 ft (23 in) in height. [See Picture]

Combustible Liquid. A liquid having a flash point at or above 100F (37.8C).

Combustible liquids shall be subdivided as follows:

  • Class II liquids shall include those having flash points at or above 100F (37.8C) and below 140F (60C).

  • Class IIIA liquids shall include those having flash points at or above 140F (60C) and below 200F (93C).

  • Class IIIB liquids shall include those having flash points at or above 200F (93C).

Conductor, Bonding. A conductor intended to be used for potential equalization between grounded metal bodies and the lightning protection system.

Conductor, Main. A conductor intended to be used to carry lightning currents between air terminations and ground terminals.

Copper-clad Steel. Steel with a coating of copper bonded to it.

Explosive Materials. These include explosives, blasting agents, and detonators as authorized for transportation by the Department of Transportation or the Department of Defense.

Fastener. An attachment to secure the conductor to the structure.

Flame Protection. Self-closing gauge hatches, vapor seals, pressure-vacuum breather valves, flame arresters, or other reasonably effective means to minimize the possibility of flame entering the vapor space of a tank.

Flammable Air-Vapor Mixtures. When flammable vapors are mixed with air in certain proportions, the mixture will burn rapidly when ignited. The combustion range for ordinary petroleum products, such as gasoline, is from about 11/2 to 71/2 percent of vapor by volume, the remainder being air.

Flammable Liquid. A liquid having a flash point below 100F (37.8C) and having a vapor pressure not exceeding 40 psia (275 kPa) at 100'F (37.8C) shall be known as a Class I liquid.

Class I liquids shall be subdivided as follows:

  • Class IA shall include those having flash points below 73F (22.8C) and having a boiling point below 100F (37.8C).

  • Class III shall include those having flash points below 73F (22.8C) and having a boiling point at or above 100F (37.8C).

  • Class IC shall include those having flash points at or above 73F (22.8C) and below 100F (37.8C).

Flammable Vapors. The vapors given off from a flammable or combustible liquid at or above its flash point.

Flash Point. The minimum temperature at which a liquid gives off vapor in sufficient concentration to form an ignitable mixture with air near the surface of the liquid within the vessel, as specified by appropriate test procedure and apparatus.

Gastight. Structures so constructed that gas or air can neither enter nor leave the structure except through vents or piping provided for the purpose.

Ground Terminal. The portion of a lightning protection system such as a ground rod, ground plate, or ground conductor that is installed for the purpose of providing electrical contact with the earth. [See Picture]

Grounded. Connected to earth or to some conducting body that is connected to earth.

High-Rise Building. For the purposes of this standard a high-rise building is a structure exceeding 75 ft (23 in) in height.

Labeled. Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation that maintains periodic inspection of production of labeled equipment or materials and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner.

Listed.* Equipment or materials included in a list published by an organization acceptable to the authority having jurisdiction and concerned with product evaluation that maintains periodic inspection of production of listed equipment or materials and whose listing states either that the equipment or material meets appropriate standards or has been tested and found suitable for use in a specified manner.

Loop Conductor. A conductor encircling a structure that is used to interconnect ground terminals, main conductors, or other grounded bodies.

Metal-clad Structure. A structure with sides or roof, or both, covered with metal.

Metal-framed Structure. A structure with electrically continuous structural members of sufficient size to provide an electrical path equivalent to that of the lightning conductors covered in this standard.

Shall. Indicates a mandatory requirement.

Should. Indicates a recommendation or that which is advised but not required.

Sideflash. An electrical spark, caused by differences of potential, occurring between conductive metal bodies or between such metal bodies and a component of the lightning protection system or ground. [See Picture]

Spark Gap. As used in this standard, the term spark gap means any short air space between two conductors electrically insulated from or remotely electrically connected to each other.

Stack, Heavy-duty. A smoke or vent stack is classified as heavy-duty if the cross-sectional area of the flue is greater than 500 in.2 (0.3 m2) or the height is greater than 75 ft (23 m). [See Picture]

Striking Distance. The distance over which the final breakdown of the initial stroke occurs.

Surge Arrester. A protective device for limiting surge voltages by discharging or bypassing surge current. It also prevents continued flow of follow current while remaining capable of repeating these functions.

Vapor Openings. Openings through a tank shell or roof above the surface of the stored liquid. Such openings might be provided for tank breathing, tank gauging, fire fighting, or other operating purposes.

Watercraft. For the purpose of this document, watercraft is defined as all forms of boats and vessels up to 300 gross tons (272 metric tons) used for pleasure or commercial purposes, but excluding seaplanes, hovercraft, vessels with a cargo of flammable liquids, and submersible vessels.

Zone of Protection. The zone of protection is that space adjacent to a lightning protection system that is substantially immune to direct lightning flashes. [See Picture]

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Koshofer Lightning Protection Co., Inc.
Old Church Road
Putnam Valley, NY 10579
(845) 528-7455
Fax: (845) 528-7465
Main Office email: wrkoshofer@prodigy.net

Mid & Upper Hudson Valley, Catskills and NE PA: phil@koshoferlightning.com