What Does Lightning Rods Do

Metal rod intended to protect the structure from a lightning strike

Diagram of a uncomplicated lightning protection organisation

A lightning rod (US, AUS, CA) or lightning conductor (UK) is a metal rod mounted on a structure and intended to protect the construction from a lightning strike. If lightning hits the structure, it volition preferentially strike the rod and be conducted to ground through a wire, instead of passing through the structure, where it could kickoff a burn or cause electrocution. Lightning rods are as well called finials, air terminals, or strike termination devices.

In a lightning protection system, a lightning rod is a single component of the system. The lightning rod requires a connexion to earth to perform its protective function. Lightning rods come up in many unlike forms, including hollow, solid, pointed, rounded, flat strips, or even bristle brush-like. The master attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Copper and its alloys are the nigh common materials used in lightning protection.^[1]

History [edit]

The principle of the lightning rod was first detailed past Prokop Diviš in Přímětice, in what is now the Czech Republic in 1753.

"Machina meteorologica" invented by Diviš worked like a lightning rod

Franklin's earliest papers on electricity^[2]

"Tesla's Dragon". Copper lightning rod at the Tesla Science Eye, based on a Hemingray insulator

As buildings become taller, lightning becomes more of a threat. Lightning can impairment structures made of most materials, such as masonry, forest, physical, and steel, because the huge currents and voltages involved can heat materials to loftier temperature. The heat causes a potential for structure burn, and its rapidity can lead to explosive damage besides.

Russia [edit]

A lightning conductor may have been intentionally used in the Leaning Tower of Nevyansk. The spire of the belfry is crowned with a metallic rod in the shape of a gilt sphere with spikes. This lightning rod is grounded through the rebar carcass, which pierces the entire building.

The Nevyansk Belfry was built between 1721 and 1745, on the orders of industrialist Akinfiy Demidov. The Nevyansk Belfry was built 28 years earlier Benjamin Franklin's experiment and scientific explanation. Nevertheless, the true intent backside the metallic rooftop and rebars remains unknown.^[3]

Europe [edit]

The church building tower of many European cities, which was usually the highest structure in the city, was likely to be hit past lightning. Early, Christian churches tried to prevent the occurrence of the damaging effects of lightning past praying. Peter Ahlwardts ("Reasonable and Theological Considerations about Thunder and Lightning", 1745) advised individuals seeking cover from lightning to become anywhere except in or around a church.^[four]

There is an ongoing debate over whether a "metereological automobile", invented by Premonstratensian priest Prokop Diviš and erected in Přímětice (now function of Znojmo), Moravia (now the Czech republic) in June 1754, does count as an individual invention of the lightning rod. Diviš's appliance was, according to his individual theories, aimed towards preventing thunderstorms altogether by constantly depriving the air of its superfluous electricity. The apparatus was, withal, mounted on a free-standing pole and probably meliorate grounded than Franklin's lightning rods at that time, so it served the purpose of a lightning rod.^[5] After local protests, Diviš had to cease his weather condition experiments effectually 1760.

United States [edit]

In what later became the United States, the pointed lightning rod usher, also chosen a lightning attractor or Franklin rod, was invented by Benjamin Franklin in 1752 as part of his groundbreaking exploration of electricity. Although not the first to propose a correlation between electricity and lightning, Franklin was the starting time to propose a workable system for testing his hypothesis.^[half-dozen] Franklin speculated that, with an fe rod sharpened to a betoken, "The electric burn down would, I think, exist drawn out of a cloud silently, earlier it could come nearly plenty to strike." Franklin speculated near lightning rods for several years before his reported kite experiment.^{[ citation needed ]}

In the 19th century, the lightning rod became a decorative motif. Lightning rods were embellished with ornamental glass balls^[7] (now prized by collectors). The ornamental appeal of these drinking glass balls has been used in atmospheric condition vanes. The main purpose of these balls, however, is to provide evidence of a lightning strike by shattering or falling off. If after a storm a ball is discovered missing or broken, the holding possessor should and so check the building, rod, and grounding wire for impairment.

Balls of solid glass occasionally were used in a method purported to prevent lightning strikes to ships and other objects.^{[ commendation needed ]} The idea was that glass objects, being non-conductors, are seldom struck by lightning. Therefore, goes the theory, there must be something well-nigh glass that repels lightning. Hence the best method for preventing a lightning strike to a wooden ship was to bury a small solid glass ball in the tip of the highest mast. The random beliefs of lightning combined with observers' confirmation bias ensured that the method gained a good bit of credence even after the development of the marine lightning rod before long after Franklin's initial piece of work.

The showtime lightning conductors on ships were supposed to exist hoisted when lightning was anticipated, and had a low success rate. In 1820 William Snow Harris invented a successful system for fitting lightning protection to the wooden sailing ships of the day, but despite successful trials which began in 1830, the British Purple Navy did not prefer the system until 1842, past which time the Imperial Russian Navy had already adopted the organisation.

In the 1990s, the 'lightning points' were replaced as originally synthetic when the Statue of Freedom atop the United states Capitol building in Washington, D.C. was restored.^[viii] The statue was designed with multiple devices that are tipped with platinum. The Washington Monument also was equipped with multiple lightning points,^[9] and the Statue of Liberty in New York Harbor gets striking by lightning, which is shunted to ground.

Lightning protection organization [edit]

A lightning protection system is designed to protect a structure from damage due to lightning strikes by intercepting such strikes and safely passing their extremely high currents to ground. A lightning protection system includes a network of air terminals, bonding conductors, and ground electrodes designed to provide a low impedance path to footing for potential strikes.

Lightning protection systems are used to prevent lightning strike damage to structures. Lightning protection systems mitigate the burn down hazard which lightning strikes pose to structures. A lightning protection system provides a depression-impedance path for the lightning electric current to lessen the heating effect of current flowing through flammable structural materials. If lightning travels through porous and water-saturated materials, these materials may literally explode if their h2o content is flashed to steam by estrus produced from the high electric current. This is why trees are often shattered by lightning strikes.

Because of the high energy and electric current levels associated with lightning (currents tin can exist in excess of 150,000 A), and the very rapid rise time of a lightning strike, no protection organization can guarantee absolute rubber from lightning. Lightning current will divide to follow every conductive path to ground, and even the divided electric current tin can cause impairment. Secondary "side-flashes" tin be plenty to ignite a burn, blow apart brick, stone, or physical, or injure occupants within a construction or edifice. Yet, the benefits of bones lightning protection systems have been evident for well over a century.^[10]

Laboratory-calibration measurements of the effects of [any lightning investigation research] do non calibration to applications involving natural lightning.^[11] Field applications take mainly been derived from trial and mistake based on the best intended laboratory research of a highly complex and variable phenomenon.

The parts of a lightning protection organisation are air terminals (lightning rods or strike termination devices), bonding conductors, basis terminals (ground or "earthing" rods, plates, or mesh), and all of the connectors and supports to complete the system. The air terminals are typically arranged at or forth the upper points of a roof structure, and are electrically bonded together past bonding conductors (called "downward conductors" or "downleads"), which are continued by the most direct road to ane or more grounding or earthing terminals.^[12] Connections to the earth electrodes must not only take low resistance, merely must take low self-inductance.

An example of a structure vulnerable to lightning is a wooden barn. When lightning strikes the barn, the wooden structure and its contents may be ignited by the oestrus generated by lightning current conducted through parts of the structure. A basic lightning protection system would provide a conductive path between an air terminal and globe, so that well-nigh of the lightning's current will follow the path of the lightning protection system, with substantially less current traveling through flammable materials.

Originally, scientists believed that such a lightning protection system of air terminals and "downleads" directed the electric current of the lightning down into the world to be "prodigal". Nonetheless, loftier speed photography has clearly demonstrated that lightning is actually composed of both a deject component and an oppositely charged footing component. During "cloud-to-ground" lightning, these oppositely charged components usually "meet" somewhere in the atmosphere well in a higher place the earth to equalize previously unbalanced charges. The heat generated equally this electrical current flows through flammable materials is the gamble which lightning protection systems endeavour to mitigate by providing a low-resistance path for the lightning excursion. No lightning protection organisation can be relied upon to "comprise" or "control" lightning completely (nor thus far, to forbid lightning strikes entirely), simply they do seem to help immensely on about occasions of lightning strikes.

Steel framed structures can bond the structural members to earth to provide lightning protection. A metal flagpole with its foundation in the earth is its own extremely elementary lightning protection system. However, the flag(due south) flying from the pole during a lightning strike may be completely incinerated.

The majority of lightning protection systems in utilise today are of the traditional Franklin blueprint.^[12] The key principle used in Franklin-type lightning protections systems is to provide a sufficiently low impedance path for the lightning to travel through to reach ground without dissentious the edifice.^[13] This is accomplished past surrounding the building in a kind of Faraday cage. A system of lightning protection conductors and lightning rods are installed on the roof of the building to intercept whatever lightning before information technology strikes the edifice.

Construction protectors [edit]

Lightning rod on a statue.

Lightning arrester [edit]

A lightning arrester is a device used on electric power systems and telecommunication systems to protect the insulation and conductors of the system from the dissentious effects of lightning. The typical lightning arrester has a high-voltage terminal and a ground terminal.

In telegraphy and telephony, a lightning arrester is a device placed where wires enter a structure, in social club to forbid damage to electronic instruments within and ensuring the rubber of individuals near the structures. Smaller versions of lightning arresters, likewise called surge protectors, are devices that are connected between each electrical usher in a power or communications system, and the basis. They help preclude the period of the normal power or bespeak currents to footing, merely provide a path over which high-voltage lightning current flows, bypassing the connected equipment. Arresters are used to limit the ascension in voltage when a communications or power line is struck by lightning or is near to a lightning strike.

Protection of electrical distribution systems [edit]

In overhead electric transmission systems, one or two lighter ground wires may be mounted to the top of the pylons, poles, or towers not specifically used to send electricity through the filigree. These conductors, oft referred to "static", "airplane pilot" or "shield" wires are designed to be the bespeak of lightning termination instead of the high-voltage lines themselves. These conductors are intended to protect the main power conductors from lightning strikes.

These conductors are bonded to earth either through the metal structure of a pole or tower, or by additional footing electrodes installed at regular intervals forth the line. As a full general rule, overhead power lines with voltages below 50 kV do not have a "static" conductor, but nearly lines carrying more than 50 kV do. The footing conductor cablevision may also support fibre optic cables for data transmission.

Older lines may utilize surge arresters which insulate conducting lines from direct bonding with earth and may exist used equally low voltage communication lines. If the voltage exceeds a certain threshold, such as during a lightning termination to the conductor, information technology "jumps" the insulators and passes to earth.

Protection of electrical substations is as varied as lightning rods themselves, and is oftentimes proprietary to the electrical company.

Lightning protection of mast radiators [edit]

Radio mast radiators may be insulated from the ground by a spark gap at the base. When lightning hits the mast, information technology jumps this gap. A modest inductivity in the feed line between the mast and the tuning unit (usually one winding) limits the voltage increase, protecting the transmitter from dangerously high voltages. The transmitter must be equipped with a device to monitor the antenna's electrical backdrop. This is very important, every bit a accuse could remain after a lightning strike, damaging the gap or the insulators.

The monitoring device switches off the transmitter when the antenna shows incorrect behavior, e.g. as a result of undesired electrical charge. When the transmitter is switched off, these charges dissipate. The monitoring device makes several attempts to switch back on. If after several attempts the antenna continues to show improper behavior, possibly as issue of structural damage, the transmitter remains switched off.

Lightning conductors and grounding precautions [edit]

Ideally, the hush-hush office of the assembly should reside in an surface area of high ground conductivity. If the hugger-mugger cable is able to resist corrosion well, it can be covered in salt to improve its electric connectedness with the ground. While the electric resistance of the lightning usher between the air terminal and the Earth is of significant business, the inductive reactance of the usher could be more important. For this reason, the downwards usher route is kept brusque, and whatsoever curves accept a big radius. If these measures are not taken, lightning current may arc over a resistive or reactive obstruction that it encounters in the conductor. At the very least, the arc electric current will damage the lightning usher and can easily observe another conductive path, such as building wiring or plumbing, and crusade fires or other disasters. Grounding systems without low resistivity to the ground can still be effective in protecting a structure from lightning damage. When ground soil has poor electrical conductivity, is very shallow, or non-existent, a grounding system can be augmented by adding basis rods, counterpoise (footing ring) usher, cablevision radials projecting away from the building, or a physical building'south reinforcing confined tin can be used for a ground conductor (Ufer ground). These additions, while however not reducing the resistance of the system in some instances, will allow the [dispersion] of the lightning into the world without damage to the construction.^[xv]

Additional precautions must be taken to preclude side-flashes between conductive objects on or in the structure and the lightning protection system. The surge of lightning current through a lightning protection conductor will create a voltage departure between information technology and any conductive objects that are virtually information technology. This voltage difference tin can be large enough to crusade a dangerous side-flash (spark) between the 2 that can cause significant harm, especially on structures housing combustible or explosive materials. The most effective style to forbid this potential damage is to ensure the electrical continuity between the lightning protection arrangement and any objects susceptible to a side-flash. Constructive bonding will allow the voltage potential of the ii objects to rising and autumn simultaneously, thereby eliminating any risk of a side-flash.^[sixteen]

Lightning protection system design [edit]

Considerable material is used to make upward lightning protection systems, so it is prudent to consider carefully where an air terminal will provide the greatest protection. Historical understanding of lightning, from statements made by Ben Franklin, assumed that each lightning rod protected a cone of 45 degrees.^[17] This has been found to exist unsatisfactory for protecting taller structures, as it is possible for lightning to strike the side of a building.

A modeling organization based on a meliorate understanding of the termination targeting of lightning, called the Rolling Sphere Method, was developed by Dr Tibor Horváth. It has go the standard by which traditional Franklin Rod systems are installed. To sympathise this requires knowledge of how lightning 'moves'. As the pace leader of a lightning bolt jumps toward the basis, it steps toward the grounded objects nearest its path. The maximum distance that each step may travel is called the critical distance and is proportional to the electrical current. Objects are likely to be struck if they are nearer to the leader than this disquisitional distance. It is standard practice to approximate the sphere's radius every bit 46 thousand most the footing.^[18]

An object outside the critical distance is unlikely to be struck by the leader if there is a solidly grounded object within the critical altitude. Locations that are considered safety from lightning can exist determined by imagining a leader'southward potential paths equally a sphere that travels from the deject to the ground. For lightning protection, it suffices to consider all possible spheres as they touch potential strike points. To make up one's mind strike points, consider a sphere rolling over the terrain. At each point, a potential leader position is simulated. Lightning is well-nigh probable to strike where the sphere touches the ground. Points that the sphere cannot roll across and touch are safest from lightning. Lightning protectors should be placed where they will prevent the sphere from touching a structure. A weak indicate in most lightning diversion systems is in transporting the captured discharge from the lightning rod to the ground, though.^[19] Lightning rods are typically installed around the perimeter of flat roofs, or along the peaks of sloped roofs at intervals of six.1 1000 or 7.six m, depending on the elevation of the rod.^[20] When a flat roof has dimensions greater than 15 k by 15 m, additional air terminals will be installed in the center of the roof at intervals of 15 1000 or less in a rectangular grid design.^[21]

Rounded versus pointed ends [edit]

Pointed lightning rod on a edifice

The optimal shape for the tip of a lightning rod has been controversial since the 18th century. During the menstruum of political confrontation between Britain and its American colonies, British scientists maintained that a lightning rod should have a brawl on its terminate, while American scientists maintained that in that location should be a point. Every bit of 2003^[update], the controversy had non been completely resolved.^[22] It is difficult to resolve the controversy because proper controlled experiments are near impossible, but piece of work performed past Charles B. Moore, et al.,^[23] in 2000 has shed some light on the issue, finding that moderately rounded or blunt-tipped lightning rods act as marginally better strike receptors. As a result, round-tipped rods are installed on nigh new systems in the United states of america, though virtually existing systems still accept pointed rods. Co-ordinate to the written report,

[c]alculations of the relative strengths of the electric fields higher up similarly exposed abrupt and blunt rods prove that while the fields are much stronger at the tip of a sharp rod prior to whatever emissions, they decrease more speedily with distance. As a result, at a few centimeters above the tip of a 20-mm-diameter blunt rod, the strength of the field is greater than over an otherwise like, sharper rod of the same elevation. Since the field strength at the tip of a sharpened rod tends to be express by the easy formation of ions in the surrounding air, the field strengths over edgeless rods can be much stronger than those at distances greater than 1 cm over sharper ones.
The results of this written report suggest that moderately blunt metal rods (with tip height to tip radius of curvature ratios of nigh 680:1) are better lightning strike receptors than sharper rods or very edgeless ones.

In addition, the height of the lightning protector relative to the construction to exist protected and the World itself will have an issue.^{[24] [25]}

Charge transfer theory [edit]

The accuse transfer theory states that a lightning strike to a protected structure can be prevented by reducing the electrical potential betwixt the protected construction and the thundercloud. This is done past transferring electrical charge (such as from the nearby Earth to the sky or vice versa).^{[26] [27]} Transferring electric charge from the Earth to the sky is done by installing engineered products composed of many points above the structure. It is noted that pointed objects volition indeed transfer charge to the surrounding atmosphere^{[28] [29]} and that a considerable electric current can be measured through the conductors equally ionization occurs at the indicate when an electrical field is present, such as happens when thunderclouds are overhead.

In the United States, the National Fire Protection Association (NFPA) does non currently^{[ when? ]} endorse a device that can prevent or reduce lightning strikes. The NFPA Standards Council, following a request for a project to accost Dissipation Array[tm] Systems and Charge Transfer Systems, denied the request to begin forming standards on such technology (though the Quango did not forestall on time to come standards development subsequently reliable sources demonstrating the validity of the basic technology and science were submitted).^[30]

Early streamer emission (ESE) theory [edit]

ESE lightning rod mounted at the Monastery of St. Nicholas Anapausas (Μονή του Αγίου Νικολάου), Meteora, Greece

The theory of early streamer emission proposes that if a lightning rod has a mechanism producing ionization near its tip, then its lightning capture expanse is greatly increased. At first, small quantities of radioactive isotopes (radium-226 or americium-241) were used as sources of ionization^[31] between 1930 and 1980, later replaced with various electric and electronic devices. Co-ordinate to an early patent, since most lightning protectors' ground potentials are elevated, the path distance from the source to the elevated footing indicate will be shorter, creating a stronger field (measured in volts per unit distance) and that construction volition be more prone to ionization and breakup.^[32]

AFNOR, the French national standardization body, issued a standard, NF C 17-102, roofing this engineering. The NFPA also investigated the subject and there was a proposal to consequence a like standard in the USA. Initially, an NFPA independent third party panel stated that "the [Early Streamer Emission] lightning protection engineering science appears to be technically sound" and that there was an "adequate theoretical basis for the [Early on Streamer Emission] air last concept and design from a physical viewpoint".^[33]) The same panel also concluded that "the recommended [NFPA 781 standard] lightning protection system has never been scientifically or technically validated and the Franklin rod air terminals have not been validated in field tests under thunderstorm conditions".

In response, the American Geophysical Wedlock ended that "[t]he Bryan Panel reviewed essentially none of the studies and literature on the effectiveness and scientific basis of traditional lightning protection systems and was erroneous in its determination that in that location was no basis for the Standard". AGU did not effort to assess the effectiveness of any proposed modifications to traditional systems in its report.^[34] The NFPA withdrew its proposed draft edition of standard 781 due to a lack of prove of increased effectiveness of Early Streamer Emission-based protection systems over conventional air terminals.

Members of the Scientific Committee of the International Conference on Lightning Protection (ICLP) have issued a joint statement stating their opposition to Early Streamer Emission technology.^[35] ICLP maintains a spider web page with information related to ESE and related technologies.^[36] Still, the number of buildings and structures equipped with ESE lightning protection systems is growing equally well equally the number of manufacturers of ESE air terminals from Europe, Americas, Middle Eastward, Russian federation, China, South Korea, ASEAN countries, and Australia.^{[ citation needed ] [37]}

Assay of strikes [edit]

Lightning strikes to a metallic structure tin can vary from leaving no evidence—except, perhaps, a modest pit in the metal—to the consummate destruction of the structure.^[38] When there is no testify, analyzing the strikes is hard. This ways that a strike on an uninstrumented structure must exist visually confirmed, and the random beliefs of lightning renders such observations difficult.^{[38] [39] [twoscore] [41]} There are also inventors working on this problem,^{[42] [43]} such as through a lightning rocket. While controlled experiments may exist off in the future, very good data is being obtained through techniques which utilise radio receivers that sentinel for the characteristic electrical 'signature' of lightning strikes using stock-still directional antennas.^{[44] [45] [46] [47]} Through accurate timing and triangulation techniques, lightning strikes can be located with nifty precision, so strikes on specific objects often tin exist confirmed with confidence.

The energy in a lightning strike is typically in the range of i to ten billion joules. This energy is released usually in a minor number of separate strokes, each with duration of a few tens of microseconds (typically 30 to 50 microseconds), over a period of about 1 fifth of a second. The great majority of the energy is dissipated every bit oestrus, lite and sound in the atmosphere.

Shipping protectors [edit]

Aircraft are protected by devices mounted to the shipping construction and by the design of internal systems. Lightning normally enters and exits an aircraft through the outer surface of its airframe or through a static dischargers. The lightning protection system provides rubber conductive paths between the entry and leave points to forbid damage to electronic equipment and to protect combustible fuel or cargo from sparks.

These paths are constructed of conductive materials. Electrical insulators are only effective in combination with a conductive path because blocked lightning tin easily exceed the breakdown voltage of insulators. Composite materials are synthetic with layers of wire mesh to make them sufficiently conductive and structural joints are protected by making an electrical connectedness beyond the joint.

Shielded cable and conductive enclosures provide the majority of protection to electronic systems. The lightning current emits a magnetic pulse which induces electric current through any loops formed past the cables. The current induced in the shield of a loop creates magnetic flux through the loop in the reverse direction. This decreases the total flux through the loop and the induced voltage around information technology.

The lightning-conductive path and conductive shielding carry the majority of electric current. The remainder is bypassed effectually sensitive electronics using transient voltage suppressors, and blocked using electronic filters in one case the permit-through voltage is depression plenty. Filters, like insulators, are simply effective when lightning and surge currents are able to flow through an alternate path.

Watercraft protectors [edit]

A lightning protection installation on a watercraft comprises a lightning protector mounted on the meridian of a mast or superstructure, and a grounding conductor in contact with the water. Electrical conductors adhere to the protector and run downwards to the conductor. For a vessel with a conducting (fe or steel) hull, the grounding conductor is the hull. For a vessel with a non-conducting hull, the grounding conductor may be retractable, attached to the hull, or attached to a centerboard.

Risk assessment [edit]

Some structures are inherently more than or less at hazard of beingness struck by lightning. The risk for a structure is a part of the size (area) of a construction, the height, and the number of lightning strikes per year per mi² for the region.^[48] For case, a small edifice will be less likely to be struck than a large one, and a building in an area with a loftier density of lightning strikes volition exist more likely to be struck than one in an surface area with a low density of lightning strikes. The National Fire Protection Clan provides a risk assessment worksheet in their lightning protection standard.^[49]

The International Electrotechnical Commission (IEC) lightning risk-assessment comprises four parts: loss of living beings, loss of service to public, loss of cultural heritage, and loss of economic value.^[fifty] Loss of living beings is rated as the near of import and is the only loss taken into consideration for many nonessential industrial and commercial applications.

Standards [edit]

The introduction of lightning protection systems into standards allowed various manufactures to develop protector systems to a multitude of specifications. In that location are multiple international, national, corporate and military lightning protection standards.

• NFPA-780: "Standard for the Installation of Lightning Protection Systems" (2014)
• M440.1-one, Electrical Storms and Lightning Protection, Department of Energy
• AFI 32-1065 – Grounding Systems, U. Due south. Air Strength Space Command
• FAA STD 019e, Lightning and Surge Protection, Grounding, Bonding and Shielding Requirements for Facilities and Electronic Equipment
• UL standards for lightning protection
  • UL 96: "Standard of Lightning Protection Components" (5th Edition, 2005)
  • UL 96A: "Standard for Installation Requirements for Lightning Protection Systems" (Twelfth Edition, 2007)
  • UL 1449: "Standard for Surge Protective Devices" (Fourth Edition, 2014)
• IEC standards
  • EN 61000-iv-5/IEC 61000-4-v: "Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement techniques – Surge immunity test"
  • EN 62305/IEC 62305: "Protection confronting lightning"
  • EN 62561/IEC 62561: "Lightning Protection Organization Components (LPSC)"
• ITU-T K Series recommendations: "Protection against interference"
• IEEE standards for grounding
  • IEEE SA-142-2007: "IEEE Recommended Practice for Grounding of Industrial and Commercial Power Systems". (2007)
  • IEEE SA-1100-2005: "IEEE Recommended Practice for Powering and Grounding Electronic Equipment" (2005)
• AFNOR NF C 17-102 Archived 2015-04-02 at the Wayback Automobile: "Lightning protection – Protection of structures and open up areas confronting lightning using early streamer emission air terminals" (1995)
• GB 50057-2010 Design Lawmaking for Lightning Protection of Buildings
• Equally / NZS 1768:2007: "Lightning protection"

See likewise [edit]

• Grounding kit
• Ground (electricity)
• Václav Prokop Diviš (1698–1765) – Constructor of the starting time grounded lightning rod, in Přímětice u Znojma during 1750–1754.
• James Otis Jr. – Gimmicky of Ben Franklin, killed at doorway past lightning in Andover, Massachusetts on May 23, 1783.
• Apollo 12 – A Saturn Five rocket that was struck by lightning soon after liftoff.
• The Autobiography of Benjamin Franklin#Part Ane
• Lightning rod fashion

References [edit]

Citations [edit]

1. ^ Copper lightning protection systems relieve lives, billions; Building and Architectural News, #80, Winter 1995; "Archived copy". Archived from the original on 2013-03-fifteen. Retrieved 2012-09-11 . {{cite web}}: CS1 maint: archived re-create equally title (link)
2. ^ I. Bernard Cohen, The Two Hundredth Anniversary of Benjamin Franklin's 2 Lightning Experiments and the Introduction of the Lightning Rod, in: Proceedings of the American Philosophical Order, Vol. 96, No. 3. (Jun. 20, 1952), pp. 331–366.
3. ^ "History of Rebar". Whaley Steel. Archived from the original on 2011-11-27.
4. ^ Seckel, Al, and John Edwards, "Franklin's Unholy Lightning Rod Archived 2006-05-26 at the Wayback Car". 1984.
5. ^ See the following 2 articles for alien views of this beingness an independent invention past Diviš:
   Hujer, Karel (Dec 1952). "Father Procopius Diviš — The European Franklin". Isis. 43 (four): 351–357. doi:10.1086/348159. ISSN 0021-1753. JSTOR 227388. S2CID 144939221.
   Cohen, I. Bernard; Schofield, Robert (December 1952). "Did Diviš Erect the First European Protective Lightning Rod, and Was His Invention Independent?". Isis. 43 (4): 358–364. doi:x.1086/348160. ISSN 0021-1753. JSTOR 227389. S2CID 144820851.
6. ^ Recovering Benjamin Franklin: an exploration of a life of scientific discipline and service. Open up Court Publishing. 1999. ISBN978-0-8126-9387-4.
7. ^ "Antique Lightning Rod Ball Hall of Fame". Antique Bottle Collectors Haven. (glass lightning balls collection)
8. ^ Statue of Freedom http://www.aoc.gov/cc/art/freedom.cfm
9. ^ The Point of a Monument: A History of the Aluminum Cap of the Washington Monument: The Functional Purpose
10. ^ NFPA-780 Standard for the Installation of Lightning Protection Systems 2008 Edition
11. ^ Vernon Cooray (ed.) Lightning Protection, The Establishment of Engineering and Applied science, 2010, ISBN 978-1-84919-106-7 pp. 240-260, p 320
12. ^ ^{a b} Benjamin Franklin and Lightning Rods – Physics Today January 2006, Accessed 2008-06-one nine:00pm GMT.
13. ^ NFPA-780 Standard for the Installation of Lightning Protection Systems 2008 Edition – Annex B.3.two.two
14. ^ Sir William Thomson, Papers on Electrostatics and Magnetism.
15. ^ NFPA-780 Standard for the Installation of Lightning Protection Systems 2008 Edition – Annex B – B.4.3
16. ^ NFPA-780 Standard for the Installation of Lightning Protection Systems 2008 Edition – Annex C
17. ^ Donlon, Tim, "Lightning Protection for Celebrated Buildings". Cathedral Communications Limited, 2001.
18. ^ Installation requirements for lightning protection systems – UL 96A 4.7.3.iv.2
19. ^ Lightning protection installation, U.S. Patent 3,919,956
20. ^ Installation requirements for lightning protection systems – UL 96A 8.2.2
21. ^ Standard for the installation of lightning protection systems 2008 edition – NFPA-780 4.8.two.4
22. ^ Ian Godwin (March 26, 2003). "Franklin letter of the alphabet to King fans flames of lightning debate". ABC Science Online. Australian Broadcasting Corporation. Retrieved July 29, 2011.
23. ^ C. B. Moore, William Rison, James Mathis, and Graydon Aulich, "Lightning Rod Comeback Studies". Journal of Applied Meteorology: Vol. 39, No. 5, pp. 593–609. Langmuir Laboratory for Atmospheric Research, New United mexican states Institute of Mining and Technology, Socorro, New Mexico. April 10, 1999.
24. ^ U.Southward. Patent i,266,175, Tesla, "Lightning-Protector".
25. ^ U.South. Patent 3,371,144, Griscom, "Transmission-line lightning-proofing structures". Page 25, Column 5. (cf. […] the charge on a leader as a part of height above ground[…])
26. ^ U.S. Patent half-dozen,307,149, Richard Ralph Zini, et al., Non-contaminating lightning protection arrangement. Claim one and claim ten.
27. ^ John Richard Gumley, U.S. Patent 6,320,119, Lightning air terminals and method of pattern and application
28. ^ Emitter of ions for a lightning rod with a parabolic reflector, Manuel Domingo Varela, U.Due south. Patent 6,069,314.
29. ^ Lightning-protector for electrical conductors, Johathan H. Vail, U.S. Patent 357,050.
30. ^ Casey C. Grant, "To: Interested Parties"
31. ^ B. Charpentier, South. Rodde: "Decommissioning of radioactive lightning rods in France", Autorité de sûreté nucléaire (ASN), March 2012
32. ^ U.S. Patent 1,869,661, Bumbraugh, "Lightning protection system and method".
33. ^ Bryan, R. G., et al., 1999, "Report of the 3rd-Political party Independent Evaluation Panel on the Early Streamer Emission Lightning Protection Technology".
34. ^ Study of The Committee on Atmospheric And Space Electricity of The American Geophysical Matrimony on The Scientific Basis for Traditional Lightning Protection Systems
35. ^ Mousa, Abdul M. "Scientists Oppose Early Streamer Air Terminals", 1999.
36. ^ ICLP ESE result webpage Archived 2013-xi-26 at the Wayback Machine
37. ^ "Statistics - ILPA". Intlpa.org. Archived from the original on 2015-12-24. Retrieved 2015-12-24 .
38. ^ ^{a b} Rakov, et al., Lightning: physics and effects, p. 364
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Sources [edit]

• Vladimir A. Rakov and Martin A. Uman, Lightning: physics and effects. Cambridge Academy Printing, 2003. 698 pages. ISBN 0-521-58327-6.
• J. L. Bryan, R. G. Biermann and M. A. Erickson, "Written report of the Third-Party Independent Evaluation Panel on the Early Streamer Emission Lightning Protection Engineering". National Burn Protection Clan, Quincy, Mass., 1999.
• Kithil, Rich. "More on lightning rods...", Lightning Safety Home Folio, Message #402. May 8, 2000. (Response to C. B. Moore) Originally at: https://portishead-plumbing.co.uk/
• M. A. Uman and V. A. Rakov "Critical Review of Nonconventional Approaches to Lightning Protection", Bulletin of the American Meteorological Lodge, December 2002.
• Mousa, Abdul M. "War of the Lightning Rods", Electricity Today, 2004.
• Zipse, Donald. "Prevent Lightning Strikes with Charge Transfer Systems", Power Quality, Nov 2001
• Zipse, Donald. "Lightning protection methods: An update and a discredited system vindicated", IEEE Trans. on Manufacture Applications, 37, 407–414, 2001.
• Carpenter Jr., Roy B. "Preventing Directly Strikes".

External links [edit]

• "Researchers find that blunt lightning rods work best". U.s.a. Today, June x, 2002.
• Federal Aviation Administration, "FAA-STD-019d, Lightning and surge protection, grounding, bonding and shielding requirements for facilities and electronic equipment Archived 2012-02-12 at the Wayback Automobile". National Transportation Library, August 9, 2002.
• Kithil, Richard, "Lightning Rods: Recent Investigations". National Lightning Safety Institute, September 26, 2005.
• Kithil, Richard, "Should Lightning Rods be Installed?". National Lightning Safety Establish, September 26, 2005.
• Kithil, Richard, "Fundamentals of Lightning Protection". National Lightning Safety Constitute, September 26, 2005.
• Nailen, Richard 50., "Lightning controversy goes on", The Electrical Apparatus, February 2001.
• Lightning Safety Alliance pedagogy folio
• John Scoffern, Orr's Circle of the Sciences, Atmospheric Electricity—Theory of Lightning-rods W. S. Orr 1855.
• February 1919 Popular Scientific discipline article about Lightning Arresters and how they were used in early Ac and DC power distribution systems, "Electrical Devices and How They Work, Part 14: Lightning Arresters", Popular Science monthly, February 1919, 5 unnumbered pages, Scanned by Google Books: https://books.google.com/books?id=7igDAAAAMBAJ&pg=PT17
• "Do lightning rods really piece of work?", The Straight Dope, August 24, 2001
• Scientific American, "Protection From Lightning", 06-Aug-1881, pp.88

What Does Lightning Rods Do,

Source: https://en.wikipedia.org/wiki/Lightning_rod

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