f10.1108/fFacilities0263-2772Emerald Group Publishing Limited10.1108/f.2000.06918jab.019e-non-articleSecondary articleDevelopmentscat-PMBEProperty management & built environmentcat-BCNBuilding & constructioncat-REPReal estate & propertyFrench innovation leads to less lightning damage011020001810/11/12© MCB UP Limited2000Buildings, Safety, European Standards.peer-reviewednoacademic-contentyesrightslinkexcludedFrench innovation leads to less lightning damage

French innovation leads to less lightningdamageKeywords: Buildings, Safety, EuropeanStandards

Every year in France there are two million lightning strikes, killing orinjuring 50 people, several thousand animals, and causing 15,000 fires. A numberof French companies specialise in the design, manufacture and sale of productsdesigned to protect against the direct and indirect effects of lightning.

Lightning conductors have been improved by incorporating ion generators.Ionising lightning conductors produce repeated pulses at their tip, withoutrequiring an external power supply. These have the effect of encouraging anascending discharge, as well as its propagation, during the early stages of thedevelopment of the lightning. Protel, designed the Vega ionising lightningconductor. Stephane Smadia, marketing manager at Protel, says, "Vega is aelectronic ionising lightning conductor. A generator produces an emission ofions synchronised to the ascending tracer. This generator, placed in a sealeddouble metal-clad enclosure made from 316 stainless steel, is being put to thetest in the most severe climatic conditions. It is self-contained and can bechecked, during maintenance, by a tester specifically developed for thislightning conductor. The Vega meets the European standards currently in force."

The company Helita invented the first lightning conductor with a high-voltagepulsed spark-over device: the Pulsar. This device also reduces the time neededfor the formation and propagation of the ascending discharge. The Pulsar emits asignal with a specified and controlled amplitude and frequency. ArnaudBallouhey, export sales manager at Helita, stresses that "the BritishStandards Institution, an independent body, validated the performance of thePulsar, and its consistency over time, by giving it a certificate at the end of1999".

To reinforce the protection of a building against lightning, the building canbe covered by a meshed cage and provided with strike points on the roof, 50cmlong and separated from one another by about 15m. These points are connected bya conductor, in the same way as for earths. On this principle, panels of largesurface area fitted with numerous points, designed to emit charges through theCorona effect, can also act to divert lightning strikes.

The installation of lightning arresters makes it possible to protectelectrical equipment, whether on high or low power networks. The lightningarrester routes the surges to earth before they can penetrate the installation.To ensure good protection, the lightning arrester has to act on surges occurringin common mode (between live or neutral and earth) and in differential mode(between live and neutral).

The choice of lightning arrester depends on two main criteria: the maximumdischarge current (Imax) and the protection level (Up). Imax corresponds to therating of the lightning arrester selected according to the nature of the site tobe protected and the frequency of lightning observed in the area. The greaterthe risk factor, the higher the rating of the arrester needs to be. Whatever thearea concerned, in a rural or industrial environment, a rating of 65kA can bejustified. The Up or residual voltage of the arrester must be suitable for thesensitivity of the equipment to be protected. The lower its value, the better isthe level of protection. The design of lightning arresters allows them, ingeneral, to withstand up to 20 lightning strikes at the rated intensity (and oneat maximum intensity).

The company Franklin France offers a discharge counter. Marie Bakker,assistant general manager, explains that "this tool is a logger designed todetect and count the lightning strikes received by lightning protectionequipment. The safety officer or installer can therefore carry out specificmaintenance on the equipment". Franklin France was already well-known forits Saint Elmo lightning conductor with its piezoelectric ceramic arcingstimulator.

Lightning arresters are now installed systematically for the protection offacilities such as radio relay stations, pumping stations (remote reading), tollbarriers, etc. However, Emmanuel Francôois, marketing manager of SouleProtections Surtensions, says that "the lightning arrester is still, inFrance, a niche market but it is going to expand under the influence of theemergence of electronics into everyday life. As users are becoming more and moreaware of the risks of lightning and the importance of protecting against it, thelightning arrester will tomorrow be as common for surge protection as theearth-leakage circuit-breaker is today for protection against indirect contacts".

Soule has launched a range of arrester sockets and multiple sockets known asDomoFoudre. "This range constitutes a turnkey solution for users requiringbetter overall or local protection for their equipment (televisions,telephones/faxes, computers/Internet). They will be able to install a DomoFoudrepackage that consists of an arrester for the distribution board and terminalprotection". A network of DomoFoudre installers has been set up forindividuals to help them in the selection and installation of the arresters.

An extensive campaign highlighting the importance of electrical safety onfarms in general, and protection against lightning in particular, has beenconducted by Electricite de France, Promotelec (organisation for the promotionof electrical safety), France Telecom and Groupama. This insurance companydecided to invest in prevention by giving help to farmers so that they canincrease the reliability of their installations.

The farming sector has made large investments, particularly in buildings forbattery farming. Automated equipment, particularly for the feeding of animals,is increasing, and information technology is becoming widespread. As thesmallest break in operation can have serious consequences (death of animals),the installation of lightning arresters ensures continuation of operation andtherefore profitability.

For more information please contact Rob Williams at the FTPB. Tel: +44 (0) 207235 5330.