{"id":791,"date":"2023-12-19T16:19:00","date_gmt":"2023-12-19T08:19:00","guid":{"rendered":"https:\/\/www.britecelectric.com\/?post_type=blog&#038;p=791"},"modified":"2024-09-05T16:35:57","modified_gmt":"2024-09-05T08:35:57","slug":"en-62305-protection-against-lightning","status":"publish","type":"blog","link":"https:\/\/www.britecelectric.com\/fr\/blog\/en-62305-protection-against-lightning\/","title":{"rendered":"EN 62305 Protection contre la foudre"},"content":{"rendered":"The EN 62305 standard series specifically cover the protection against lightning to structures, their contents, persons and livestock.\r\n\r\nEN 62305 accepts that we now live in the electronic age, making LEMP (Lightning Electromagnetic Impulse) protection for electronic and electrical systems an integral part of the standard through EN 62305-4. LEMP is the term given to the overall electromagnetic effects of lightning, including conducted surges (transient overvoltage and currents) and radiated electromagnetic field effects.\r\n\r\nEN 62305 \u2013 4 categorizes the source of damage, type of damage and the type of loss.\r\n\r\n<strong>Sources de dommages<\/strong>\r\n\r\nLes dommages pouvant \u00eatre caus\u00e9s par la foudre se subdivisent en :\r\n<ul>\r\n \t<li>Dommages \u00e0 une structure (y compris toutes les lignes \u00e9lectriques a\u00e9riennes et enterr\u00e9es entrantes connect\u00e9es \u00e0 la structure)<\/li>\r\n \t<li>Dommages caus\u00e9s \u00e0 un service (le service faisant ici partie des r\u00e9seaux de t\u00e9l\u00e9communication, de donn\u00e9es, d'alimentation \u00e9lectrique, d'eau, de gaz et de carburant).<\/li>\r\n<\/ul>\r\n<img class=\"wp-image-17873 size-medium aligncenter\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/11-400x271.png\" alt=\"\" width=\"400\" height=\"271\" \/>\r\n\r\n<strong>Types de dommages<\/strong>\r\n\r\nChaque source de dommage peut entra\u00eener un ou plusieurs des trois types de dommages. Les types de dommages possibles sont identifi\u00e9s comme suit\u00a0:\r\n<ul>\r\n \t<li>D1 Blessures de personnes ou de b\u00e9tail dues aux tensions de pas et de contact<\/li>\r\n \t<li>D2 Dommages physiques (incendie, explosion, destruction m\u00e9canique, rejet de produits chimiques) dus aux effets du courant de foudre, y compris les \u00e9tincelles<\/li>\r\n \t<li>D3 D\u00e9faillance des syst\u00e8mes internes due \u00e0 une impulsion \u00e9lectromagn\u00e9tique de foudre (LEMP).<\/li>\r\n<\/ul>\r\n<strong>Types de perte<\/strong>\r\n\r\nLes types de sinistres suivants peuvent r\u00e9sulter de dommages dus \u00e0 la foudre\u00a0:\r\n<ul>\r\n \t<li>L1 Perte de vie humaine<\/li>\r\n \t<li>L2 Perte de service au public<\/li>\r\n \t<li>L3 Perte du patrimoine culturel<\/li>\r\n \t<li>L4 Perte de valeur \u00e9conomique<\/li>\r\n<\/ul>\r\nThe relationships of all of the above parameters:\r\n\r\nThe relationships of all of the above parameters:\r\n<table border=\"1\" cellspacing=\"0\">\r\n<tbody>\r\n<tr class=\"firstRow\">\r\n<td valign=\"top\" width=\"142\">Point de frappe<\/td>\r\n<td valign=\"top\" width=\"142\">Source du dommage<\/td>\r\n<td valign=\"top\" width=\"142\">Type de dommage<\/td>\r\n<td valign=\"top\" width=\"142\">Type de perte<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Structure<\/td>\r\n<td valign=\"top\" width=\"142\">S1<\/td>\r\n<td valign=\"top\" width=\"142\">D1&nbsp;\r\n\r\nD2\r\n\r\nD3<\/td>\r\n<td valign=\"top\" width=\"142\">L1, L4**&nbsp;\r\n\r\nL1, L2, L3, L4\r\n\r\nL1*, L2, L4<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">\u00c0 proximit\u00e9 d'une\u00a0structure<\/td>\r\n<td valign=\"top\" width=\"142\">S2<\/td>\r\n<td valign=\"top\" width=\"142\">D3<\/td>\r\n<td valign=\"top\" width=\"142\">L1*, L2, L4<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Service connect\u00e9 \u00e0 la structure<\/td>\r\n<td valign=\"top\" width=\"142\">S3<\/td>\r\n<td valign=\"top\" width=\"142\">D1&nbsp;\r\n\r\nD2\r\n\r\nD3<\/td>\r\n<td valign=\"top\" width=\"142\">L1,L4**&nbsp;\r\n\r\nL1, L2, L3, L4\r\n\r\nL1*, L2, L4<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Pr\u00e8s d'un service<\/td>\r\n<td valign=\"top\" width=\"142\">S4<\/td>\r\n<td valign=\"top\" width=\"142\">D3<\/td>\r\n<td valign=\"top\" width=\"142\">L1*, L2, L4<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n* Only for structures with risk of explosion and for hospitals or other structures where failures of internal systems immediately endangers human life.\r\n\r\n** Only for properties where animals may be lost.\r\n\r\nLEMP damage is so prevalent that it is identified as one of the specific types (D3) against which protection should be provided and can occur from ALL strike points to the structure or connected services \u2013 direct or indirect. This extended approach also takes into account the danger of fire or explosion associated with services connected to the structure, e.g. power, telecoms and other metallic lines.\r\n\r\nEN 62305 makes it clear that structural lightning protection must no longer be considered in isolation from transient overvoltage\/surge protection and given that lightning from all strikes points, direct or indirect, to the structure or connected services creates a risk from transients, SPDs are a vital means of protection whether structural lightning protection is present or not.\r\n\r\n<strong>Formes d'onde de courant et de tension<\/strong>\r\n\r\nEN 62305 takes account of protection measures on metallic service lines (typically power, signal and telecom lines) using transient overvoltage or Surge Protection Devices (SPDs) against both direct lightning strikes as well as the more common indirect lightning strikes and switching transients. Standards such as the EN 61643 series define the characteristics of lightning currents and voltages to enable reliable and repeatable testing of SPDs (as well as lightning protection components). Although these waveforms may differ from actual transients, the standardized forms are based upon years of observation and measurement (and in some cases simulation). In general they provide a fair approximation of the real world transient.\r\n\r\nTransient waveforms have a fast rising edge and a longer tail. They are described through their peak value (or magnitude), rise time and their duration (or fall time). The duration is measured as the time taken for the test transient to decay to half its peak value.\r\n\r\nThe figures below illustrate the common current and voltage waveforms that are used to test SPDs for mains, signal and telecom lines.\r\n\r\n<img class=\"wp-image-17874 size-medium aligncenter\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-400x239.png\" sizes=\"(max-width: 400px) 100vw, 400px\" srcset=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-400x239.png 400w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-768x459.png 768w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-600x358.png 600w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-150x90.png 150w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12.png 1147w\" alt=\"\" width=\"400\" height=\"239\" \/>\r\n\r\n<strong>Frappes directes<\/strong>\r\n\r\nLa foudre directe peut injecter des courants de foudre partiels de forme d'onde 10\/350 \u03bcs dans un syst\u00e8me o\u00f9 une structure dot\u00e9e d'un syst\u00e8me structurel de protection contre la foudre re\u00e7oit un impact direct (Source S1) ou lorsque la foudre frappe directement une ligne de service a\u00e9rienne (Source S3).\r\n\r\n<strong>Gr\u00e8ves indirectes<\/strong>\r\n\r\nRemote or indirect lightning flashes near the structure (Source S2) or near a connected service to the structure (Source S4) of up to 1km radius away (and hence far more common) are represented by the 8\/20\u03bcs waveform. Induced surges from direct lightning flashes and switching sources are also represented by this waveform. With a much shorter decay or fall time relative to the 10\/350\u03bcs waveform, the 8\/20\u03bcs waveform presents significantly less energy (for an equivalent peak current) but is still devastating enough to damage electrical and electronic equipment.\r\n\r\nEN 62305-1 recognizes that failure of internal systems (Damage Type D3) due to Lightning Electromagnetic Impulse (LEMP) is possible from all points of strike to the structure or service \u2013 direct or indirect (all Sources: S1, S2, S3 and S4).\r\n\r\n<strong>Mesures de protection contre les surtensions (SPM)<\/strong>\r\n\r\nEN 62305-4 describes a number of measures to minimize the severity of transient overvoltage caused by lightning and electrical switching.\r\n\r\nKey and basic protection measures are:\r\n<ul>\r\n \t<li>Mise \u00e0 la terre et liaison<\/li>\r\n \t<li>Blindage \u00e9lectromagn\u00e9tique et acheminement des lignes<\/li>\r\n \t<li>Dispositifs de protection contre les surtensions coordonn\u00e9s<\/li>\r\n<\/ul>\r\nD'autres mesures de protection suppl\u00e9mentaires comprennent\u00a0:\r\n<ul>\r\n \t<li>Extensions du LPS structurel<\/li>\r\n \t<li>Emplacement de l'\u00e9quipement<\/li>\r\n \t<li>Utilisation de c\u00e2bles \u00e0 fibres optiques (protection par isolation)<\/li>\r\n<\/ul>\r\nSPMs also have to operate within and withstand the environment in which they are located considering factors such as temperature, humidity, vibration, voltage and current.\r\n\r\nSelection of the most suitable SPM is made using the risk assessment in accordance with EN 62305-2 taking into account both technical and economic factors. For example, it may not be practical or cost effective to implement electromagnetic shielding measures in an existing structure so the use of coordinated SPDs may be more suitable. Ideally SPDs are best incorporated at the project design stage, although they can also be readily installed in existing installations.\r\n\r\nTo ensure continuous operation of critical systems even in the event of a direct strike, SPDs are essential and these must be suitably deployed, based on the source of surge and its intensity using the Lightning Protection Zones (LPZ) concept within EN 62305-4.\r\n\r\n<strong>Le concept de zone de protection contre la foudre (LPZ)<\/strong>\r\n\r\nLa protection contre le LEMP repose sur un concept de Zone de Protection contre la Foudre (LPZ) qui divise l'ouvrage en question en plusieurs zones selon le niveau de menace pos\u00e9 par le LEMP. L'id\u00e9e g\u00e9n\u00e9rale est d'identifier ou de cr\u00e9er des zones au sein de la structure o\u00f9 l'exposition \u00e0 tout ou partie des effets de la foudre est moindre et de les coordonner avec les caract\u00e9ristiques d'immunit\u00e9 des \u00e9quipements \u00e9lectriques ou \u00e9lectroniques install\u00e9s dans la zone. Les zones successives sontcaract\u00e9ris\u00e9 par des r\u00e9ductions significatives de la gravit\u00e9 du LEMP gr\u00e2ce \u00e0 la liaison, au blindage ou \u00e0 l'utilisation de SPD.\r\n\r\n<strong>Zones externes\u00a0:<\/strong>\r\n<ul>\r\n \t<li>LPZ 0A est la zone soumise aux coups de foudre directs et peut donc devoir transporter jusqu'\u00e0 la totalit\u00e9 du courant de foudre. Il s\u2019agit g\u00e9n\u00e9ralement de la surface du toit d\u2019une structure sans protection structurelle contre la foudre. Le champ \u00e9lectromagn\u00e9tique complet se produit ici.<\/li>\r\n \t<li>LPZ 0B est la zone non soumise aux coups de foudre directs et correspond g\u00e9n\u00e9ralement aux parois lat\u00e9rales d'une structure ou d'un toit dot\u00e9 d'une protection structurelle contre la foudre. Cependant, le champ \u00e9lectromagn\u00e9tique complet s'y produit toujours et des courants de foudre conduits, partiels ou induits, ainsi que des surtensions de commutation peuvent s'y produire.<\/li>\r\n<\/ul>\r\n<strong>Zones internes\u00a0:<\/strong>\r\n<ul>\r\n \t<li>LPZ 1 est la zone interne soumise aux courants de foudre partiels. Les courants de foudre conduits et\/ou les surtensions de commutation sont r\u00e9duits par rapport aux zones externes LPZ 0A, LPZ 0B, tout comme le champ \u00e9lectromagn\u00e9tique si des mesures de blindage appropri\u00e9es sont utilis\u00e9es. Il s\u2019agit g\u00e9n\u00e9ralement de la zone o\u00f9 les services entrent dans la structure ou o\u00f9 se trouve le tableau \u00e9lectrique principal.<\/li>\r\n \t<li>LPZ 2 est une zone interne situ\u00e9e en outre \u00e0 l'int\u00e9rieur de la structure, o\u00f9 les restes de courants de choc de foudre et\/ou de surtensions de commutation sont r\u00e9duits par rapport au LPZ 1. De m\u00eame, le champ \u00e9lectromagn\u00e9tique est encore r\u00e9duit si des mesures de blindage appropri\u00e9es sont utilis\u00e9es. Il s'agit g\u00e9n\u00e9ralement d'une pi\u00e8ce blind\u00e9e ou, pour l'alimentation secteur au niveau de la zone du tableau de distribution secondaire.<\/li>\r\n<\/ul>","protected":false},"featured_media":792,"parent":0,"menu_order":180,"template":"","meta":{"_acf_changed":false},"blog_category":[8],"class_list":["post-791","blog","type-blog","status-publish","has-post-thumbnail","hentry","blog_category-company-news"],"acf":{"des":"The EN 62305 standard series specifically cover the protection against lightning to structures, their contents, persons and livestock.","txt":"The EN 62305 standard series specifically cover the protection against lightning to structures, their contents, persons and livestock.\r\n\r\nEN 62305 accepts that we now live in the electronic age, making LEMP (Lightning Electromagnetic Impulse) protection for electronic and electrical systems an integral part of the standard through EN 62305-4. LEMP is the term given to the overall electromagnetic effects of lightning, including conducted surges (transient overvoltage and currents) and radiated electromagnetic field effects.\r\n\r\nEN 62305 \u2013 4 categorizes the source of damage, type of damage and the type of loss.\r\n\r\n<strong>Sources of damage<\/strong>\r\n\r\nDamage that can be caused by lightning is sub-divided into:\r\n<ul>\r\n \t<li>Damage to a structure (including all incoming electrical overhead and buried lines connected to the structure)<\/li>\r\n \t<li>Damage to a service (service in this instance being part of telecommunication, data, electrical supply, water, gas and fuel distribution networks).<\/li>\r\n<\/ul>\r\n<img class=\"wp-image-17873 size-medium aligncenter\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/11-400x271.png\" alt=\"\" width=\"400\" height=\"271\" \/>\r\n\r\n<strong>Types of damage<\/strong>\r\n\r\nEach source of damage may result in one or more of three types of damage. The possible types of damage are identified as follows:\r\n<ul>\r\n \t<li>D1 Injury of persons or livestock due to step and touch voltages<\/li>\r\n \t<li>D2 Physical damage (fire, explosion, mechanical destruction, chemical release) due to lightning current effects including sparking<\/li>\r\n \t<li>D3 Failure of internal systems due to Lightning Electromagnetic Impulse (LEMP).<\/li>\r\n<\/ul>\r\n<strong>Types of loss<\/strong>\r\n\r\nThe following types of loss may result from damage due to lightning:\r\n<ul>\r\n \t<li>L1 Loss of human life<\/li>\r\n \t<li>L2 Loss of service to the public<\/li>\r\n \t<li>L3 Loss of cultural heritage<\/li>\r\n \t<li>L4 Loss of economic value<\/li>\r\n<\/ul>\r\nThe relationships of all of the above parameters:\r\n\r\nThe relationships of all of the above parameters:\r\n<table border=\"1\" cellspacing=\"0\">\r\n<tbody>\r\n<tr class=\"firstRow\">\r\n<td valign=\"top\" width=\"142\">Point of strike<\/td>\r\n<td valign=\"top\" width=\"142\">Source of\u00a0damage<\/td>\r\n<td valign=\"top\" width=\"142\">Type of\u00a0damage<\/td>\r\n<td valign=\"top\" width=\"142\">Type of\u00a0loss<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Structure<\/td>\r\n<td valign=\"top\" width=\"142\">S1<\/td>\r\n<td valign=\"top\" width=\"142\">D1&nbsp;\r\n\r\nD2\r\n\r\nD3<\/td>\r\n<td valign=\"top\" width=\"142\">L1, L4**&nbsp;\r\n\r\nL1, L2, L3, L4\r\n\r\nL1*, L2, L4<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Near a\u00a0Structure<\/td>\r\n<td valign=\"top\" width=\"142\">S2<\/td>\r\n<td valign=\"top\" width=\"142\">D3<\/td>\r\n<td valign=\"top\" width=\"142\">L1*, L2, L4<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Service connected\u00a0to the structure<\/td>\r\n<td valign=\"top\" width=\"142\">S3<\/td>\r\n<td valign=\"top\" width=\"142\">D1&nbsp;\r\n\r\nD2\r\n\r\nD3<\/td>\r\n<td valign=\"top\" width=\"142\">L1,L4**&nbsp;\r\n\r\nL1, L2, L3, L4\r\n\r\nL1*, L2, L4<\/td>\r\n<\/tr>\r\n<tr>\r\n<td valign=\"top\" width=\"142\">Near a service<\/td>\r\n<td valign=\"top\" width=\"142\">S4<\/td>\r\n<td valign=\"top\" width=\"142\">D3<\/td>\r\n<td valign=\"top\" width=\"142\">L1*, L2, L4<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n* Only for structures with risk of explosion and for hospitals or other structures where failures of internal systems immediately endangers human life.\r\n\r\n** Only for properties where animals may be lost.\r\n\r\nLEMP damage is so prevalent that it is identified as one of the specific types (D3) against which protection should be provided and can occur from ALL strike points to the structure or connected services \u2013 direct or indirect. This extended approach also takes into account the danger of fire or explosion associated with services connected to the structure, e.g. power, telecoms and other metallic lines.\r\n\r\nEN 62305 makes it clear that structural lightning protection must no longer be considered in isolation from transient overvoltage\/surge protection and given that lightning from all strikes points, direct or indirect, to the structure or connected services creates a risk from transients, SPDs are a vital means of protection whether structural lightning protection is present or not.\r\n\r\n<strong>Current and voltage waveforms<\/strong>\r\n\r\nEN 62305 takes account of protection measures on metallic service lines (typically power, signal and telecom lines) using transient overvoltage or Surge Protection Devices (SPDs) against both direct lightning strikes as well as the more common indirect lightning strikes and switching transients. Standards such as the EN 61643 series define the characteristics of lightning currents and voltages to enable reliable and repeatable testing of SPDs (as well as lightning protection components). Although these waveforms may differ from actual transients, the standardized forms are based upon years of observation and measurement (and in some cases simulation). In general they provide a fair approximation of the real world transient.\r\n\r\nTransient waveforms have a fast rising edge and a longer tail. They are described through their peak value (or magnitude), rise time and their duration (or fall time). The duration is measured as the time taken for the test transient to decay to half its peak value.\r\n\r\nThe figures below illustrate the common current and voltage waveforms that are used to test SPDs for mains, signal and telecom lines.\r\n\r\n<img class=\"wp-image-17874 size-medium aligncenter\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-400x239.png\" sizes=\"(max-width: 400px) 100vw, 400px\" srcset=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-400x239.png 400w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-768x459.png 768w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-600x358.png 600w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12-150x90.png 150w, https:\/\/www.britecelectric.com\/wp-content\/uploads\/2023\/12\/12.png 1147w\" alt=\"\" width=\"400\" height=\"239\" \/>\r\n\r\n<strong>Direct strikes<\/strong>\r\n\r\nDirect lightning can inject partial lightning currents of the 10\/350\u03bcs waveform into a system where a structure with a structural Lightning Protection System receives a direct strike (Source S1) or where lightning directly strikes an overhead service line (Source S3).\r\n\r\n<strong>Indirect strikes<\/strong>\r\n\r\nRemote or indirect lightning flashes near the structure (Source S2) or near a connected service to the structure (Source S4) of up to 1km radius away (and hence far more common) are represented by the 8\/20\u03bcs waveform. Induced surges from direct lightning flashes and switching sources are also represented by this waveform. With a much shorter decay or fall time relative to the 10\/350\u03bcs waveform, the 8\/20\u03bcs waveform presents significantly less energy (for an equivalent peak current) but is still devastating enough to damage electrical and electronic equipment.\r\n\r\nEN 62305-1 recognizes that failure of internal systems (Damage Type D3) due to Lightning Electromagnetic Impulse (LEMP) is possible from all points of strike to the structure or service \u2013 direct or indirect (all Sources: S1, S2, S3 and S4).\r\n\r\n<strong>Surge Protection Measures (SPM)<\/strong>\r\n\r\nEN 62305-4 describes a number of measures to minimize the severity of transient overvoltage caused by lightning and electrical switching.\r\n\r\nKey and basic protection measures are:\r\n<ul>\r\n \t<li>Earthing and bonding<\/li>\r\n \t<li>Electromagnetic shielding and line routing<\/li>\r\n \t<li>Coordinated Surge Protective Devices<\/li>\r\n<\/ul>\r\nFurther additional protection measures include:\r\n<ul>\r\n \t<li>Extensions to the structural LPS<\/li>\r\n \t<li>Equipment location<\/li>\r\n \t<li>Use of fiber optic cables (protection by isolation)<\/li>\r\n<\/ul>\r\nSPMs also have to operate within and withstand the environment in which they are located considering factors such as temperature, humidity, vibration, voltage and current.\r\n\r\nSelection of the most suitable SPM is made using the risk assessment in accordance with EN 62305-2 taking into account both technical and economic factors. For example, it may not be practical or cost effective to implement electromagnetic shielding measures in an existing structure so the use of coordinated SPDs may be more suitable. Ideally SPDs are best incorporated at the project design stage, although they can also be readily installed in existing installations.\r\n\r\nTo ensure continuous operation of critical systems even in the event of a direct strike, SPDs are essential and these must be suitably deployed, based on the source of surge and its intensity using the Lightning Protection Zones (LPZ) concept within EN 62305-4.\r\n\r\n<strong>The Lightning Protection Zone (LPZ) concept<\/strong>\r\n\r\nProtection against LEMP is based on a concept of the Lightning Protection Zone (LPZ) that divides the structure in question into a number of zones according to the level of threat posed by the LEMP. The general idea is to identify or create zones within the structure where there is less exposure to some or all of the effects of lightning and to coordinate these with the immunity characteristics of the electrical or electronic equipment installed within the zone. Successive zones are characterized by significant reductions in LEMP severity as a result of bonding, shielding or the use of SPDs.\r\n\r\n<strong>External zones:<\/strong>\r\n<ul>\r\n \t<li>LPZ 0A is the area subject to direct lightning strokes and therefore may have to carry up to the full lightning current. This is typically the roof area of a structure without structural lightning protection. The full electromagnetic field occurs here.<\/li>\r\n \t<li>LPZ 0B is the area not subject to direct lightning strokes and is typically the sidewalls of a structure or a roof with structural lightning protection. However the full electromagnetic field still occurs here and conducted partial or induced lightning currents and switching surges can occur here.<\/li>\r\n<\/ul>\r\n<strong>Internal zones:<\/strong>\r\n<ul>\r\n \t<li>LPZ 1 is the internal area that is subject to partial lightning currents. The conducted lightning currents and\/or switching surges are reduced compared with the external zones LPZ 0A, LPZ 0B as is the electromagnetic field if suitable shielding measures are employed. This is typically the area where services enter the structure or where the main power switchboard is located.<\/li>\r\n \t<li>LPZ 2 is an internal area that is further located inside the structure where the remnants of lightning impulse currents and\/or switching surges are reduced compared with LPZ 1. Similarly the electromagnetic field is further reduced if suitable shielding measures are employed. This is typically a screened room or, for mains power at the sub-distribution board area.<\/li>\r\n<\/ul>"},"_links":{"self":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/blog\/791","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/media\/792"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/media?parent=791"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/blog_category?post=791"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}