{"id":4474,"date":"2026-09-07T10:43:34","date_gmt":"2026-09-07T02:43:34","guid":{"rendered":"https:\/\/cnkuangya.com\/?p=4474"},"modified":"2026-09-07T16:20:23","modified_gmt":"2026-09-07T08:20:23","slug":"why-spd-connected-in-parallel","status":"publish","type":"post","link":"https:\/\/cnkuangya.com\/fr\/blog\/why-spd-connected-in-parallel\/","title":{"rendered":"Pourquoi un parafoudre est-il connect\u00e9 en parall\u00e8le plut\u00f4t qu'en s\u00e9rie ?"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Si vous examinez une installation typique de parafoudre (SPD), vous remarquerez peut-\u00eatre une diff\u00e9rence par rapport \u00e0 un fusible ou un disjoncteur.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un fusible ou un disjoncteur est normalement install\u00e9 en s\u00e9rie avec le circuit, de sorte que le courant de charge le traverse.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un parafoudre (SPD) de puissance typique est g\u00e9n\u00e9ralement <strong>connect\u00e9 en parall\u00e8le<\/strong> avec le circuit qu'il prot\u00e8ge, c'est pourquoi de nombreux installateurs demandent pourquoi un <strong>SPD est connect\u00e9 en parall\u00e8le au lieu d'\u00eatre en s\u00e9rie<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pourquoi ?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La r\u00e9ponse simple est qu'un parafoudre (SPD) connect\u00e9 en parall\u00e8le n'a pas besoin de supporter le courant de charge normal. Dans des conditions de fonctionnement normales, il reste dans un \u00e9tat \u00e0 haute imp\u00e9dance. Lorsqu'une surtension transitoire se produit, le SPD commence \u00e0 conduire et fournit un chemin \u00e0 faible imp\u00e9dance pour le courant de choc, limitant ainsi la tension atteignant l'\u00e9quipement prot\u00e9g\u00e9.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C'est pourquoi la connexion en parall\u00e8le est largement utilis\u00e9e pour les SPD de type 1 et de type 2 dans les syst\u00e8mes de distribution \u00e9lectrique et photovolta\u00efques.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cependant, \u201c SPD = toujours en parall\u00e8le \u201d n'est pas une r\u00e8gle absolue. Des SPD connect\u00e9s en s\u00e9rie et des filtres de protection contre les surtensions existent \u00e9galement pour certaines applications. Dans cet article, nous traitons principalement du SPD de puissance courant connect\u00e9 en parall\u00e8le utilis\u00e9 dans les syst\u00e8mes de distribution CA et les syst\u00e8mes solaires PV CC.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">R\u00e9ponse rapide : Connexion SPD en parall\u00e8le vs en s\u00e9rie<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Un exemple typique <strong>SPD connect\u00e9 en parall\u00e8le<\/strong> est con\u00e7u pour r\u00e9agir aux \u00e9v\u00e9nements de surtension temporaire sans transporter le courant de fonctionnement normal de la charge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Dans des conditions normales :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Source d'alimentation \u2192 Charge<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Le SPD reste en veille.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Lorsqu'une surtension se produit, le parafoudre modifie son comportement \u00e9lectrique et conduit le courant de surtension \u00e0 travers son chemin de protection, aidant ainsi \u00e0 limiter la tension apparaissant aux bornes des \u00e9quipements sensibles.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un montage en parall\u00e8le simplifi\u00e9 se pr\u00e9sente comme suit :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Source d'alimentation \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Charge\n<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring-1024x683.jpg\" alt=\"SPD parallel connection wiring in an electrical distribution system\" class=\"wp-image-4476\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-parallel-connection-wiring.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Un parafoudre typique connect\u00e9 en parall\u00e8le est install\u00e9 aux bornes du circuit prot\u00e9g\u00e9 plut\u00f4t que directement sur le chemin du courant de charge normal.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Le parafoudre est connect\u00e9 aux bornes du circuit plut\u00f4t qu'ins\u00e9r\u00e9 directement dans le chemin du courant de charge normal. <strong><a href=\"https:\/\/www.phoenixcontact.com\/assets\/c8428ddc-254d-40b8-a2f2-540ac13bd818\/index.html#0\" rel=\"noopener\">Principes fondamentaux de la protection contre les surtensions de Phoenix Contact<\/a><\/strong> explique \u00e9galement que les parafoudres peuvent \u00eatre install\u00e9s en parall\u00e8le avec l'\u00e9quipement prot\u00e9g\u00e9 ou entre les conducteurs concern\u00e9s.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Eaton d\u00e9crit les parafoudres connect\u00e9s en parall\u00e8le, ou en d\u00e9rivation, de la m\u00eame mani\u00e8re : leurs conducteurs de connexion ne transportent pas le courant d'alimentation normal, mais transportent plut\u00f4t le courant de courte dur\u00e9e associ\u00e9 aux \u00e9v\u00e9nements transitoires.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cette diff\u00e9rence fondamentale explique pourquoi la plupart des parafoudres de puissance courants sont install\u00e9s en parall\u00e8le.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-9-16 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"Why is an SPD connected in parallel instead of series?\" width=\"563\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/itkgmV2pQ98?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><figcaption class=\"wp-element-caption\">D\u00e9couvrez comment un parafoudre (SPD) typique se comporte en fonctionnement normal et lors d'une surtension.<\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Que se passe-t-il pour un parafoudre lors d'un fonctionnement normal ?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Pour comprendre le branchement en parall\u00e8le, il est utile de comprendre d'abord ce que fait le parafoudre en l'absence de surtension.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Sous une tension syst\u00e8me normale<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">En fonctionnement normal, la tension du syst\u00e8me reste inf\u00e9rieure au niveau auquel le parafoudre conduit de mani\u00e8re significative.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour un parafoudre \u00e0 base de varistance (MOV), l'\u00e9l\u00e9ment de protection pr\u00e9sente une imp\u00e9dance relativement \u00e9lev\u00e9e dans des conditions de tension normales.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cela signifie que le courant de fonctionnement principal continue de circuler \u00e0 travers le circuit \u00e9lectrique normal vers la charge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Le parafoudre est essentiellement en veille.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Une vue simplifi\u00e9e est :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Alimentation \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Charge\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Cela ne signifie pas n\u00e9cessairement qu'aucun courant ne circule \u00e0 travers chaque SPD. Selon la technologie et la conception du SPD, un faible courant de fuite ou de fonctionnement peut exister.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Le point important est le suivant :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Le courant de charge normal n'a pas besoin de circuler \u00e0 travers un SPD typique connect\u00e9 en parall\u00e8le.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Think of the SPD as a protection path waiting beside the main circuit rather than a component that must continuously carry the equipment&#8217;s operating current.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Que se passe-t-il lorsqu'une surtension survient ?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Une surtension est une augmentation de tension de courte dur\u00e9e qui peut \u00eatre caus\u00e9e par des \u00e9v\u00e9nements tels que des transitoires li\u00e9s \u00e0 la foudre ou des op\u00e9rations de commutation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the voltage across the SPD rises sufficiently, the SPD&#8217;s protection elements begin conducting.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Si vous souhaitez une explication plus approfondie sur la mani\u00e8re dont les \u00e9l\u00e9ments de protection r\u00e9agissent aux surtensions transitoires, consultez notre guide sur <strong><a href=\"https:\/\/cnkuangya.com\/fr\/blog\/how-dc-spd-works-operating-principles-components-engineers-guide\/\">le fonctionnement d'un parafoudre DC<\/a><\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Son imp\u00e9dance diminue fortement par rapport \u00e0 la condition normale.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cela permet au courant de choc de circuler \u00e0 travers le chemin de protection disponible et limite la tension transitoire apparaissant aux bornes de l'\u00e9quipement prot\u00e9g\u00e9.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Une repr\u00e9sentation simplifi\u00e9e est :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>                 \u00c9quipement\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Cependant, ce sch\u00e9ma n'est qu'un exemple simplifi\u00e9.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un parafoudre (SPD) ne <strong>d\u00e9vie pas toujours chaque surtension directement vers la terre<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Selon le syst\u00e8me \u00e9lectrique et la conception du parafoudre (SPD), des modes de protection peuvent exister entre :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Phase et neutre<\/li>\n\n\n\n<li>Phase et terre de protection<\/li>\n\n\n\n<li>Neutre et terre de protection<\/li>\n\n\n\n<li>Phase et phase<\/li>\n\n\n\n<li>Courant continu positif et courant continu n\u00e9gatif<\/li>\n\n\n\n<li>Conducteurs CC et terre de protection (PE)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Pour cette raison, il est plus pr\u00e9cis de dire :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Le parafoudre fournit un chemin contr\u00f4l\u00e9 pour le courant de choc et limite la tension transitoire aux bornes de l'\u00e9quipement qu'il prot\u00e8ge.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Le chemin exact du courant d\u00e9pend de la configuration du parafoudre et de la topologie du syst\u00e8me.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Pourquoi un parafoudre (SPD) est-il connect\u00e9 en parall\u00e8le ?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Pour comprendre pourquoi un parafoudre est connect\u00e9 en parall\u00e8le, il est utile d'examiner ce qui se passe \u00e0 la fois en fonctionnement normal et lors d'une surtension.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Il existe plusieurs raisons importantes pour lesquelles un <strong>SPD connect\u00e9 en parall\u00e8le<\/strong> est largement utilis\u00e9 dans les syst\u00e8mes de distribution \u00e9lectrique.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Le parafoudre n'a pas besoin de supporter le courant de charge normal<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C'est l'une des plus grandes diff\u00e9rences entre un parafoudre et des dispositifs tels qu'un disjoncteur ou un fusible.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imaginez qu'un onduleur fonctionne normalement \u00e0 plusieurs dizaines d'amp\u00e8res.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Avec un parafoudre typique connect\u00e9 en parall\u00e8le, ce courant de fonctionnement ne doit pas passer en continu \u00e0 travers le parafoudre.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Au lieu de cela :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Source \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Charge\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Le parafoudre (SPD) est raccord\u00e9 en parall\u00e8le sur le circuit prot\u00e9g\u00e9.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cela signifie que le parafoudre peut \u00eatre s\u00e9lectionn\u00e9 principalement en fonction des exigences de protection contre les surtensions plut\u00f4t qu'en fonction du courant de fonctionnement total de chaque charge en aval.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Phoenix Contact similarly notes that its parallel-installed power SPDs appear electrically as a branch connected across the power distribution system rather than carrying the circuit&#8217;s normal ampacity.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2. Le parafoudre r\u00e9agit principalement aux \u00e9v\u00e9nements de surtension<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Un parafoudre typique est sensible \u00e0 la tension.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">En pr\u00e9sence d'une tension syst\u00e8me normale, il reste largement inactif.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Lorsqu'une tension transitoire d\u00e9passe sa plage de fonctionnement normale, les \u00e9l\u00e9ments de protection commencent \u00e0 conduire.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cela est fondamentalement diff\u00e9rent d'un fusible, d'un disjoncteur ou d'un interrupteur-sectionneur.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Par exemple :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Fusible<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Source \u2192 Fusible \u2192 Charge\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Disjoncteur<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Source \u2192 Disjoncteur \u2192 Charge\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>SPD en parall\u00e8le typique<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Source \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Charge\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Un fusible ou un disjoncteur doit normalement supporter le courant du circuit car il est physiquement situ\u00e9 sur le chemin de la charge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ce n'est pas le cas d'un SPD en parall\u00e8le.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Le raccordement en parall\u00e8le fournit un chemin pour le courant de surtension<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Le but d'un parafoudre (SPD) n'est pas de \u201c bloquer \u201d chaque surtension avant qu'elle n'atteigne la charge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Au lieu de cela, un parafoudre limiteur de tension r\u00e9agit \u00e0 l'augmentation de la tension transitoire et conduit le courant de surtension.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cette action limite la tension aux bornes du circuit prot\u00e9g\u00e9.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Par exemple, dans un syst\u00e8me photovolta\u00efque simplifi\u00e9 :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Champ PV \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500 Onduleur\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">En fonctionnement normal, l'\u00e9nergie photovolta\u00efque continue vers l'onduleur.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Lors d'un \u00e9v\u00e9nement de surtension, le parafoudre conduit selon son mode de protection et aide \u00e0 maintenir la tension transitoire \u00e0 un niveau inf\u00e9rieur \u00e0 celui qu'elle atteindrait autrement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C'est la raison fondamentale pour laquelle le parafoudre (SPD) est plac\u00e9 en d\u00e9rivation sur le circuit.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">4. Le parafoudre ne fait normalement pas partie du chemin d'alimentation principal.<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c9tant donn\u00e9 qu'un parafoudre typique est connect\u00e9 en d\u00e9rivation, il ne constitue pas le chemin conducteur normal entre la source et la charge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cela pr\u00e9sente un avantage pratique important.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The system&#8217;s normal operating current does not depend on continuously passing through the SPD protection elements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bien entendu, cela ne signifie pas qu'un parafoudre peut \u00eatre ignor\u00e9 apr\u00e8s son installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Les parafoudres peuvent se d\u00e9grader ou se d\u00e9connecter apr\u00e8s une contrainte \u00e9lectrique anormale ; leur \u00e9tat doit donc \u00eatre v\u00e9rifi\u00e9 p\u00e9riodiquement.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Why Isn&#8217;t a Typical SPD Connected in Series?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Comprendre pourquoi un parafoudre est connect\u00e9 en parall\u00e8le permet \u00e9galement d'expliquer pourquoi un parafoudre typique connect\u00e9 en d\u00e9rivation n'est pas plac\u00e9 en s\u00e9rie avec le chemin de charge normal.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Les disjoncteurs et les fusibles sont normalement install\u00e9s en s\u00e9rie car ils doivent supporter le courant du circuit. Un parafoudre typique en parall\u00e8le est con\u00e7u pour une fonction diff\u00e9rente.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Le courant de charge nominal devrait traverser un dispositif en s\u00e9rie<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Une v\u00e9ritable connexion en s\u00e9rie se pr\u00e9sente comme suit :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Source \u2192 Dispositif \u2192 Charge\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Si l'ensemble du parafoudre \u00e9tait ins\u00e9r\u00e9 dans le circuit de charge, il devrait supporter le courant de charge continu.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ses conducteurs, ses bornes, sa conception thermique, sa tenue aux courts-circuits et son comportement en cas de d\u00e9faillance devraient tous \u00eatre con\u00e7us pour cette application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ce n'est pas ainsi qu'un parafoudre de type 1 ou de type 2 sur rail DIN mont\u00e9 en parall\u00e8le est normalement utilis\u00e9.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Les capacit\u00e9s de d\u00e9charge des parafoudres ne sont pas des courants nominaux de charge<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Ceci est un point particuli\u00e8rement important lors de la lecture de la plaque signal\u00e9tique d'un parafoudre.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Supposons qu'un parafoudre soit marqu\u00e9 comme suit :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In = 20 kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">et<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Imax = 40 kA<\/strong><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current-1024x683.jpg\" alt=\"SPD In and Imax surge current ratings compared with normal load current\" class=\"wp-image-4478\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-in-imax-vs-load-current.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">In et Imax d\u00e9crivent la performance du courant de d\u00e9charge de surtension, et non le courant de fonctionnement normal du circuit prot\u00e9g\u00e9.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Si ces caract\u00e9ristiques nominales du parafoudre pr\u00eatent encore \u00e0 confusion, notre <strong><a href=\"https:\/\/cnkuangya.com\/fr\/blog\/dc-spd-specifications\/\">guide des sp\u00e9cifications des parafoudres CC<\/a><\/strong> explique plus en d\u00e9tail Ucpv, In, Imax, Up et Iscpv.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ces chiffres ne <strong>pas<\/strong> signifient pas que le parafoudre est con\u00e7u pour supporter en continu un courant de charge normal de 20 kA ou 40 kA.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour les parafoudres de type 2, <strong>En<\/strong> fait r\u00e9f\u00e9rence au courant de d\u00e9charge nominal associ\u00e9 \u00e0 une impulsion de courant 8\/20 \u03bcs, tandis que <strong>Imax<\/strong> fait r\u00e9f\u00e9rence au courant de d\u00e9charge maximal associ\u00e9 \u00e0 une impulsion 8\/20 \u03bcs.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Phoenix Contact&#8217;s technical definitions likewise describe In and Imax as impulse-current values flowing through the SPD, not normal continuous load-current ratings.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Donc :<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>In et Imax sont des valeurs nominales de courant de d\u00e9charge de surtension. Il ne s'agit pas du courant de fonctionnement normal de la charge.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Cette distinction est tr\u00e8s importante lors de la s\u00e9lection ou de l'explication d'un parafoudre.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Cela signifie-t-il que les parafoudres connect\u00e9s en s\u00e9rie n'existent pas ?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Non.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Il s'agit d'une exception importante.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Bien que les parafoudres de type 1 et de type 2 courants abord\u00e9s dans cet article soient g\u00e9n\u00e9ralement install\u00e9s en parall\u00e8le, il existe \u00e9galement des ensembles de parafoudres connect\u00e9s en s\u00e9rie et des filtres de surtension connect\u00e9s en s\u00e9rie.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Schneider Electric note que les produits connect\u00e9s en s\u00e9rie sont couramment install\u00e9s en ligne \u00e0 proximit\u00e9 de charges sp\u00e9cifiques, tandis que les parafoudres connect\u00e9s en parall\u00e8le constituent l'agencement le plus courant au niveau des tableaux de distribution et des coffrets \u00e9lectriques.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A series-connected product has to be designed specifically to carry the circuit&#8217;s load current.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Par cons\u00e9quent, il serait incorrect de dire :<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u201c Un parafoudre ne peut jamais \u00eatre connect\u00e9 en s\u00e9rie. \u201d<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Une d\u00e9claration techniquement plus pr\u00e9cise est :<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>La plupart des parafoudres de type 1 et de type 2 utilis\u00e9s pour la distribution \u00e9lectrique sont raccord\u00e9s en parall\u00e8le, bien qu'il existe \u00e9galement des produits de protection contre les surtensions con\u00e7us sp\u00e9cifiquement pour un raccordement en s\u00e9rie pour des applications particuli\u00e8res.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">For solar PV and general distribution-board applications, always follow the actual SPD manufacturer&#8217;s wiring diagram.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Raccordement en parall\u00e8le vs en s\u00e9rie : Comparaison simple<\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Le tableau ci-dessous montre comment un appareil typique <strong>SPD connect\u00e9 en parall\u00e8le<\/strong> diff\u00e8re d'un appareil install\u00e9 directement sur le chemin du courant de charge normal.<\/p>\n<\/blockquote>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device-1024x683.jpg\" alt=\"Parallel SPD connection compared with a series-connected electrical device\" class=\"wp-image-4479\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/parallel-spd-vs-series-device.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Un parafoudre typique en parall\u00e8le est raccord\u00e9 aux bornes du circuit prot\u00e9g\u00e9, tandis qu'un appareil raccord\u00e9 en s\u00e9rie est plac\u00e9 directement sur le chemin du courant normal.<\/figcaption><\/figure>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Fonctionnalit\u00e9<\/th><th>Parafoudre typique en parall\u00e8le<\/th><th>Appareil raccord\u00e9 en s\u00e9rie<\/th><\/tr><\/thead><tbody><tr><td>Connect\u00e9 directement dans le circuit de charge normal<\/td><td>Non<\/td><td>Oui<\/td><\/tr><tr><td>Le courant de charge normal traverse l'int\u00e9gralit\u00e9 du dispositif<\/td><td>Non<\/td><td>Oui<\/td><\/tr><tr><td>Disposition courante pour les parafoudres de type 1 \/ type 2<\/td><td>Oui<\/td><td>Moins courant<\/td><\/tr><tr><td>Usage principal<\/td><td>Limite la surtension transitoire en fournissant un chemin pour le courant de foudre<\/td><td>D\u00e9pend de la conception du produit<\/td><\/tr><tr><td>Le courant nominal continu est critique pour l'int\u00e9gralit\u00e9 du dispositif<\/td><td>G\u00e9n\u00e9ralement pas de la m\u00eame mani\u00e8re qu'un dispositif en ligne<\/td><td>Oui<\/td><\/tr><tr><td>La longueur des c\u00e2bles d'installation affecte la protection<\/td><td>Oui<\/td><td>La disposition interne peut r\u00e9duire les effets de la longueur des c\u00e2bles parall\u00e8les externes<\/td><\/tr><tr><td>Applications typiques<\/td><td>Tableaux de distribution, entr\u00e9es d'\u00e9quipement, syst\u00e8mes photovolta\u00efques<\/td><td>Charges sensibles s\u00e9lectionn\u00e9es ou applications sp\u00e9cialis\u00e9es de protection\/filtrage<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Le point important n'est pas qu'une m\u00e9thode soit universellement \u201c bonne \u201d et l'autre \u201c mauvaise \u201d.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Il s'agit d'architectures de produits diff\u00e9rentes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour un parafoudre (SPD) standard sur rail DIN, cependant, le raccordement en parall\u00e8le est g\u00e9n\u00e9ralement la m\u00e9thode d'installation attendue.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Comment un SPD est-il raccord\u00e9 dans un syst\u00e8me photovolta\u00efque CC ?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The same principle applies in many photovoltaic systems, where the SPD is connected in parallel with the DC circuit according to the manufacturer&#8217;s wiring configuration.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system-1024x683.jpg\" alt=\"DC SPD connected in parallel in a solar PV system\" class=\"wp-image-4477\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/dc-spd-parallel-connection-solar-pv-system.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Un SPD CC est g\u00e9n\u00e9ralement raccord\u00e9 en parall\u00e8le avec le circuit photovolta\u00efque selon la configuration du SPD et le sch\u00e9ma de c\u00e2blage du fabricant.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Cependant, le c\u00e2blage des parafoudres (SPD) CC n\u00e9cessite une attention particuli\u00e8re.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Il n'est pas correct de supposer que chaque parafoudre PV est simplement c\u00e2bl\u00e9 comme suit :<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CC+ \u2192 SPD \u2192 PE\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Le circuit de protection interne r\u00e9el peut \u00eatre diff\u00e9rent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Selon le produit et la configuration du syst\u00e8me PV, le SPD peut offrir des modes de protection entre :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CC+ et PE<\/li>\n\n\n\n<li>CC\u2212 et PE<\/li>\n\n\n\n<li>CC+ et CC\u2212<\/li>\n\n\n\n<li>Une combinaison de ces chemins<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Diff\u00e9rents agencements de circuits de parafoudres (SPD) sont utilis\u00e9s selon les syst\u00e8mes de mise \u00e0 la terre et les architectures photovolta\u00efques.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour un parafoudre photovolta\u00efque connect\u00e9 en parall\u00e8le, la disposition exacte des bornes d\u00e9pend toujours de la conception du parafoudre, de la topologie du syst\u00e8me et du sch\u00e9ma de c\u00e2blage du fabricant.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why the wiring diagram printed on the SPD or provided in the manufacturer&#8217;s installation instructions is so important.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour les applications photovolta\u00efques en courant continu, la norme produit d\u00e9di\u00e9e est la CEI 61643-31. DEHN identifie \u00e9galement les normes CEI 60364-7-712 et CEI 60364-5-53 parmi les normes d'installation pertinentes pour les applications photovolta\u00efques et les parafoudres basse tension.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Ne copiez pas un sch\u00e9ma de c\u00e2blage de parafoudre AC pour un parafoudre DC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Bien que les parafoudres AC et DC reposent sur des principes de protection contre les surtensions similaires, les syst\u00e8mes ne sont pas interchangeables.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Les syst\u00e8mes DC pr\u00e9sentent des d\u00e9fis suppl\u00e9mentaires car le courant continu ne poss\u00e8de pas de passage naturel par z\u00e9ro, ce qui rend l'interruption des arcs \u00e9lectriques DC plus difficile.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour cette raison, le parafoudre (SPD) doit \u00eatre sp\u00e9cifiquement adapt\u00e9 \u00e0 la tension continue, \u00e0 la configuration du syst\u00e8me et \u00e0 l'application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Toujours v\u00e9rifier :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tension maximale de fonctionnement en r\u00e9gime permanent<\/li>\n\n\n\n<li>La polarit\u00e9 CC et le marquage des bornes<\/li>\n\n\n\n<li>Le type de parafoudre (SPD)<\/li>\n\n\n\n<li>Les modes de protection<\/li>\n\n\n\n<li>Dispositif de mise \u00e0 la terre<\/li>\n\n\n\n<li>Les exigences en mati\u00e8re de court-circuit<\/li>\n\n\n\n<li>Le sch\u00e9ma de c\u00e2blage du fabricant<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">avant l'installation.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Exemple : Lecture d'un parafoudre DC de type 2 KUANGYA<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">En utilisant un parafoudre DC de type 2 KUANGYA KYPV\/1000 comme exemple, la plaque signal\u00e9tique peut inclure des param\u00e8tres tels que :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Uc = 1000 V DC<\/strong><\/li>\n\n\n\n<li><strong>In = 20 kA<\/strong><\/li>\n\n\n\n<li><strong>Imax = 40 kA<\/strong><\/li>\n\n\n\n<li><strong>Up = 3,5 kV<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">These values describe different parts of the SPD&#8217;s electrical performance.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Uc<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Uc est la tension maximale de r\u00e9gime permanent sp\u00e9cifi\u00e9e pour le parafoudre.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La tension du syst\u00e8me et les conditions de fonctionnement possibles doivent \u00eatre prises en compte lors du choix d'une tension nominale appropri\u00e9e.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">En<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In est le courant de d\u00e9charge nominal.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pour un parafoudre de type 2, il est associ\u00e9 \u00e0 une forme d'onde de courant d'impulsion 8\/20 \u03bcs.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Imax<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Imax est le courant de d\u00e9charge maximal sp\u00e9cifi\u00e9 pour le parafoudre, \u00e9galement associ\u00e9 \u00e0 la forme d'onde 8\/20 \u03bcs pour ce type d'appareil.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imax est \u00e9gal ou sup\u00e9rieur \u00e0 In.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Haut de la page<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Up est le niveau de protection en tension.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Il indique la performance de limitation de tension du parafoudre dans des conditions d'essai sp\u00e9cifi\u00e9es.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The key point for today&#8217;s topic is this:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>20 kA pour In et 40 kA pour Imax ne signifient pas que 20 kA ou 40 kA circulent en continu \u00e0 travers le parafoudre lors d'un fonctionnement normal.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Il s'agit de param\u00e8tres de courant de surtension transitoire.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is another reason why comparing an SPD&#8217;s In or Imax directly with the load current of an inverter is incorrect.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Le raccordement en parall\u00e8le signifie-t-il que la longueur des c\u00e2bles n'a pas d'importance ?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Non.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In fact, connection length is extremely important for a parallel-connected SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A surge has a very fast current rise.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The connecting conductors therefore have inductance, and the rapidly changing surge current can create an additional voltage drop along those conductors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That additional voltage is effectively added to the voltage experienced by the protected equipment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Selon le <strong><a href=\"https:\/\/www.nemasurge.org\/correct-installation-of-hard-wired-surge-protective-device\/\" rel=\"noopener\">NEMA\u2019s guidance on hard-wired SPD installation<\/a><\/strong>, the size and length of the connecting leads can affect the performance of a parallel-connected SPD, and short, direct connections are preferred.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Phoenix Contact makes the same point: long connecting conductors can increase the effective voltage protection level seen in the installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So even if two installations use exactly the same SPD, their real-world protection performance may not be identical if one has much longer connection conductors.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection-1024x768.jpg\" alt=\"Short and long SPD connection leads compared for surge protection\" class=\"wp-image-4480\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection-1024x768.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection-300x225.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection-768x576.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection-16x12.jpg 16w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection-600x450.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-protection.jpg 1448w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Short and direct SPD connections generally reduce additional inductive voltage during fast surge-current events.<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Good Practice<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD connection should generally be:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>As short as practical<\/li>\n\n\n\n<li>As direct as practical<\/li>\n\n\n\n<li>Free from unnecessary loops<\/li>\n\n\n\n<li>Free from unnecessary sharp routing<\/li>\n\n\n\n<li>Installed according to the manufacturer&#8217;s instructions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This is also why SPD location matters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If you want to understand this issue in more detail, see our guide:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><a href=\"https:\/\/cnkuangya.com\/fr\/blog\/spd-distance-from-inverter\/\">La distance entre le parafoudre (SPD) et l'onduleur a-t-elle une importance ?<\/a><\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Where Should an SPD Be Installed?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The exact position depends on the system being protected.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, an SPD may be installed:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>At a main distribution board<\/li>\n\n\n\n<li>At a sub-distribution board<\/li>\n\n\n\n<li>Near sensitive equipment<\/li>\n\n\n\n<li>At the DC input of a PV inverter<\/li>\n\n\n\n<li>Inside or near a PV combiner box<\/li>\n\n\n\n<li>On the AC side of an inverter<\/li>\n\n\n\n<li>At appropriate lightning protection zone boundaries<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If your inverter already includes surge protection, do not assume that an additional external SPD is automatically unnecessary. See <strong><a href=\"https:\/\/cnkuangya.com\/fr\/blog\/solar-inverter-built-in-spd\/\">L'onduleur solaire dispose d'un parafoudre CC int\u00e9gr\u00e9 : avez-vous toujours besoin d'un parafoudre externe ?<\/a><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The objective is not simply to put \u201cone SPD somewhere in the system.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD should be positioned as part of a coordinated protection concept.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For PV systems in particular, cable length and the location of the inverter, modules and building entry points can affect whether additional SPDs are appropriate.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Selon le <strong><a href=\"https:\/\/www.dehn-international.com\/en\/solutions\/photovoltaics\/buildings\" rel=\"noopener\">DEHN\u2019s photovoltaic surge protection guidance<\/a><\/strong>, SPDs should be installed as close as possible to the equipment being protected, such as the inverter, on both the AC and DC sides.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The specific requirements should always be determined from the applicable installation standard, risk assessment and manufacturer instructions.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Does a Parallel-Connected SPD Need a Fuse or Circuit Breaker?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Sometimes yes, but not always in exactly the same way.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is another area where oversimplified advice can cause problems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A parallel SPD may require an external:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Fusible<\/li>\n\n\n\n<li>Disjoncteur<\/li>\n\n\n\n<li>Backup overcurrent protective device<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">depending on the SPD design and installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Other SPDs may include internal protective or disconnecting components.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The correct arrangement depends on factors such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Manufacturer requirements<\/li>\n\n\n\n<li>SPD design<\/li>\n\n\n\n<li>Maximum permitted backup fuse<\/li>\n\n\n\n<li>Available prospective short-circuit current<\/li>\n\n\n\n<li>Tension du syst\u00e8me<\/li>\n\n\n\n<li>Emplacement d'installation<\/li>\n\n\n\n<li>Applicable electrical standard<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker-1024x683.jpg\" alt=\"SPD backup fuse and circuit breaker selection factors\" class=\"wp-image-4481\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-backup-fuse-circuit-breaker.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Backup protection requirements depend on the SPD design, system fault current and manufacturer instructions.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">NEMA specifically advises installers to follow the manufacturer&#8217;s requirements regarding fuses, breakers and connection leads.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, do not assume:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cEvery SPD needs exactly the same backup breaker.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">And do not assume:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cBecause the SPD is connected in parallel, no overcurrent protection is ever required.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Both statements can be wrong.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Always check the SPD datasheet and installation instructions.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Why Short SPD Connections Matter So Much<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Imagine two identical SPDs.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Installation A<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD is mounted very close to the protected equipment, with short and direct conductors.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Installation B<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD is several meters away and connected through long conductors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Although the SPD nameplate is identical, the effective protection at the equipment can be different.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This happens because the connecting conductors contribute additional inductive voltage during a fast surge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">NEMA explains this relationship using:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>V = L \u00d7 di\/dt<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">where:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>V<\/strong> = inductive voltage<\/li>\n\n\n\n<li><strong>L<\/strong> = inductance du conducteur<\/li>\n\n\n\n<li><strong>di\/dt<\/strong> = rate of change of current<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The faster the current changes and the more inductance there is in the connection, the greater the additional voltage can become.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You do not need to calculate this formula for every normal installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La le\u00e7on pratique est beaucoup plus simple :<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Keep SPD connections short and direct.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Common SPD Wiring Mistakes<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes-1024x768.png\" alt=\"Common SPD wiring mistakes in surge protection installations\" class=\"wp-image-4482\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes-1024x768.png 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes-300x225.png 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes-768x576.png 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes-16x12.png 16w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes-600x450.png 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/common-spd-wiring-mistakes.png 1448w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Common SPD installation mistakes include long connection leads, incorrect voltage selection and ignoring manufacturer wiring requirements.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding why the SPD is connected in parallel also makes several common installation mistakes easier to recognize.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Treating a Standard SPD Like a Series Device<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Do not simply place a normal parallel DIN-rail SPD in the main load path unless the manufacturer&#8217;s design specifically requires that configuration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Follow the wiring diagram for the exact product.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">2. Using Excessively Long Connection Wires<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A good SPD with poor wiring may provide worse protection than expected.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Long leads increase inductive voltage during a surge.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Short and direct routing is generally preferred.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">3. Ignoring the Protection and Earthing Arrangement<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Do not assume every surge simply flows from one line terminal to earth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The protection modes depend on the electrical network and SPD design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Correct PE, bonding and circuit connections are essential where required by the product and installation design.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">4. Choosing the Wrong DC Voltage Rating<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">An SPD must be suitable for the voltage that can continuously appear at its terminals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is particularly important in PV systems, where string open-circuit voltage changes with temperature.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Choosing an SPD only because it says \u201cDC SPD\u201d is not enough.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The voltage rating must match the actual PV system design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a step-by-step method, see our <strong><a href=\"https:\/\/cnkuangya.com\/fr\/blog\/dc-spd-selection-guide\/\">DC SPD voltage selection guide for solar PV systems<\/a><\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">5. Confusing In and Imax With Load Current<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This is one of the most common misunderstandings.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An SPD marked:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In = 20 kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">does not mean:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Normal load current = 20 kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In and Imax describe surge-current performance under specified impulse conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They are not normal operating-current ratings.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">6. Ignoring the Manufacturer&#8217;s Backup Protection Requirements<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Do not guess the fuse or breaker size.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Different SPD designs can have different backup protection requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some products also include integrated protective components.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check the actual product documentation.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">7. Installing an SPD but Never Checking It Again<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Many modular SPDs include a visual status indicator.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the indicator shows a fault or replacement condition, the protection module may need to be replaced.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Some SPDs also have remote signaling contacts for connection to alarms, PLCs or monitoring systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Installing the SPD is only the first step.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its condition should also be checked during maintenance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For common warning signs and replacement indicators, see <strong><a href=\"https:\/\/cnkuangya.com\/fr\/blog\/how-to-know-if-an-spd-is-bad\/\">How to Know If an SPD Is Bad?<\/a><\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Parallel SPD vs. Circuit Breaker: What Is the Difference?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A circuit breaker and an SPD protect against different electrical problems.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Disjoncteur<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A circuit breaker is mainly intended to interrupt abnormal current conditions such as overloads or short circuits.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because it must sense and interrupt circuit current, it is connected in series with the load.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">DOCUP<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">An SPD is intended to limit transient overvoltage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical power SPD is connected in parallel so that it can conduct surge current when the transient voltage rises.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That means:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Circuit breaker \u2192 current protection<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>SPD \u2192 transient overvoltage protection<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One cannot normally replace the other.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They perform different jobs.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Parallel SPD vs. Fuse: What Is the Difference?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The same principle applies to a fuse.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A fuse is installed in series with the circuit it protects.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Normal load current passes through the fuse element.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If excessive current persists, the fuse element opens the circuit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical SPD behaves differently.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It remains connected across the protected circuit and responds mainly when the voltage reaches a level that causes its protective elements to conduct.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So although fuses, breakers and SPDs may all appear in the same electrical panel, their functions and connection methods are not the same.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Questions fr\u00e9quemment pos\u00e9es<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Is an SPD Connected in Series or Parallel?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Most common Type 1 and Type 2 power SPDs used in distribution boards and similar applications are connected in parallel with the circuit they protect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, specially designed series-connected SPDs and surge filters also exist.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Always follow the wiring instructions for the exact product.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Why Are Type 1 and Type 2 SPDs Usually Connected in Parallel?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A typical SPD is connected in parallel because it does not need to carry the normal load current.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">During normal voltage conditions, it remains in a high-impedance state.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When a transient overvoltage occurs, it conducts surge current through its protection path and limits the voltage across the protected equipment.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Does Current Normally Flow Through an SPD?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The normal load current does not normally flow through a typical parallel-connected SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, a small leakage or operating current may exist depending on the SPD technology and design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, saying \u201cabsolutely no current flows through an SPD\u201d would not be technically precise.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Does an SPD Send All Surge Current to Ground?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Pas n\u00e9cessairement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An SPD may operate between line and neutral, line and earth, neutral and earth, line and line, or different DC conductors depending on its protection modes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The exact surge-current path depends on the SPD and electrical system configuration.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Can an SPD Be Connected Directly Across the Supply?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Many power SPDs are designed to be connected in parallel across the appropriate conductors of the supply.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, the exact wiring arrangement depends on the SPD type, system earthing arrangement, required overcurrent protection and manufacturer instructions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Never determine the connection from a generic diagram alone.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Why Isn&#8217;t a Typical SPD Installed in Series With the Load?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A normal parallel SPD is not designed to serve as the continuous main load-current path.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Installing an inline device requires a product specifically designed for that purpose, including suitable current, terminal, fault and thermal ratings.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Are In and Imax the Current of the Solar System?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Non.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In and Imax are surge-discharge current parameters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They should not be confused with PV string operating current, short-circuit current or inverter input current.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Is a DC SPD Connected Differently From an AC SPD?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The general surge-protection principle is similar, but DC and AC systems have important differences.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The voltage rating, polarity, protection modes, earthing arrangement and internal SPD design may differ.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For PV systems, always use an SPD intended for the specific DC application and follow its wiring diagram.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Does an SPD Need a Ground Connection?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">It depends on the protection mode and system design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Many power SPDs include protection paths involving PE, but not every surge protection mode is simply conductor-to-earth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Use the manufacturer&#8217;s circuit diagram and the applicable earthing and bonding requirements.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Does SPD Wire Length Affect Protection?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Oui.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Long SPD connection conductors add inductance and can increase the voltage experienced by the protected equipment during a fast transient.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For this reason, connection conductors should generally be kept as short and direct as practical.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Principaux enseignements<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you only remember a few things from this article, remember these:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Most common Type 1 and Type 2 power SPDs are connected in parallel.<\/strong><\/li>\n\n\n\n<li><strong>A parallel-connected SPD does not normally carry the equipment&#8217;s normal load current.<\/strong><\/li>\n\n\n\n<li><strong>During a surge, the SPD conducts surge current through its designed protection path and limits the transient voltage.<\/strong><\/li>\n\n\n\n<li><strong>In and Imax are surge-discharge current ratings, not normal load-current ratings.<\/strong><\/li>\n\n\n\n<li><strong>Not every surge current path is simply \u201cto ground.\u201d The actual path depends on the SPD protection modes and system configuration.<\/strong><\/li>\n\n\n\n<li><strong>Series-connected surge protection products do exist, so \u201cSPDs can never be connected in series\u201d is technically incorrect.<\/strong><\/li>\n\n\n\n<li><strong>Short and direct SPD connections are important because conductor inductance can increase the effective voltage seen by the protected equipment.<\/strong><\/li>\n\n\n\n<li><strong>For PV DC systems, always follow the SPD wiring diagram, voltage rating, system earthing arrangement and manufacturer requirements.<\/strong><\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">So, why is an SPD connected in parallel instead of series?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a typical Type 1 or Type 2 <strong>SPD connect\u00e9 en parall\u00e8le<\/strong>, the normal load current does not pass through the SPD as it would through a series-connected device.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Under normal operating conditions, the SPD remains largely in standby.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When a surge occurs, it conducts through its designed protection path and helps limit the voltage appearing across the protected equipment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is fundamentally different from a fuse or circuit breaker, which normally carries the circuit current and is therefore installed in series.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, correct SPD installation involves more than simply choosing \u201cparallel.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD voltage rating, protection modes, location, conductor length, earthing and bonding arrangement, backup protection and manufacturer wiring diagram all affect the final protection performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For solar PV systems in particular, always use an SPD designed for the relevant DC application and verify the actual system voltage and wiring configuration before installation.<\/p>","protected":false},"excerpt":{"rendered":"<p>If you look at a typical surge protective device (SPD) installation, you may notice something different from a fuse or circuit breaker. A fuse or circuit breaker is normally installed in series with the circuit, so the load current passes through it. A typical power SPD is usually connected in parallel with the circuit it [&hellip;]<\/p>\n","protected":false},"author":7,"featured_media":4475,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-4474","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/posts\/4474","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/comments?post=4474"}],"version-history":[{"count":2,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/posts\/4474\/revisions"}],"predecessor-version":[{"id":4486,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/posts\/4474\/revisions\/4486"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/media\/4475"}],"wp:attachment":[{"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/media?parent=4474"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/categories?post=4474"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnkuangya.com\/fr\/wp-json\/wp\/v2\/tags?post=4474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}