{"id":4413,"date":"2026-09-02T15:59:03","date_gmt":"2026-09-02T07:59:03","guid":{"rendered":"https:\/\/cnkuangya.com\/?p=4413"},"modified":"2026-09-03T12:03:33","modified_gmt":"2026-09-03T04:03:33","slug":"spd-distance-from-inverter","status":"publish","type":"post","link":"https:\/\/cnkuangya.com\/pt\/blog\/spd-distance-from-inverter\/","title":{"rendered":"A dist\u00e2ncia entre o DPS e o inversor \u00e9 importante?"},"content":{"rendered":"<p class=\"wp-block-paragraph\"><strong>A dist\u00e2ncia do DPS em rela\u00e7\u00e3o ao inversor \u00e9 uma parte importante do projeto de prote\u00e7\u00e3o contra surtos em sistemas fotovoltaicos, especialmente quando o DPS \u00e9 instalado em uma caixa de jun\u00e7\u00e3o ou pr\u00f3ximo ao arranjo fotovoltaico.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Voc\u00ea instalou um dispositivo de prote\u00e7\u00e3o contra surtos (DPS) CC no sistema fotovoltaico, mas o DPS est\u00e1 dentro da caixa de jun\u00e7\u00e3o enquanto o inversor est\u00e1 a 20 ou 30 metros de dist\u00e2ncia.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Segue uma pergunta muito pr\u00e1tica:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Esse DPS ainda \u00e9 suficiente para proteger o inversor?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ou deveria ser instalado outro DPS mais pr\u00f3ximo ao inversor?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A resposta \u00e9:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Sim, a dist\u00e2ncia \u00e9 importante.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Em um sistema fotovoltaico, a prote\u00e7\u00e3o contra surtos n\u00e3o \u00e9 determinada apenas pela exist\u00eancia de um DPS em algum ponto do circuito CC. A dist\u00e2ncia entre o arranjo fotovoltaico e o inversor, a localiza\u00e7\u00e3o do DPS, o comprimento dos condutores de conex\u00e3o do DPS, a tens\u00e3o suport\u00e1vel de impulso do equipamento e o arranjo de prote\u00e7\u00e3o contra descargas atmosf\u00e9ricas afetam o conceito final de prote\u00e7\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/30774\" rel=\"noopener\">IEC 61643-32<\/a> aborda especificamente a sele\u00e7\u00e3o, instala\u00e7\u00e3o e coordena\u00e7\u00e3o de DPS utilizados em instala\u00e7\u00f5es fotovoltaicas de at\u00e9 1.500 V CC. Ele distingue entre curtas e longas dist\u00e2ncias entre os m\u00f3dulos fotovoltaicos e o inversor, e estabelece requisitos espec\u00edficos para o posicionamento do DPS.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Portanto, a pergunta correta n\u00e3o \u00e9 simplesmente:<\/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\">\u201cEu j\u00e1 possuo um DPS?\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c9:<\/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>\u201cO DPS est\u00e1 instalado no local correto para proteger o equipamento que me interessa?\u201d<\/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\">Resposta r\u00e1pida<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Para instala\u00e7\u00f5es fotovoltaicas abrangidas pelas configura\u00e7\u00f5es relevantes na norma IEC 61643-32:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>quando a dist\u00e2ncia do percurso do cabo entre os m\u00f3dulos fotovoltaicos e o inversor for <strong>inferior a 10 m<\/strong>, um conjunto de DPS pode ser suficiente, desde que as condi\u00e7\u00f5es de prote\u00e7\u00e3o aplic\u00e1veis sejam satisfeitas;<\/li>\n\n\n\n<li>quando essa dist\u00e2ncia for <strong>10 m ou mais<\/strong>, a norma IEC 61643-32 estabelece que dois conjuntos de DPS s\u00e3o necess\u00e1rios para proteger suficientemente tanto os m\u00f3dulos fotovoltaicos quanto o inversor para as configura\u00e7\u00f5es abrangidas pelas Cl\u00e1usulas 6.2.1 e 6.2.2;<\/li>\n\n\n\n<li>onde um sistema de prote\u00e7\u00e3o contra descargas atmosf\u00e9ricas externo estiver presente e a dist\u00e2ncia de separa\u00e7\u00e3o necess\u00e1ria n\u00e3o puder ser mantida, os requisitos de prote\u00e7\u00e3o s\u00e3o mais rigorosos, e o segundo DPS no inversor \u00e9 obrigat\u00f3rio na configura\u00e7\u00e3o abordada pela Cl\u00e1usula 6.2.3.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Ao mesmo tempo, n\u00e3o confunda isto <strong>Dist\u00e2ncia de sistema de 10 m<\/strong> com aproximadamente <strong>Recomenda\u00e7\u00e3o de 0,5 m para o cabo de conex\u00e3o do DPS<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Eles descrevem dois problemas el\u00e9tricos diferentes.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Principais conclus\u00f5es<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Pergunta<\/th><th>Resposta Pr\u00e1tica<\/th><\/tr><\/thead><tbody><tr><td>A dist\u00e2ncia entre o arranjo fotovoltaico e o inversor importa?<\/td><td>Sim<\/td><\/tr><tr><td>10 m \u00e9 uma regra de marketing arbitr\u00e1ria?<\/td><td>N\u00e3o. Ela aparece explicitamente na norma IEC 61643-32<\/td><\/tr><tr><td>\u226510 m significa sempre a mesma coisa em todos os pa\u00edses e instala\u00e7\u00f5es?<\/td><td>N\u00e3o. A norma aplic\u00e1vel, a condi\u00e7\u00e3o LPS, as regras nacionais e a configura\u00e7\u00e3o do sistema continuam a ser importantes.<\/td><\/tr><tr><td>0,5 m \u00e9 a dist\u00e2ncia m\u00e1xima entre o DPS e o inversor?<\/td><td>N\u00e3o<\/td><\/tr><tr><td>A que se refere 0,5 m?<\/td><td>Aos condutores de liga\u00e7\u00e3o do DPS no esquema de cablagem aplic\u00e1vel.<\/td><\/tr><tr><td>Um DPS integrado no inversor pode fazer parte do segundo est\u00e1gio de prote\u00e7\u00e3o?<\/td><td>Potencialmente, se a sua especifica\u00e7\u00e3o e instala\u00e7\u00e3o satisfizerem a fun\u00e7\u00e3o de prote\u00e7\u00e3o necess\u00e1ria.<\/td><\/tr><tr><td>Um Imax maior pode compensar uma m\u00e1 coloca\u00e7\u00e3o do DPS?<\/td><td>N\u00e3o<\/td><\/tr><tr><td>O valor Up isolado indica a tens\u00e3o a que o inversor estar\u00e1 sujeito?<\/td><td>N\u00e3o. A cablagem da instala\u00e7\u00e3o tamb\u00e9m contribui para a tens\u00e3o durante um surto.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Por que a dist\u00e2ncia do DPS em rela\u00e7\u00e3o ao inversor \u00e9 importante?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Um equ\u00edvoco comum \u00e9 considerar que o cabo de cobre \u00e9 eletricamente insignificante durante um surto.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Na frequ\u00eancia de opera\u00e7\u00e3o normal ou em corrente cont\u00ednua est\u00e1vel, essa suposi\u00e7\u00e3o pode parecer razo\u00e1vel.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Um surto relacionado com descargas atmosf\u00e9ricas \u00e9 diferente.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A corrente de surto altera-se extremamente r\u00e1pido. Todo condutor possui indut\u00e2ncia e, quando a corrente varia rapidamente atrav\u00e9s dessa indut\u00e2ncia, desenvolve-se uma tens\u00e3o nos terminais do condutor.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A rela\u00e7\u00e3o b\u00e1sica \u00e9:<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u0394U = L \u00d7 di\/dt<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Onde:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0394U<\/strong> = tens\u00e3o indutiva adicional atrav\u00e9s do condutor<br><strong>L<\/strong> = indut\u00e2ncia do condutor<br><strong>di\/dt<\/strong> = taxa de varia\u00e7\u00e3o da corrente de surto<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Esta equa\u00e7\u00e3o n\u00e3o \u00e9 exclusiva da prote\u00e7\u00e3o contra surtos. \u00c9 uma rela\u00e7\u00e3o eletromagn\u00e9tica b\u00e1sica.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Para a instala\u00e7\u00e3o de DPS, no entanto, ela explica algo muito importante:<\/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>O condutor conectado ao DPS torna-se parte do circuito de prote\u00e7\u00e3o contra surtos.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><a href=\"https:\/\/www.phoenixcontact.com\/en-us\/technologies\/surge-protection-technology\/surge-protection-installation\" rel=\"noopener\">Phoenix Contact&#8217;s surge protection installation guidance<\/a><\/strong> fornece um exemplo ilustrativo usando aproximadamente 1 \u00b5H\/m de indut\u00e2ncia do condutor. Com uma varia\u00e7\u00e3o de corrente de 10 kA em 10 \u00b5s, aproximadamente 1 kV pode se desenvolver atrav\u00e9s de um metro de condutor. Esta \u00e9 uma ilustra\u00e7\u00e3o, e n\u00e3o um valor de projeto universal, pois a indut\u00e2ncia real depende da geometria e do roteamento do condutor.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c9 por isso que os fabricantes de DPS enfatizam repetidamente a necessidade de conex\u00f5es curtas e diretas.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Up n\u00e3o \u00e9 necessariamente a tens\u00e3o vista pelo inversor<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Suponha que a ficha t\u00e9cnica de um DPS indique:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N\u00edvel de prote\u00e7\u00e3o de tens\u00e3o Up = 2,5 kV<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Uma interpreta\u00e7\u00e3o comum \u00e9:<\/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\">\u201cSe este DPS operar, o inversor n\u00e3o ver\u00e1 mais do que 2,5 kV.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Isso \u00e9 simplista demais.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Para cima<\/strong> \u00e9 o n\u00edvel de prote\u00e7\u00e3o de tens\u00e3o do DPS determinado sob condi\u00e7\u00f5es de teste especificadas.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Uma vez que o DPS esteja instalado dentro de um sistema el\u00e9trico real, a tens\u00e3o desenvolvida atrav\u00e9s dos seus condutores de conex\u00e3o tamb\u00e9m deve ser considerada.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Uma forma simplificada de pensar sobre o n\u00edvel de prote\u00e7\u00e3o instalado \u00e9:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Tens\u00e3o efetiva no equipamento protegido \u2248 Up do DPS + contribui\u00e7\u00e3o de tens\u00e3o dos condutores de conex\u00e3o<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A Schneider Electric ilustra esta rela\u00e7\u00e3o usando a equa\u00e7\u00e3o de indut\u00e2ncia do condutor e descreve o n\u00edvel de prote\u00e7\u00e3o instalado como o Up do DPS mais a tens\u00e3o desenvolvida nas suas conex\u00f5es.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Isso n\u00e3o significa que voc\u00ea deva simplesmente adicionar um n\u00famero fixo a cada folha de dados de um DPS.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">O valor real depende de:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>comprimento do condutor,<\/li>\n\n\n\n<li>disposi\u00e7\u00e3o do condutor,<\/li>\n\n\n\n<li>\u00e1rea de la\u00e7o,<\/li>\n\n\n\n<li>corrente de surto,<\/li>\n\n\n\n<li>forma de onda de surto,<\/li>\n\n\n\n<li>arranjo de equipotencializa\u00e7\u00e3o,<\/li>\n\n\n\n<li>e o ponto no qual a tens\u00e3o est\u00e1 sendo avaliada.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A li\u00e7\u00e3o pr\u00e1tica \u00e9 muito mais simples:<\/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>Um bom DPS com uma instala\u00e7\u00e3o el\u00e9trica deficiente pode oferecer uma prote\u00e7\u00e3o instalada pior do que a sugerida apenas pela sua folha de dados.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Se voc\u00ea n\u00e3o estiver familiarizado com <strong>Ucpv, In, Imax, Up e Iscpv<\/strong>, consulte o nosso guia sobre <strong><a href=\"https:\/\/cnkuangya.com\/pt\/blog\/dc-spd-specifications\/\">como ler uma etiqueta de DPS CC<\/a><\/strong> antes de avaliar a coloca\u00e7\u00e3o do DPS.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">A dist\u00e2ncia do DPS ao inversor e o comprimento dos cabos do DPS n\u00e3o s\u00e3o a mesma coisa<\/h1>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Esta distin\u00e7\u00e3o \u00e9 fundamental porque <strong>a dist\u00e2ncia do DPS em rela\u00e7\u00e3o ao inversor<\/strong> is often confused with the length of the SPD&#8217;s own connecting conductors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As pessoas costumam dizer:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201cO DPS deve estar pr\u00f3ximo.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mas \u201cpr\u00f3ximo\u201d pode referir-se a duas dist\u00e2ncias completamente diferentes.<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">Dist\u00e2ncia 1: Arranjo Fotovoltaico \/ Localiza\u00e7\u00e3o do DPS at\u00e9 o Inversor<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Considere este arranjo:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Arranjo Fotovoltaico \u2192 Caixa de Jun\u00e7\u00e3o + DPS \u2192 30 m de Cabo CC \u2192 Inversor<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A quest\u00e3o aqui \u00e9 se a prote\u00e7\u00e3o fornecida em uma extremidade do cabo longo \u00e9 suficiente para o equipamento na outra extremidade.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Este \u00e9 um <strong>Problema de posicionamento e coordena\u00e7\u00e3o de DPS em n\u00edvel de sistema<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c9 aqui que a disposi\u00e7\u00e3o de 10 m da norma IEC 61643-32 se torna relevante.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Distance 2: The SPD&#8217;s Own Connecting Conductors<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Now imagine:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>DC Cable \u2192 SPD \u2192 PE \/ Bonding Point<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD may be installed physically beside the inverter, but its connecting wires may be long and looped around the enclosure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is a different problem.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 states for the DC-side arrangement in Clause 9.2.5 that the total length of the relevant connecting cables, shown as <strong>L1 + L2<\/strong>, should be as short as possible and preferably should not exceed <strong>0.5 m total lead length<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>10 m \u2260 0.5 m<\/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-distance-vs-connection-lead-length-1024x683.jpg\" alt=\"SPD distance from inverter versus SPD connection lead length\" class=\"wp-image-4417\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-distance-vs-connection-lead-length-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-distance-vs-connection-lead-length-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-distance-vs-connection-lead-length-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-distance-vs-connection-lead-length-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-distance-vs-connection-lead-length-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-distance-vs-connection-lead-length.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">The PV array-to-inverter distance and the SPD&#8217;s own connection lead length are two different engineering considerations.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The first concerns the distance between protected parts of the PV system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The second concerns the SPD&#8217;s own electrical connection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mixing these two numbers produces a lot of incorrect SPD advice online.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What Exactly Does IEC 61643-32 Say About 10 m?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">When engineers discuss <strong>a dist\u00e2ncia do DPS em rela\u00e7\u00e3o ao inversor<\/strong> in a PV system, the 10 m value is one of the most important distances to understand.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32:2017 Clause 9.2.5 addresses installation of SPDs on the DC side.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For PV installations described in <strong>6.2.1<\/strong> e <strong>6.2.2<\/strong>, it states that when distance <strong>E<\/strong> between the PV modules and inverter is equal to or greater than <strong>10 m<\/strong>, two sets of SPDs are necessary to sufficiently protect both the PV modules and inverter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the distance between the protected units is <strong>inferior a 10 m<\/strong>, one set of SPDs may be enough. The standard also notes that, for common PV modules, the inverter normally has the lower rated impulse withstand voltage, so installation of the SPD close to the inverter is recommended.<\/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\/iec-61643-32-10m-spd-distance-guide-1024x683.jpg\" alt=\"IEC 61643-32 10 m SPD distance from inverter illustration\" class=\"wp-image-4416\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/iec-61643-32-10m-spd-distance-guide-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/iec-61643-32-10m-spd-distance-guide-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/iec-61643-32-10m-spd-distance-guide-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/iec-61643-32-10m-spd-distance-guide-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/iec-61643-32-10m-spd-distance-guide-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/iec-61643-32-10m-spd-distance-guide.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">For relevant IEC 61643-32 PV configurations, the 10 m cable-route distance affects whether protection is required at both ends.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">This means that the often-mentioned \u201c10-meter rule\u201d is not simply an industry habit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It has a specific basis in IEC 61643-32.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, it should not be transformed into an oversimplified statement such as:<\/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 solar installation anywhere in the world automatically requires two SPDs once the cable reaches exactly 10 meters.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">That is also incorrect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 defines specific PV configurations, and national adoption, local installation standards, equipment instructions, risk assessment, and lightning protection conditions still have to be considered.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Which PV Installations Does the 10 m Requirement Apply To?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The context matters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 separates common PV installations into several arrangements.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">PV Installation Without an External Lightning Protection System<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This is the configuration described in Clause 6.2.1.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In general, IEC illustrates protection at both the inverter side and PV-array side, but it allows one of the DC SPDs to be omitted under specified conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, where the distance between inverter and PV array is less than 10 m and the voltage protection level of the remaining SPD is sufficiently coordinated with the PV array impulse withstand voltage, the additional SPD may not be necessary.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PV Installation With External LPS and Separation Distance Maintained<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Clause 6.2.2 addresses a building with an external lightning protection system where the required separation distance between the LPS and PV installation is maintained.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Again, IEC generally shows protection at both ends but permits omission under specified conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The DC-side 10 m principle in Clause 9.2.5 applies to this configuration as well.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PV Installation With External LPS and Separation Distance Not Maintained<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This is a more severe condition.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the required separation distance cannot be maintained, conductive PV components may become part of the lightning-current path.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 specifies Class I tested SPDs at the relevant locations for this configuration, and Clause 9.2.5 notes that the second SPD at the inverter is mandatory for the case described in 6.2.3.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the difference between Class I, Class II and the commonly used Type 1, Type 2 and Type 1+2 terminology is unclear, see our guide to <strong><a href=\"https:\/\/cnkuangya.com\/pt\/blog\/dc-spd-class-i-class-ii-and-class-iii-explained-a-practical-guide-to-pv-surge-protection\/\">DC SPD classes and types<\/a><\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Portanto:<\/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>Do not use distance alone to decide the SPD Type when an external lightning protection system is involved.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">The LPS design and separation distance must be evaluated first.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What Does \u201cOne Set of SPDs May Be Enough\u201d Really Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">This sentence is important.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC does <strong>n\u00e3o<\/strong> say:<\/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\">\u201cIf the PV cable is 9 meters long, one SPD is always enough.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">It says one set <strong>may be enough<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Por qu\u00ea?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because distance is only one factor.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD voltage protection level still has to be coordinated with the impulse withstand voltage of the equipment being protected.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC uses:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Uw<\/strong> = rated impulse withstand voltage of the equipment<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">e<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Para cima<\/strong> = voltage protection level of the SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For effective equipment protection, IEC 61643-32 states that Up must be lower than Uw and generally recommends maintaining at least a 20% safety margin:<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Up \u2264 0,8 \u00d7 Uw<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">subject to the applicable exceptions and coordination conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So a short cable does not excuse poor SPD selection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD still has to be electrically suitable for the equipment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a broader selection workflow covering voltage rating, Up, discharge-current ratings and installation conditions, see <strong><a href=\"https:\/\/cnkuangya.com\/pt\/blog\/how-to-size-a-dc-spd-for-a-solar-pv-array\/\">como dimensionar um DPS CC para um arranjo fotovoltaico solar<\/a><\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">A Simple PV Example<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Consider two systems using exactly the same Type 2 DC SPD.<\/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\/short-vs-long-spd-inverter-distance-1024x683.jpg\" alt=\"Short and long SPD distance from inverter comparison\" class=\"wp-image-4415\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/short-vs-long-spd-inverter-distance-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/short-vs-long-spd-inverter-distance-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/short-vs-long-spd-inverter-distance-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/short-vs-long-spd-inverter-distance-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/short-vs-long-spd-inverter-distance-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/short-vs-long-spd-inverter-distance.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">The same SPD may form part of a different protection arrangement when the PV cable route becomes much longer.<\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">System A<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 5 m DC Cable \u2192 SPD \u2192 Inverter<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD is close to the inverter.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">System B<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 SPD \u2192 30 m DC Cable \u2192 Inverter<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Both systems contain one SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But they should not automatically be treated as equivalent protection designs.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the relevant IEC configurations, System B crosses the 10 m distance described in Clause 9.2.5, meaning protection at both ends must be considered according to the standard requirement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The arrangement would typically become:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 SPD 1 \u2192 30 m DC Cable \u2192 SPD 2 \u2192 Inverter<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The exact SPD test class and ratings depend on the lightning protection condition and installation design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The important point is:<\/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>One SPD located somewhere on a long PV cable does not automatically provide sufficient coordinated protection at both ends.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What If the SPD Is Inside the PV Combiner Box?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">In this situation, <strong>a dist\u00e2ncia do DPS em rela\u00e7\u00e3o ao inversor<\/strong> becomes particularly important because the protection device may be located at one end of a long DC cable.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is one of the most common real-world situations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A commercial PV system may look like:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Cordas PV<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2193<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Caixa combinadora fotovoltaica<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>string fuses<\/li>\n\n\n\n<li>Isolador CC<\/li>\n\n\n\n<li>DC SPD<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u2193<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Long DC Cable<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2193<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Inversor<\/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\/pv-combiner-box-spd-30m-inverter-1024x683.jpg\" alt=\"PV combiner box SPD 30 m from solar inverter\" class=\"wp-image-4418\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/pv-combiner-box-spd-30m-inverter-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/pv-combiner-box-spd-30m-inverter-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/pv-combiner-box-spd-30m-inverter-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/pv-combiner-box-spd-30m-inverter-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/pv-combiner-box-spd-30m-inverter-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/pv-combiner-box-spd-30m-inverter.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">A combiner-box SPD may be only one protection location when a long DC cable separates the PV array and inverter.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">An installer opens the combiner box and sees a Type 2 SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The natural question is:<\/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\">\u201cWhy would I need another SPD? There is already one here.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">If the inverter is only a short distance away, the existing arrangement may satisfy the applicable protection requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But if the cable route between the PV generator and inverter reaches the distance defined by IEC 61643-32, protection at both ends becomes relevant.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Phoenix Contact&#8217;s current PV application guidance follows the same basic arrangement: it identifies DC surge protection near the PV panels and DC protection near the inverter and specifically uses <strong>10 m<\/strong> as the cable-distance criterion for the inverter-side location.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So the combiner-box SPD is not \u201cwrong.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It may simply represent only one protection location within a larger surge-protection concept.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What If the Inverter Already Has a Built-In SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Now the situation becomes more interesting.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Suppose the system is:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 External SPD \u2192 25 m DC Cable \u2192 Inverter with Built-In Type 2 SPD<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Potentially, you already have protection at both ends.<\/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\/built-in-inverter-spd-external-spd-layout-1024x683.jpg\" alt=\"Built-in inverter SPD and external DC SPD layout\" class=\"wp-image-4419\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/built-in-inverter-spd-external-spd-layout-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/built-in-inverter-spd-external-spd-layout-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/built-in-inverter-spd-external-spd-layout-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/built-in-inverter-spd-external-spd-layout-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/built-in-inverter-spd-external-spd-layout-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/built-in-inverter-spd-external-spd-layout.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">A built-in inverter SPD may form part of the inverter-side protection stage, but its actual specifications must be verified.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">But you cannot confirm that from the words:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u201cBuilt-in SPD\u201d<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">alone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You need to check what is actually inside the inverter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Important questions include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Is the built-in SPD on the DC side?<\/li>\n\n\n\n<li>Does it protect every relevant DC input or MPPT arrangement?<\/li>\n\n\n\n<li>Is it Type 2 or Type 1+2?<\/li>\n\n\n\n<li>What is its Ucpv?<\/li>\n\n\n\n<li>What is its Up?<\/li>\n\n\n\n<li>Is it replaceable?<\/li>\n\n\n\n<li>Does the inverter manufacturer count it as part of the required system surge protection?<\/li>\n\n\n\n<li>Are additional external SPDs specified in the installation manual?<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A built-in SPD may form part of the inverter-side protection stage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But:<\/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>Built-in SPD does not automatically mean complete PV-system surge protection.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">If this is the situation in your system, read <strong><a href=\"https:\/\/cnkuangya.com\/pt\/blog\/solar-inverter-built-in-spd\/\">My Solar Inverter Already Has an SPD \u2014 Do I Still Need an External SPD?<\/a><\/strong> for a detailed explanation of when built-in and external protection may need to work together.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why SPD location and inverter documentation must be considered together.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">SPD Distance From Inverter Checker<\/h1>\n\n\n\n<!-- KUANGYA SPD Distance From Inverter Checker -->\n<div class=\"kya-spd-tool\" id=\"kyaSpdDistanceTool\">\n\n  <div class=\"kya-tool-header\">\n    <span class=\"kya-tool-label\">PV SURGE PROTECTION TOOL<\/span>\n    <h2>SPD Distance From Inverter Checker<\/h2>\n    <p>\n      Use this SPD distance from inverter checker to make a preliminary assessment\n      of whether surge protection may be needed at both ends of a PV DC cable.\n    <\/p>\n  <\/div>\n\n  <div class=\"kya-tool-note\">\n    <strong>Importante:<\/strong>\n    This tool is intended as a preliminary engineering check. Final SPD selection\n    and placement must follow applicable standards, national requirements,\n    inverter manufacturer instructions, and the actual PV system design.\n  <\/div>\n\n  <div class=\"kya-form-grid\">\n\n    <div class=\"kya-field\">\n      <label for=\"kyaDistance\">\n        PV array to inverter cable-route distance\n      <\/label>\n\n      <div class=\"kya-input-unit\">\n        <input\n          type=\"number\"\n          id=\"kyaDistance\"\n          min=\"0\"\n          step=\"0.1\"\n          placeholder=\"e.g. 25\"\n        >\n        <span>m<\/span>\n      <\/div>\n\n      <small>\n        Enter the approximate cable-route length, not the straight-line distance.\n      <\/small>\n    <\/div>\n\n    <div class=\"kya-field\">\n      <label for=\"kyaLocation\">\n        Where is the existing DC SPD installed?\n      <\/label>\n\n      <select id=\"kyaLocation\">\n        <option value=\"\">Select an option<\/option>\n        <option value=\"array\">Near the PV array<\/option>\n        <option value=\"combiner\">Inside the combiner box<\/option>\n        <option value=\"inverter\">Near the inverter<\/option>\n        <option value=\"builtin\">Built into the inverter<\/option>\n        <option value=\"both\">SPDs at both ends<\/option>\n        <option value=\"none\">No SPD installed<\/option>\n        <option value=\"unknown\">Not sure<\/option>\n      <\/select>\n    <\/div>\n\n    <div class=\"kya-field\">\n      <label for=\"kyaBuiltin\">\n        Does the inverter include a built-in DC SPD?\n      <\/label>\n\n      <select id=\"kyaBuiltin\">\n        <option value=\"\">Select an option<\/option>\n        <option value=\"no\">N\u00e3o<\/option>\n        <option value=\"type2\">Yes \u2014 Type 2<\/option>\n        <option value=\"type12\">Yes \u2014 Type 1+2<\/option>\n        <option value=\"unknown-type\">Yes \u2014 type unknown<\/option>\n        <option value=\"unknown\">Not sure<\/option>\n      <\/select>\n    <\/div>\n\n    <div class=\"kya-field\">\n      <label for=\"kyaLps\">\n        Does the building have an external lightning protection system (LPS)?\n      <\/label>\n\n      <select id=\"kyaLps\">\n        <option value=\"\">Select an option<\/option>\n        <option value=\"no\">N\u00e3o<\/option>\n        <option value=\"maintained\">\n          Yes \u2014 separation distance maintained\n        <\/option>\n        <option value=\"not-maintained\">\n          Yes \u2014 separation distance not maintained\n        <\/option>\n        <option value=\"unknown\">Not sure<\/option>\n      <\/select>\n    <\/div>\n\n    <div class=\"kya-field kya-full\">\n      <label for=\"kyaLead\">\n        Are the SPD connecting conductors short and direct?\n      <\/label>\n\n      <select id=\"kyaLead\">\n        <option value=\"\">Select an option<\/option>\n        <option value=\"short\">\n          Yes \u2014 approximately \u2264 0.5 m total relevant lead length\n        <\/option>\n        <option value=\"long\">\n          No \u2014 longer than approximately 0.5 m\n        <\/option>\n        <option value=\"unknown\">\n          Not sure\n        <\/option>\n      <\/select>\n    <\/div>\n\n  <\/div>\n\n  <button type=\"button\" class=\"kya-check-btn\" onclick=\"kyaCheckSpdDistance()\">\n    Check My SPD Layout\n  <\/button>\n\n  <div class=\"kya-result\" id=\"kyaSpdResult\" aria-live=\"polite\"><\/div>\n\n<\/div>\n\n\n<style>\n.kya-spd-tool {\n  max-width: 900px;\n  margin: 36px auto;\n  padding: 32px;\n  border: 1px solid #e4e7eb;\n  border-radius: 16px;\n  background: #ffffff;\n  box-shadow: 0 8px 30px rgba(0,0,0,0.06);\n  font-family: Arial, Helvetica, sans-serif;\n}\n\n.kya-tool-header h2 {\n  margin: 8px 0 12px;\n  font-size: 28px;\n  line-height: 1.25;\n}\n\n.kya-tool-header p {\n  margin: 0;\n  color: #555;\n  line-height: 1.7;\n}\n\n.kya-tool-label {\n  display: inline-block;\n  font-size: 12px;\n  font-weight: 700;\n  letter-spacing: 1px;\n  padding: 6px 10px;\n  border-radius: 6px;\n  background: #f3f4f6;\n}\n\n.kya-tool-note {\n  margin: 24px 0;\n  padding: 16px 18px;\n  border-left: 4px solid #333;\n  background: #f7f7f7;\n  line-height: 1.6;\n}\n\n.kya-form-grid {\n  display: grid;\n  grid-template-columns: 1fr 1fr;\n  gap: 20px;\n}\n\n.kya-field {\n  display: flex;\n  flex-direction: column;\n}\n\n.kya-full {\n  grid-column: 1 \/ -1;\n}\n\n.kya-field label {\n  font-weight: 700;\n  margin-bottom: 8px;\n  line-height: 1.4;\n}\n\n.kya-field input,\n.kya-field select {\n  width: 100%;\n  box-sizing: border-box;\n  padding: 12px 13px;\n  border: 1px solid #ccd1d7;\n  border-radius: 8px;\n  background: #fff;\n  font-size: 15px;\n}\n\n.kya-field input:focus,\n.kya-field select:focus {\n  outline: none;\n  border-color: #555;\n}\n\n.kya-field small {\n  margin-top: 7px;\n  color: #777;\n  line-height: 1.45;\n}\n\n.kya-input-unit {\n  display: flex;\n  align-items: center;\n  border: 1px solid #ccd1d7;\n  border-radius: 8px;\n  overflow: hidden;\n}\n\n.kya-input-unit input {\n  border: 0;\n  border-radius: 0;\n}\n\n.kya-input-unit span {\n  padding: 0 15px;\n  font-weight: 700;\n  color: #555;\n  border-left: 1px solid #e1e4e8;\n}\n\n.kya-check-btn {\n  margin-top: 24px;\n  width: 100%;\n  padding: 14px 18px;\n  border: none;\n  border-radius: 8px;\n  background: #202124;\n  color: #fff;\n  font-size: 16px;\n  font-weight: 700;\n  cursor: pointer;\n}\n\n.kya-check-btn:hover {\n  opacity: 0.9;\n}\n\n.kya-result {\n  display: none;\n  margin-top: 24px;\n  padding: 22px;\n  border-radius: 12px;\n  line-height: 1.7;\n}\n\n.kya-result h3 {\n  margin-top: 0;\n  margin-bottom: 10px;\n  font-size: 22px;\n}\n\n.kya-result p {\n  margin: 8px 0;\n}\n\n.kya-result ul {\n  margin: 10px 0 0 20px;\n}\n\n.kya-result-good {\n  display: block;\n  background: #f4f8f4;\n  border: 1px solid #cfe1cf;\n}\n\n.kya-result-review {\n  display: block;\n  background: #fff9ed;\n  border: 1px solid #ead9ad;\n}\n\n.kya-result-alert {\n  display: block;\n  background: #fff3f3;\n  border: 1px solid #e4c2c2;\n}\n\n.kya-extra-warning {\n  margin-top: 16px;\n  padding: 13px 15px;\n  background: #fff;\n  border-left: 4px solid #777;\n}\n\n.kya-standard-note {\n  margin-top: 16px;\n  font-size: 13px;\n  color: #666;\n}\n\n@media (max-width: 700px) {\n  .kya-spd-tool {\n    padding: 22px 18px;\n  }\n\n  .kya-form-grid {\n    grid-template-columns: 1fr;\n  }\n\n  .kya-full {\n    grid-column: auto;\n  }\n\n  .kya-tool-header h2 {\n    font-size: 23px;\n  }\n}\n<\/style>\n\n\n<script>\nfunction kyaCheckSpdDistance() {\n\n  const distance = parseFloat(document.getElementById(\"kyaDistance\").value);\n  const location = document.getElementById(\"kyaLocation\").value;\n  const builtin = document.getElementById(\"kyaBuiltin\").value;\n  const lps = document.getElementById(\"kyaLps\").value;\n  const lead = document.getElementById(\"kyaLead\").value;\n\n  const result = document.getElementById(\"kyaSpdResult\");\n\n  result.className = \"kya-result\";\n  result.innerHTML = \"\";\n\n  if (\n    isNaN(distance) ||\n    distance < 0 ||\n    !location ||\n    !builtin ||\n    !lps ||\n    !lead\n  ) {\n    result.classList.add(\"kya-result-review\");\n    result.innerHTML = `\n      <h3>Please complete all fields<\/h3>\n      <p>\n        Enter the cable-route distance and select an option for each question\n        before running the preliminary check.\n      <\/p>\n    `;\n    return;\n  }\n\n  let output = \"\";\n  let resultClass = \"\";\n\n  \/* Highest-priority condition:\n     external LPS and separation distance not maintained *\/\n  if (lps === \"not-maintained\") {\n\n    resultClass = \"kya-result-alert\";\n\n    output = `\n      <h3>Lightning protection design requires additional evaluation<\/h3>\n\n      <p>\n        An external lightning protection system is present and the required\n        separation distance is not maintained.\n      <\/p>\n\n      <p>\n        In this condition, SPD selection should not be decided from cable\n        distance alone. The applicable IEC lightning-protection configuration,\n        lightning-current capability, equipotential bonding, and SPD test class\n        must be evaluated.\n      <\/p>\n\n      <p>\n        For the relevant IEC 61643-32 configuration, Class I tested protection\n        may be required at the specified locations.\n      <\/p>\n    `;\n\n  }\n\n  \/* No SPD *\/\n  else if (location === \"none\") {\n\n    resultClass = \"kya-result-alert\";\n\n    output = `\n      <h3>No DC SPD is currently identified<\/h3>\n\n      <p>\n        The system should be evaluated for DC surge protection before relying\n        on cable distance alone.\n      <\/p>\n\n      <p>\n        Check the PV installation standard, inverter manufacturer instructions,\n        lightning protection condition, equipment impulse withstand voltage,\n        and required SPD characteristics.\n      <\/p>\n    `;\n\n  }\n\n  \/* 10 m or more *\/\n  else if (distance >= 10) {\n\n    resultClass = \"kya-result-review\";\n\n    let builtInText = \"\";\n\n    if (builtin === \"type2\" || builtin === \"type12\") {\n      builtInText = `\n        <p>\n          Your inverter already reports a built-in DC SPD. This device may form\n          part of the inverter-side protection stage, but its Type, Ucpv, Up,\n          protected modes, and manufacturer instructions must be verified\n          before treating the two-end protection requirement as satisfied.\n        <\/p>\n      `;\n    }\n\n    if (location === \"both\") {\n      output = `\n        <h3>Two protection locations are already present<\/h3>\n\n        <p>\n          The PV array-to-inverter cable-route distance is\n          <strong>${distance.toFixed(1)} m<\/strong>.\n        <\/p>\n\n        <p>\n          For the relevant IEC 61643-32 PV configurations, a cable-route\n          distance of 10 m or more requires protection at both ends to\n          sufficiently protect the PV modules and inverter.\n        <\/p>\n\n        <p>\n          Your layout already indicates SPDs at both ends. The next step is to\n          verify SPD coordination, Ucpv, Up, discharge-current capability,\n          protected modes, grounding\/bonding, and manufacturer requirements.\n        <\/p>\n      `;\n    } else {\n      output = `\n        <h3>Protection at both ends should be checked<\/h3>\n\n        <p>\n          The PV array-to-inverter cable-route distance is\n          <strong>${distance.toFixed(1)} m<\/strong>.\n        <\/p>\n\n        <p>\n          For the relevant PV configurations covered by IEC 61643-32, when the\n          distance between PV modules and inverter is 10 m or more, two sets of\n          SPDs are necessary to sufficiently protect both ends.\n        <\/p>\n\n        ${builtInText}\n\n        <p>\n          Do not simply add another identical SPD without checking coordination,\n          SPD Type, Ucpv, Up, grounding, and the inverter manufacturer's\n          requirements.\n        <\/p>\n      `;\n    }\n\n  }\n\n  \/* Below 10 m *\/\n  else {\n\n    resultClass = \"kya-result-good\";\n\n    output = `\n      <h3>One SPD location may be sufficient<\/h3>\n\n      <p>\n        The PV array-to-inverter cable-route distance is\n        <strong>${distance.toFixed(1)} m<\/strong>, which is below 10 m.\n      <\/p>\n\n      <p>\n        For the relevant IEC 61643-32 configurations, one set of SPDs may be\n        sufficient when the applicable protection conditions are satisfied.\n      <\/p>\n\n      <p>\n        Distance alone is not enough to confirm the design. Check SPD voltage\n        protection level Up, equipment impulse withstand voltage Uw, Ucpv,\n        wiring arrangement, lightning protection condition, and manufacturer\n        instructions.\n      <\/p>\n    `;\n  }\n\n  \/* Additional lead-length warning *\/\n  if (lead === \"long\") {\n    output += `\n      <div class=\"kya-extra-warning\">\n        <strong>\u26a0 Check SPD connection lead length<\/strong>\n        <p>\n          The SPD connecting conductors are reported as longer than approximately\n          0.5 m total relevant lead length.\n        <\/p>\n        <p>\n          Long connecting conductors can add inductive voltage during a surge.\n          Review whether the connection can be made shorter, straighter, and\n          more direct.\n        <\/p>\n      <\/div>\n    `;\n  }\n\n  if (lead === \"unknown\") {\n    output += `\n      <div class=\"kya-extra-warning\">\n        <strong>Check the SPD wiring<\/strong>\n        <p>\n          The connection lead length is unknown. Inspect the actual SPD wiring\n          and keep the relevant conductors as short and direct as practical.\n        <\/p>\n      <\/div>\n    `;\n  }\n\n  if (lps === \"unknown\") {\n    output += `\n      <div class=\"kya-extra-warning\">\n        <strong>Lightning protection status is unknown<\/strong>\n        <p>\n          Confirm whether an external lightning protection system is present,\n          because this can change the required SPD test class and installation\n          arrangement.\n        <\/p>\n      <\/div>\n    `;\n  }\n\n  output += `\n    <div class=\"kya-standard-note\">\n      Preliminary guidance only. This checker does not replace IEC 61643-32,\n      applicable national installation rules, lightning protection design,\n      inverter instructions, or professional engineering assessment.\n    <\/div>\n  `;\n\n  result.classList.add(resultClass);\n  result.innerHTML = output;\n}\n<\/script>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why Must SPD Connecting Wires Be So Short?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Now return to the second distance problem.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Even if your SPD is installed at exactly the correct system location, its wiring can still reduce protection performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Considere:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Installation A<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>DC conductor \u2192 short connection \u2192 SPD \u2192 short PE connection<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">and:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Installation B<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>DC conductor \u2192 long loop \u2192 SPD \u2192 long loop \u2192 PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD model is identical.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its datasheet Up is identical.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Its Imax is identical.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But the installed protection can be different.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Phoenix Contact explains that excessive SPD connection length raises the effective voltage protection level because of voltage developed across the conductor inductance. Its installation guidance references the 0.5 m connection-length principle and shows how conductor voltage has to be added to the SPD protection level when evaluating the complete installed protection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 gives the same practical message for the DC side:<\/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\">keep the SPD connecting cables as short as possible.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">The 0.5 m figure should therefore be treated as a wiring target, not as a reason to mount an SPD exactly 500 mm from the inverter.<\/p>\n\n\n\n<!-- KUANGYA SPD Connection Lead Length Check -->\n<div class=\"kya-lead-tool\">\n\n  <h3>SPD Connection Lead Length Check<\/h3>\n\n  <p>\n    Enter the total relevant SPD connection lead length to check whether the\n    wiring should be reviewed.\n  <\/p>\n\n  <div class=\"kya-lead-row\">\n\n    <div class=\"kya-lead-input\">\n      <input\n        type=\"number\"\n        id=\"kyaLeadLength\"\n        min=\"0\"\n        step=\"1\"\n        placeholder=\"e.g. 40\"\n      >\n      <span>cm<\/span>\n    <\/div>\n\n    <button type=\"button\" onclick=\"kyaCheckLeadLength()\">\n      Check Lead Length\n    <\/button>\n\n  <\/div>\n\n  <div id=\"kyaLeadResult\" class=\"kya-lead-result\"><\/div>\n\n  <p class=\"kya-lead-disclaimer\">\n    This is a practical installation check, not a pass\/fail safety certification.\n    The applicable wiring arrangement, relevant standards, and manufacturer\n    instructions must also be considered.\n  <\/p>\n\n<\/div>\n\n<style>\n.kya-lead-tool {\n  margin: 30px 0;\n  padding: 26px;\n  border: 1px solid #e2e5e8;\n  border-radius: 14px;\n  background: #fafafa;\n  font-family: Arial, Helvetica, sans-serif;\n}\n\n.kya-lead-tool h3 {\n  margin-top: 0;\n  margin-bottom: 12px;\n  font-size: 22px;\n  line-height: 1.3;\n}\n\n.kya-lead-tool p {\n  line-height: 1.6;\n}\n\n.kya-lead-row {\n  display: flex;\n  gap: 12px;\n  margin-top: 18px;\n}\n\n.kya-lead-input {\n  flex: 1;\n  display: flex;\n  align-items: center;\n  border: 1px solid #ccd1d7;\n  border-radius: 8px;\n  background: #fff;\n  overflow: hidden;\n}\n\n.kya-lead-input input {\n  width: 100%;\n  border: 0;\n  padding: 12px;\n  font-size: 15px;\n  outline: none;\n  box-sizing: border-box;\n}\n\n.kya-lead-input span {\n  padding: 0 15px;\n  border-left: 1px solid #e1e4e8;\n  font-weight: 700;\n  color: #555;\n}\n\n.kya-lead-row button {\n  padding: 12px 20px;\n  border: 0;\n  border-radius: 8px;\n  background: #202124;\n  color: #fff;\n  font-weight: 700;\n  cursor: pointer;\n}\n\n.kya-lead-row button:hover {\n  opacity: 0.9;\n}\n\n.kya-lead-result {\n  display: none;\n  margin-top: 18px;\n  padding: 16px;\n  border-radius: 8px;\n  line-height: 1.6;\n}\n\n.kya-lead-good {\n  display: block;\n  background: #f4f8f4;\n  border: 1px solid #cfe1cf;\n}\n\n.kya-lead-review {\n  display: block;\n  background: #fff9ed;\n  border: 1px solid #ead9ad;\n}\n\n.kya-lead-disclaimer {\n  margin-bottom: 0;\n  margin-top: 16px;\n  font-size: 13px;\n  color: #777;\n}\n\n@media (max-width: 600px) {\n  .kya-lead-row {\n    flex-direction: column;\n  }\n\n  .kya-lead-row button {\n    width: 100%;\n  }\n}\n<\/style>\n\n<script>\nfunction kyaCheckLeadLength() {\n\n  const value = parseFloat(\n    document.getElementById(\"kyaLeadLength\").value\n  );\n\n  const result = document.getElementById(\"kyaLeadResult\");\n\n  result.className = \"kya-lead-result\";\n\n  if (isNaN(value) || value < 0) {\n    result.classList.add(\"kya-lead-review\");\n    result.innerHTML = `\n      <strong>Please enter a valid lead length.<\/strong>\n    `;\n    return;\n  }\n\n  if (value <= 50) {\n\n    result.classList.add(\"kya-lead-good\");\n\n    result.innerHTML = `\n      <strong>\u2713 Preferred practical range<\/strong><br>\n      The entered total lead length is ${value.toFixed(0)} cm.\n      This is within the approximately 0.5 m preferred total relevant\n      connection length referenced for the applicable IEC DC-side arrangement.\n      Keep the conductors short, direct, and free from unnecessary loops.\n    `;\n\n  } else {\n\n    result.classList.add(\"kya-lead-review\");\n\n    result.innerHTML = `\n      <strong>\u26a0 Review the connection layout<\/strong><br>\n      The entered total lead length is ${value.toFixed(0)} cm.\n      This exceeds approximately 0.5 m.\n      Consider whether the SPD connection path can be shortened or the wiring\n      arrangement improved to reduce inductive voltage contribution.\n    `;\n  }\n}\n<\/script>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\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-connection-lead-length-05m-1024x683.jpg\" alt=\"SPD connection lead length below and above 0.5 m\" class=\"wp-image-4420\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-05m-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-05m-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-05m-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-05m-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-05m-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-connection-lead-length-05m.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Keeping SPD connecting conductors short and direct helps reduce inductive voltage during a surge.<\/figcaption><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">An Engineering Example of Lead-Inductance Voltage<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Suppose we use a simplified conductor inductance of:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L \u2248 1 \u00b5H\/m<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">and a surge-current rise of:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>10 kA in 10 \u00b5s<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Then:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>di\/dt = 1 kA\/\u00b5s<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For one meter:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0394U = L \u00d7 di\/dt<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0394U \u2248 1 \u00b5H \u00d7 1 kA\/\u00b5s<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0394U \u2248 1 kV<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is the type of example Phoenix Contact uses to demonstrate why lead length matters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But this should <strong>n\u00e3o<\/strong> be turned into a calculator that claims:<\/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 meter always adds exactly 1 kV.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">It does not.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Real values change with:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>conductor spacing,<\/li>\n\n\n\n<li>conductor shape,<\/li>\n\n\n\n<li>routing,<\/li>\n\n\n\n<li>loop geometry,<\/li>\n\n\n\n<li>current waveform,<\/li>\n\n\n\n<li>current magnitude,<\/li>\n\n\n\n<li>and the actual surge-current path.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The calculation is best used to explain the physics, not to produce false precision.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Can I Solve the Distance Problem by Using a Higher-kA SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Suppose one SPD has:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Imax = 40 kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">and another:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Imax = 80 kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is tempting to think:<\/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\">\u201cIf my SPD is far from the inverter, I will simply install the 80 kA model.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">That does not solve the placement problem.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imax describes the maximum discharge-current capability under the specified 8\/20 \u00b5s test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It does not eliminate:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>long cable routes,<\/li>\n\n\n\n<li>conductor inductance,<\/li>\n\n\n\n<li>poor bonding,<\/li>\n\n\n\n<li>incorrect SPD location,<\/li>\n\n\n\n<li>excessive connecting-lead length,<\/li>\n\n\n\n<li>or lack of SPD coordination.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A higher Imax may be appropriate for some installations, but it is not a substitute for correct SPD placement.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Can a Lower Up Solve a Long-Distance Installation?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Again, not by itself.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A lower Up can improve equipment protection because it means the SPD limits voltage to a lower level under its specified test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But the final installed protection depends on the complete circuit.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Por exemplo:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">SPD A<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Up = 2.0 kV<br>Very long connecting conductors<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">SPD B<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Up = 2.5 kV<br>Very short, direct connections<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You cannot determine which installation produces the lower voltage at the equipment terminals from the SPD label alone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The conductor voltage contribution also matters.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is why SPD selection and SPD installation should never be treated as separate topics.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Does the Cable Route Matter, or Only the Cable Length?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The physical cable route matters too.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cable length is an easy number to measure, but electromagnetic behavior is influenced by geometry.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For surge currents, good practice includes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>keeping outgoing and return\/current-path conductors close together where appropriate,<\/li>\n\n\n\n<li>minimizing loop area,<\/li>\n\n\n\n<li>avoiding unnecessary conductor loops,<\/li>\n\n\n\n<li>using short bonding paths,<\/li>\n\n\n\n<li>and following the SPD manufacturer&#8217;s recommended connection arrangement.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 itself emphasizes minimizing loop areas in DC-side installation diagrams and recommends direct earthing between SPD and inverter for optimum overvoltage protection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So two systems with the same \u201c10 m cable length\u201d are not necessarily electromagnetically identical.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What Changes on the AC Side of the Inverter?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">An inverter is connected to more than one electrical system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It has a DC input from the PV array and an AC connection to the distribution system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 also addresses the AC side of the PV installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the AC side, it recommends that where the wiring between the SPD near the origin of the electrical installation and the inverter is <strong>10 m ou mais<\/strong>, the inverter should be protected by an additional SPD adjacent to the inverter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the more severe external-LPS configuration described in Clause 6.2.3, the additional SPD at the inverter is mandatory.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Phoenix Contact&#8217;s current selection guidance follows the same basic structure, showing an additional AC-side SPD near the inverter when the cable length to the main distribution is 10 m or more.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Portanto:<\/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>A DC SPD does not replace AC surge protection.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Both electrical interfaces need to be assessed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SPD placement is only one part of the overall protection architecture. For the relationship between SPDs, gPV fuses, DC isolators, combiner boxes and inverter protection, see our <strong><a href=\"https:\/\/cnkuangya.com\/pt\/blog\/solar-pv-electrical-protection\/\">complete solar PV electrical protection guide<\/a><\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Do Communication Cables Need Attention Too?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Modern PV inverters may also be connected to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>RS-485,<\/li>\n\n\n\n<li>Ethernet,<\/li>\n\n\n\n<li>energy meters,<\/li>\n\n\n\n<li>data loggers,<\/li>\n\n\n\n<li>sensors,<\/li>\n\n\n\n<li>remote monitoring systems,<\/li>\n\n\n\n<li>weather stations,<\/li>\n\n\n\n<li>or control equipment.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">These conductors can provide another path for transient overvoltages.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 states that when SPDs are required for the power circuits, surge protection should also be considered for telecommunications and signalling circuits associated with the PV system. Phoenix Contact makes the same practical recommendation for common inverter interfaces such as Ethernet and RS-485.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So an engineer reviewing inverter surge protection should ask:<\/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\">\u201cWhat conductors enter the inverter?\u201d<\/p>\n<\/blockquote>\n\n\n\n\n\n<p class=\"wp-block-paragraph\">not only:<\/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\">\u201cWhere is the DC SPD?\u201d<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What If the Building Has an External Lightning Protection System?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">This is where simplified internet advice becomes especially risky.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If a building has an <strong><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/33680\" rel=\"noopener\">external lightning protection system (LPS)<\/a><\/strong>, first determine whether the required separation distance <em>s<\/em> between the lightning protection system and the PV installation is maintained.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Separation Distance Maintained<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For the IEC configuration where the external LPS exists but separation distance is maintained, Class II tested PV SPDs are used at the relevant DC locations in the arrangement described by IEC 61643-32.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The 10 m DC-side placement principle still applies to the configuration covered by 6.2.2.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Separation Distance Not Maintained<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If separation distance cannot be maintained, parts of the PV system can carry partial lightning current.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This changes the required protection concept.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 specifies Class I tested SPDs at the relevant locations for this configuration, and the protection arrangement becomes more stringent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why you should never decide:<\/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\">\u201cType 2 is enough because the cable is only 8 meters.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">without first knowing the lightning protection condition.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Distance is only one part of the design.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Practical Installation Scenarios<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Scenario 1: Small Rooftop PV System<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 6 m DC Cable \u2192 Inverter<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">No external LPS.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A suitable SPD is installed close to the inverter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In this case, one set of DC SPDs may be sufficient if the applicable IEC conditions, Up coordination, equipment withstand voltage, and manufacturer instructions are satisfied.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The fact that the distance is below 10 m helps, but it is not the only requirement.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Scenario 2: Combiner Box 25 m From the Inverter<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 Combiner Box + SPD \u2192 25 m DC Cable \u2192 Inverter<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the relevant IEC 61643-32 configurations, the distance is \u226510 m.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Protection should therefore be provided at both ends in accordance with the standard arrangement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A second suitable SPD close to the inverter is required for the configurations addressed by Clause 9.2.5.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Scenario 3: Inverter Has Built-In Type 2 DC SPD<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 External SPD \u2192 25 m DC Cable \u2192 Built-In SPD \u2192 Inverter<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This may already resemble a two-location protection concept.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But the built-in device must be checked against:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>IEC classification,<\/li>\n\n\n\n<li>Ucpv,<\/li>\n\n\n\n<li>Up,<\/li>\n\n\n\n<li>protected poles\/modes,<\/li>\n\n\n\n<li>inverter topology,<\/li>\n\n\n\n<li>and manufacturer instructions.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Do not remove the external SPD simply because the inverter datasheet says \u201cSPD included.\u201d<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Scenario 4: SPD Beside the Inverter but With Long Leads<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PV Array \u2192 Inverter Cabinet<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Inside the cabinet:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>DC terminal \u2192 80 cm wire \u2192 SPD \u2192 70 cm PE wire<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The system-level location may be good.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD wiring is not.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The long connecting conductors can increase the installed protection level because of their inductive voltage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In this case, the first fix is not necessarily another SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It may be to redesign the connection.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Scenario 5: Building With External LPS and Separation Distance Not Maintained<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Now cable distance alone is no longer the main issue.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The system has to account for partial lightning current, lightning equipotential bonding, SPD test class, and the complete LPS design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This requires a lightning-protection-based SPD design rather than a simple \u201cless than or greater than 10 m\u201d decision.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Quick Engineering Decision Table<\/h1>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Situa\u00e7\u00e3o<\/th><th>What IEC-Based Design Tells You to Check<\/th><\/tr><\/thead><tbody><tr><td>PV array to inverter &lt;10 m<\/td><td>One set may be sufficient, subject to protection-level conditions<\/td><\/tr><tr><td>PV array to inverter \u226510 m<\/td><td>Two sets necessary for relevant IEC 61643-32 configurations<\/td><\/tr><tr><td>External LPS, separation maintained<\/td><td>Apply the relevant 6.2.2 SPD arrangement<\/td><\/tr><tr><td>External LPS, separation not maintained<\/td><td>More stringent Class I\/lightning-current protection applies<\/td><\/tr><tr><td>SPD leads approaching or exceeding 0.5 m<\/td><td>Review connection layout and installed protection level<\/td><\/tr><tr><td>SPD close to inverter<\/td><td>Still check Up, Ucpv, wiring, bonding and coordination<\/td><\/tr><tr><td>Inverter built-in SPD<\/td><td>Verify whether it satisfies the required inverter-side protection function<\/td><\/tr><tr><td>Long AC cable to main distribution<\/td><td>Additional AC-side SPD near inverter may be required\/recommended<\/td><\/tr><tr><td>Communication lines entering inverter<\/td><td>Evaluate surge protection for signalling\/data circuits<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Erros comuns<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 1: \u201cOne SPD Protects the Entire PV System\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">An SPD protects according to its location, installation, and coordination with the rest of the system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A device installed at one end of a long conductor should not automatically be assumed to provide the same protection at the other end.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 2: \u201c10 m Is Just a Recommendation From SPD Manufacturers\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The 10 m distinction appears directly in IEC 61643-32.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the relevant DC-side configurations, \u226510 m leads to a two-SPD requirement for sufficient protection of both PV modules and inverter.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 3: \u201c9.9 m Means One SPD Is Definitely Enough\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Also incorrect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Below 10 m, IEC says one set <strong>may<\/strong> be sufficient.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Protection-level coordination and the rest of the installation still matter.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 4: \u201c0.5 m Means the SPD Must Be Within 0.5 m of the Inverter\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The 0.5 m guidance refers to the SPD&#8217;s relevant connecting conductors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is not the same measurement as the PV-array-to-inverter distance.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 5: \u201cA Bigger kA Rating Fixes Poor Placement\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imax does not compensate for long conductors, poor bonding, or incorrect protection location.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 6: \u201cA Built-In SPD Means External SPDs Are Unnecessary\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not automatically.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Built-in protection has to be evaluated as part of the full PV protection concept.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 7: \u201cIf the DC Side Is Protected, the Inverter Is Protected\u201d<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The inverter also connects to AC and often to communication lines.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">All possible surge-entry paths should be reviewed.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Field Checklist Before Deciding Whether You Need Another SPD<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Before deciding that one SPD is enough, check:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">PV Layout<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>distance along the cable route between PV array and inverter;<\/li>\n\n\n\n<li>location of combiner boxes;<\/li>\n\n\n\n<li>location of existing SPDs;<\/li>\n\n\n\n<li>outdoor and indoor cable sections.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">DPS<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>IEC test class \/ SPD Type;<\/li>\n\n\n\n<li>Ucpv;<\/li>\n\n\n\n<li>Up;<\/li>\n\n\n\n<li>In;<\/li>\n\n\n\n<li>Imax or Iimp where applicable;<\/li>\n\n\n\n<li>Iscpv;<\/li>\n\n\n\n<li>protected modes;<\/li>\n\n\n\n<li>backup protection requirements.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Inversor<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>rated maximum DC voltage;<\/li>\n\n\n\n<li>rated impulse withstand voltage Uw, if available;<\/li>\n\n\n\n<li>built-in DC SPD;<\/li>\n\n\n\n<li>built-in AC SPD;<\/li>\n\n\n\n<li>manufacturer&#8217;s external SPD requirements.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Instala\u00e7\u00e3o<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SPD lead length;<\/li>\n\n\n\n<li>bonding conductor length;<\/li>\n\n\n\n<li>cable routing;<\/li>\n\n\n\n<li>loop area;<\/li>\n\n\n\n<li>PE routing;<\/li>\n\n\n\n<li>earthing arrangement.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Lightning Protection<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>external LPS present or absent;<\/li>\n\n\n\n<li>required separation distance;<\/li>\n\n\n\n<li>whether separation distance is maintained;<\/li>\n\n\n\n<li>lightning equipotential bonding requirements.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Only after these points are understood should the designer decide whether an additional SPD is unnecessary, recommended, or required.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">PERGUNTAS FREQUENTES<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Does the distance between the SPD and inverter really matter?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Sim.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The physical distance between protected parts of the PV system is specifically considered in IEC 61643-32, and long SPD connection leads can also increase the effective installed protection level.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These are two separate effects.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Do I need two DC SPDs when the PV array is 15 m from the inverter?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For PV installations covered by IEC 61643-32 Clauses 6.2.1 and 6.2.2, when the cable-route distance E between PV modules and inverter is equal to or greater than 10 m, Clause 9.2.5 requires two sets of SPDs to sufficiently protect both ends.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The exact SPD class and ratings still depend on the system and lightning protection arrangement.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">If the distance is only 8 m, is one SPD definitely enough?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC states that one set <strong>may be enough<\/strong> below 10 m.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD voltage protection level, equipment impulse withstand voltage, installation arrangement, and other conditions still need to be satisfied.<\/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 the single SPD be installed if the distance is less than 10 m?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IEC notes that common PV modules generally have a higher rated impulse withstand voltage than the inverter, and therefore recommends installing the SPD close to the inverter when one set is used.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is 10 m measured as straight-line distance?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For practical application, the relevant distance is the electrical cable-route distance between the units, not simply the straight-line distance measured through the air.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is 0.5 m the distance between the SPD and inverter?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the DC-side arrangement in IEC 61643-32 Clause 9.2.5, the 0.5 m recommendation refers to the total relevant SPD connecting leads, identified as L1 + L2 in the standard example.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Why does longer SPD wiring reduce protection?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Because the connecting conductors have inductance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">During a fast-rising surge current, the conductor develops an additional voltage:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u0394U = L \u00d7 di\/dt<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This additional voltage contributes to the installed voltage appearing at the protected equipment.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Can an inverter&#8217;s built-in SPD count as the inverter-side SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Potentially, yes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But its Type\/test class, Ucpv, Up, protected circuit arrangement, installation, and manufacturer requirements must first be verified.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Do not assume all built-in SPDs are equivalent.<\/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 DC SPD protect the inverter from AC-side surges?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e3o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">DC and AC are separate surge paths.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The AC-side protection arrangement must be evaluated separately.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What if my building has an external lightning protection system?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">First determine whether the required separation distance between the external LPS and PV installation is maintained.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If it is not maintained, IEC 61643-32 applies a more stringent lightning-current protection arrangement using Class I tested SPDs at the relevant locations.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Final Answer<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Yes. SPD distance from inverter matters in solar PV surge protection design.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But there are two different distances that must not be confused.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The first is:<\/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>the cable-route distance between the PV array and inverter.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">For the relevant IEC 61643-32 configurations:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>E &lt; 10 m<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2192 one set of SPDs may be sufficient if the required protection conditions are met.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>E \u2265 10 m<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2192 two sets of SPDs are necessary to sufficiently protect both PV modules and inverter.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The second distance is:<\/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>the length of the SPD&#8217;s own connecting conductors.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">These conductors should be kept as short as possible, with IEC 61643-32 giving a preferred total lead length of no more than approximately <strong>0.5 m<\/strong> for the DC-side arrangement shown in Clause 9.2.5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Neither rule should be used alone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A technically sound PV surge-protection design also considers:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Up, Uw, Ucpv, SPD test class, lightning protection system, separation distance, bonding, earthing, cable routing, inverter built-in protection, AC-side protection, and SPD coordination.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The useful question is therefore not:<\/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>\u201cHow many SPDs does my solar system have?\u201d<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c9:<\/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>\u201cAre the SPDs positioned, selected, and connected so that every vulnerable part of the system receives the required protection?\u201d<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">That is the difference between simply installing an SPD and designing a coordinated surge-protection system.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Need Help Reviewing Your PV SPD Layout?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If you are unsure whether the existing SPD is far enough from the inverter to require another protection stage, send us:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PV system voltage,<\/li>\n\n\n\n<li>inverter model,<\/li>\n\n\n\n<li>array-to-inverter cable distance,<\/li>\n\n\n\n<li>existing SPD location,<\/li>\n\n\n\n<li>SPD specifications,<\/li>\n\n\n\n<li>and a simple system layout.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">KUANGYA can help you identify the SPD parameters and installation positions that should be checked before product selection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You can also view our <strong><a href=\"https:\/\/cnkuangya.com\/pt\/dc-spd\/\">DC surge protective devices for solar PV systems<\/a><\/strong> for available Type 2 and Type 1+2 DC SPD options.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>KUANGYA \u2014 Surge Protection for Solar PV Systems<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>SPD distance from inverter is an important part of solar PV surge protection design, especially when the SPD is installed in a combiner box or near the PV array. You have installed a DC surge protective device in the PV system, but the SPD is inside the combiner box while the inverter is 20 or [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":4414,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-4413","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts\/4413","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/comments?post=4413"}],"version-history":[{"count":2,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts\/4413\/revisions"}],"predecessor-version":[{"id":4426,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts\/4413\/revisions\/4426"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/media\/4414"}],"wp:attachment":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/media?parent=4413"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/categories?post=4413"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/tags?post=4413"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}