{"id":4374,"date":"2026-08-29T13:57:07","date_gmt":"2026-08-29T05:57:07","guid":{"rendered":"https:\/\/cnkuangya.com\/?p=4374"},"modified":"2026-08-29T13:59:13","modified_gmt":"2026-08-29T05:59:13","slug":"dc-spd-specifications","status":"publish","type":"post","link":"https:\/\/cnkuangya.com\/it\/blog\/dc-spd-specifications\/","title":{"rendered":"Come leggere l'etichetta di un SPD DC: spiegazione di Classe II, Ucpv, In, Imax, Up e Iscpv"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Un dispositivo di protezione contro le sovratensioni (SPD) in corrente continua pu\u00f2 sembrare semplice all'esterno, ma le marcature stampate sulla sua etichetta contengono informazioni importanti su dove l'SPD pu\u00f2 essere utilizzato e sulle sue prestazioni.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Consideriamo questo esempio tratto da un SPD solare CC da 1000V:<\/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>Ucpv: 1000V CC<\/strong><br><strong>Classe II<\/strong><br><strong>In: 20kA<\/strong><br><strong>Imax: 40kA<\/strong><br><strong>Up: 4.0kV<\/strong><br><strong>Iscpv: 10kA<\/strong><br><strong>Da -40\u00b0C a +85\u00b0C<\/strong><br><strong>Interno, IP20<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Per un ingegnere elettrico esperto, queste abbreviazioni sono familiari.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Per un acquirente, un distributore, un installatore di impianti solari o un responsabile acquisti di progetto, tuttavia, possono facilmente creare confusione.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Significa <strong>Classe II<\/strong> un SPD di classe II?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c8 <strong>40kA Imax<\/strong> automaticamente migliore di 20kA?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Perch\u00e9 lo stesso SPD mostra entrambi <strong>1000V<\/strong> e <strong>4,0kV<\/strong>?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Significa <strong>Iscpv 10kA<\/strong> significa che l'SPD pu\u00f2 scaricare una sovratensione da fulmine di 10kA?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">La risposta breve \u00e8: <strong>nessun singolo numero descrive l'intero SPD.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un SPD DC dovrebbe essere letto come un insieme completo di caratteristiche elettriche. Se sei nuovo alla protezione contro le sovratensioni, prima comprendi <strong><a href=\"https:\/\/cnkuangya.com\/it\/blog\/what-is-dc-spd-solar-spd-pv-protection\/\">come funziona un SPD DC in un sistema solare fotovoltaico<\/a><\/strong> pu\u00f2 rendere queste specifiche pi\u00f9 facili da seguire.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Questa guida spiega come leggere correttamente tali marcature, utilizzando un <strong>SPD in CC di Classe II da 1000V<\/strong> come esempio pratico.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Risposta rapida: cosa significano le principali specifiche degli SPD in CC?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Prima di entrare nei dettagli tecnici, la tabella seguente fornisce una semplice panoramica.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Marcatura<\/th><th>Esempio<\/th><th>Significato semplice<\/th><\/tr><\/thead><tbody><tr><td>Ucpv<\/td><td>1000V CC<\/td><td>Tensione massima di esercizio continuativo per l'applicazione fotovoltaica<\/td><\/tr><tr><td>Classe II<\/td><td>Classe II<\/td><td>SPD testato in Classe II, associato alla protezione contro le sovratensioni di Tipo 2<\/td><\/tr><tr><td>In<\/td><td>20kA<\/td><td>Corrente nominale di scarica<\/td><\/tr><tr><td>Imax<\/td><td>40kA<\/td><td>Corrente massima di scarica<\/td><\/tr><tr><td>Su<\/td><td>4,0kV<\/td><td>Livello di protezione di tensione dichiarato<\/td><\/tr><tr><td>Iscpv<\/td><td>10kA<\/td><td>Corrente di cortocircuito FV nominale dell'SPD<\/td><\/tr><tr><td>Temperatura<\/td><td>Da -40\u00b0C a +85\u00b0C<\/td><td>Intervallo di temperatura operativa dichiarato<\/td><\/tr><tr><td>Umidit\u00e0<\/td><td>5%\u201395%<\/td><td>Intervallo di umidit\u00e0 dichiarato<\/td><\/tr><tr><td>Interno<\/td><td>Interno<\/td><td>Destinato a condizioni di installazione protette<\/td><\/tr><tr><td>IP20<\/td><td>IP20<\/td><td>Grado di protezione dell'involucro dell'SPD<\/td><\/tr><\/tbody><\/table><\/figure>\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\/08\/dc-spd-label-parameters-explained-1024x683.jpg\" alt=\"1000V DC SPD label showing Ucpv, Class II, In, Imax, Up and Iscpv specifications\" class=\"wp-image-4383\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-label-parameters-explained-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-label-parameters-explained-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-label-parameters-explained-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-label-parameters-explained-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-label-parameters-explained-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-label-parameters-explained.jpg 1535w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Un'etichetta di un SPD da 1000V DC contiene diverse specifiche, ognuna delle quali descrive una differente caratteristica elettrica.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Il punto pi\u00f9 importante \u00e8:<\/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>Non confrontare gli SPD DC basandosi solo sul valore kA pi\u00f9 alto stampato sull'etichetta.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Per esempio, <strong>Imax 40kA<\/strong>, <strong>In 20kA<\/strong> e <strong>Iscpv 10kA<\/strong> utilizzano tutti l'unit\u00e0 kA, ma descrivono caratteristiche completamente differenti.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Un ordine migliore per leggere l'etichetta di un SPD in corrente continua<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Quando gli acquirenti vedono per la prima volta una scheda tecnica di un SPD, spesso iniziano dal numero pi\u00f9 grande.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Di solito \u00e8 l'approccio sbagliato.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un ordine di lettura pi\u00f9 utile \u00e8:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Confermare che sia progettato per <strong>PV DC<\/strong><\/li>\n\n\n\n<li>Controllo <strong>Ucpv<\/strong><\/li>\n\n\n\n<li>Controllare il <strong>Tipo di SPD \/ Classe di prova<\/strong><\/li>\n\n\n\n<li>Controllo <strong>Su<\/strong><\/li>\n\n\n\n<li>Controllo <strong>In e Imax<\/strong><\/li>\n\n\n\n<li>Controllo <strong>Iscpv<\/strong><\/li>\n\n\n\n<li>Verificare il cablaggio e la configurazione di protezione<\/li>\n\n\n\n<li>Controllare le classificazioni ambientali<\/li>\n\n\n\n<li>Confermare lo standard e la documentazione di riferimento<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Questa procedura consente di scartare i prodotti non idonei prima di confrontare i valori nominali di corrente di scarica.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">VIOX utilizza un approccio simile di \u201cscarto preventivo delle specifiche incompatibili\u201d nella sua guida alle schede tecniche; per le applicazioni fotovoltaiche, questa logica diventa ancora pi\u00f9 importante poich\u00e9 Ucpv e il comportamento in cortocircuito del fotovoltaico richiedono un'attenzione specifica.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Cosa significa Classe II su un SPD per corrente continua (DC)?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Una delle prime indicazioni sull'etichetta di esempio \u00e8:<\/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>Classe II<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Questo non <strong>non<\/strong> significa qualit\u00e0 di seconda classe.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Classe I, Classe II e Classe III si riferiscono alle classificazioni di prova standardizzate degli SPD, non ai livelli di qualit\u00e0 del prodotto.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Per i dispositivi di protezione contro le sovratensioni (SPD) fotovoltaici, un SPD di Tipo 2 \u00e8 associato a <strong>Test di Classe II<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ecco perch\u00e9 diversi produttori o schede tecniche possono utilizzare diciture come:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tipo 2<\/li>\n\n\n\n<li>T2<\/li>\n\n\n\n<li>Classe II<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Si riferiscono a concetti di classificazione e test strettamente correlati, sebbene tecnicamente <strong>\u201cTipo\u201d e \u201cclasse di prova\u201d non sono semplicemente due grafie diverse dello stesso termine<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Per la maggior parte degli acquirenti, la relazione pratica pu\u00f2 essere intesa come segue:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Classificazione SPD<\/th><th>Classe di prova<\/th><th>Parametro di corrente principale<\/th><th>Forma d'onda di prova comune<\/th><\/tr><\/thead><tbody><tr><td>Tipo 1<\/td><td>Classe I<\/td><td>Iimp<\/td><td>10\/350 \u03bcs<\/td><\/tr><tr><td>Tipo 2<\/td><td>Classe II<\/td><td>In \/ Imax<\/td><td>8\/20 \u03bcs<\/td><\/tr><tr><td>Tipo 3<\/td><td>Classe III<\/td><td>Altri parametri di prova coordinati<\/td><td>Prova con onda combinata<\/td><\/tr><\/tbody><\/table><\/figure>\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\/08\/class-i-vs-class-ii-dc-spd-1024x683.jpg\" alt=\"Class I Type 1 vs Class II Type 2 DC SPD comparison\" class=\"wp-image-4384\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/class-i-vs-class-ii-dc-spd-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/class-i-vs-class-ii-dc-spd-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/class-i-vs-class-ii-dc-spd-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/class-i-vs-class-ii-dc-spd-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/class-i-vs-class-ii-dc-spd-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/class-i-vs-class-ii-dc-spd.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Le classi I e II descrivono diversi cicli di prova per SPD, non diversi livelli di qualit\u00e0 del prodotto.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Per l'esempio in questo articolo:<\/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>Classe II \u2192 direzione di applicazione Tipo 2<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">e pertanto i parametri di corrente pi\u00f9 importanti mostrati sono:<\/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 = 20kA<\/strong><br><strong>Imax = 40kA<\/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\">La Classe II \u00e8 peggiore della Classe I?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Questo \u00e8 uno dei malintesi pi\u00f9 comuni quando si confrontano gli SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I termini Classe I e Classe II possono sembrare una classificazione gerarchica:<\/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\">Classe I = migliore<br>Classe II = pi\u00f9 economico o meno potente<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Non \u00e8 cos\u00ec che funziona la classificazione degli SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Sono destinati a <strong>diverse condizioni di sovratensione<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un SPD di Tipo 1 \/ Classe I \u00e8 valutato per la capacit\u00e0 di corrente impulsiva da fulmine, laddove nel punto di installazione potrebbe essere necessario gestire correnti parziali di fulmine.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Un SPD di Tipo 2 \/ Classe II \u00e8 comunemente utilizzato per limitare le sovratensioni transitorie causate da effetti indotti dai fulmini e da manovre di commutazione.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pertanto, la domanda corretta non \u00e8:<\/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\">Quale classe \u00e8 migliore?<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u00c8:<\/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>Quale tipo di SPD \u00e8 richiesto in questo punto di installazione?<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Un SPD di Tipo 1 non \u00e8 automaticamente la scelta corretta per ogni impianto fotovoltaico, e un SPD di Tipo 2 non \u00e8 automaticamente inadeguato solo perch\u00e9 esiste il Tipo 1.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Se necessiti di una spiegazione dettagliata su questa questione di selezione, consulta la nostra guida:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><a href=\"https:\/\/cnkuangya.com\/it\/blog\/type-1-vs-type-2-spd-for-solar\/\">Type 1 vs Type 2 vs Type 1+2 DC SPD for Solar PV<\/a><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Your existing article goes deeper into lightning exposure, installation location and when Type 1 capability should be evaluated.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Class I vs Class II DC SPD: What Is the Real Difference?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The biggest technical difference becomes clearer when we look at the test current.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Class I \/ Type 1<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A Type 1 SPD is associated with an impulse-current rating:<\/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>Iimp<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">and a <strong>10\/350 \u03bcs<\/strong> current waveform is commonly associated with Class I testing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The 10\/350 \u03bcs waveform represents a much different current-energy duty than the 8\/20 \u03bcs waveform used for Type 2 evaluation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ci\u00f2 significa che:<\/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>Iimp cannot be directly compared with Imax just because both are shown in kA.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Ad esempio:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Iimp = 12.5kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">e<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Imax = 40kA<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">do not mean that the 40kA Type 2 product is \u201cstronger.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They refer to different test waveforms and different performance characteristics.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Class II \/ Type 2<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A Type 2 SPD is mainly characterized using:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In<\/li>\n\n\n\n<li>Imax<\/li>\n\n\n\n<li>Su<\/li>\n\n\n\n<li>Ucpv for PV applications<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The 8\/20 \u03bcs current waveform is associated with Class II discharge-current testing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Type 2 DC SPDs are commonly evaluated for use in locations such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Scatole combinatore FV<\/li>\n\n\n\n<li>Apparecchiature di distribuzione in corrente continua (DC)<\/li>\n\n\n\n<li>Ingressi CC dell'inverter<\/li>\n\n\n\n<li>other coordinated PV protection points<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">However, the final SPD type must still depend on the actual lightning protection design and installation conditions.<\/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\/08\/spd-10-350-vs-8-20-waveform-1024x683.jpg\" alt=\"10\/350 microsecond and 8\/20 microsecond SPD surge current waveform comparison\" class=\"wp-image-4385\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-10-350-vs-8-20-waveform-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-10-350-vs-8-20-waveform-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-10-350-vs-8-20-waveform-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-10-350-vs-8-20-waveform-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-10-350-vs-8-20-waveform-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-10-350-vs-8-20-waveform.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Iimp and Imax cannot be compared only by their kA values because they are associated with different test waveforms.<\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">What About Class III?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Class III exists within general SPD classification, but it should not become the main subject when discussing typical PV DC SPD selection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Class III protection is generally associated with coordinated fine protection close to sensitive equipment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For solar PV DC protection, buyers will much more commonly encounter:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Type 2 \/ Class II<\/li>\n\n\n\n<li>Tipo 1<\/li>\n\n\n\n<li>Tipo 1+2<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">That is why this article focuses mainly on <strong>Class II and its relationship with Type 2 DC SPDs<\/strong>, rather than treating Class I, II and III as three equally common PV product categories.<\/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 Ucpv 1000V DC Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The example label shows:<\/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>Ucpv: 1000V CC<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Ucpv means:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Maximum Continuous Operating Voltage for PV Application<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In simple terms:<\/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>Ucpv tells you the maximum DC voltage that may be continuously applied to the SPD&#8217;s mode of protection.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 defines Ucpv in essentially this way and states that it must be equal to or higher than the maximum PV open-circuit voltage condition relevant to the installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This makes Ucpv one of the first specifications that should be checked when selecting a solar DC SPD.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Does \u201c1000V System\u201d Automatically Mean You Need a 1000V SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Non necessariamente.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is important.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A PV system should not be evaluated using only a convenient nominal label 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\">1000V solar system<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">The actual maximum DC voltage of a PV string depends on factors including:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>module open-circuit voltage, Voc<\/li>\n\n\n\n<li>number of modules connected in series<\/li>\n\n\n\n<li>minimum design temperature<\/li>\n\n\n\n<li>module voltage temperature coefficient<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">PV module open-circuit voltage normally increases when temperature falls.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a broader explanation of PV array voltage, string design and related system requirements, see our <strong><a href=\"https:\/\/cnkuangya.com\/it\/blog\/iec-62548-explained\/\">IEC 62548 PV array design guide<\/a><\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, the selection process should be based on the <strong>maximum calculated PV open-circuit voltage<\/strong>, rather than simply copying the nominal inverter or system voltage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A simplified workflow is:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Module Voc<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2192 <strong>Number of modules in series<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2192 <strong>Low-temperature correction<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2192 <strong>Maximum PV open-circuit voltage<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u2192 <strong>Select suitable Ucpv<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We have already covered this subject separately in our <strong><a href=\"https:\/\/cnkuangya.com\/it\/blog\/dc-spd-selection-guide\/\">DC SPD Voltage Selection Guide<\/a><\/strong>, including 600V, 1000V and 1500V DC applications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So in this article, the important point is simply:<\/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>Ucpv is a continuous-voltage compatibility rating, not a surge-current rating.<\/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\">Ucpv Is Not the Same as Up<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">This is another common source of confusion.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Our example SPD shows:<\/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>Ucpv = 1000V DC<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">e<\/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>Up = 4.0kV<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">A buyer may reasonably 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\">Why does a 1000V SPD also have a 4kV voltage rating?<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Because these two values describe different things.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Parametro<\/th><th>Esempio<\/th><th>What It Describes<\/th><\/tr><\/thead><tbody><tr><td>Ucpv<\/td><td>1000V CC<\/td><td>Continuous PV operating voltage<\/td><\/tr><tr><td>Su<\/td><td>4,0kV<\/td><td>Voltage protection level during surge testing<\/td><\/tr><\/tbody><\/table><\/figure>\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\/08\/ucpv-vs-up-dc-spd-1024x683.jpg\" alt=\"Ucpv 1000V DC vs Up 4.0kV on a solar DC SPD\" class=\"wp-image-4387\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ucpv-vs-up-dc-spd-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ucpv-vs-up-dc-spd-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ucpv-vs-up-dc-spd-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ucpv-vs-up-dc-spd-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ucpv-vs-up-dc-spd-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ucpv-vs-up-dc-spd.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Ucpv describes continuous PV operating voltage, while Up describes the SPD&#8217;s declared voltage protection level.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">So:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ucpv is about surviving normal system operation.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Up is about limiting transient surge voltage.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They should never be treated as interchangeable voltage ratings.<\/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 In 20kA Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The label shows:<\/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: 20kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">In means:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Corrente di scarica nominale<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a Type 2 \/ Class II SPD, In is associated with an <strong>8\/20 \u03bcs current waveform<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In technical terms, it represents the crest value of the current through the SPD having the specified 8\/20 \u03bcs waveshape under the relevant standardized test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That definition is accurate, but for a buyer it can be simplified:<\/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 is one of the main ratings used to describe the tested surge-discharge performance of a Type 2 SPD.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">For this product:<\/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 = 20kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">The important word here is <strong>nominal<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It should not be confused with Imax.<\/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 Imax 40kA Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The same SPD also shows:<\/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>Imax: 40kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Imax means:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Corrente di scarica massima<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a Type 2 SPD, Imax is also normally associated with the <strong>8\/20 \u03bcs current waveform<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It represents the manufacturer&#8217;s declared maximum discharge-current capability under the applicable test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pertanto:<\/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 20kA and Imax 40kA are not duplicate specifications.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">They represent different test-duty levels.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">In 20kA vs Imax 40kA: What Is the Difference?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">This is one of the most important parts of the entire datasheet.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Consider the example:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Parametro<\/th><th>Valore<\/th><\/tr><\/thead><tbody><tr><td>In<\/td><td>20kA<\/td><\/tr><tr><td>Imax<\/td><td>40kA<\/td><\/tr><tr><td>Forma d'onda<\/td><td>8\/20 \u03bcs<\/td><\/tr><\/tbody><\/table><\/figure>\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\/08\/spd-in-vs-imax-explained-1024x683.jpg\" alt=\"SPD In 20kA vs Imax 40kA explained for a Type 2 DC SPD\" class=\"wp-image-4386\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-in-vs-imax-explained-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-in-vs-imax-explained-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-in-vs-imax-explained-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-in-vs-imax-explained-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-in-vs-imax-explained-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/spd-in-vs-imax-explained.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">In and Imax are both expressed in kA, but they represent different Type 2 SPD discharge-current ratings.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A simple way to understand them is:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In<\/strong> = nominal discharge-current rating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Imax<\/strong> = maximum declared discharge-current rating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One common purchasing mistake is to look only at Imax because it is the larger number.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ad esempio:<\/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\">SPD A: In 20kA \/ Imax 40kA<br>SPD B: In 10kA \/ Imax 40kA<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">A buyer may see \u201c40kA\u201d on both products and assume that their surge performance is equivalent.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That conclusion is incomplete.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The full declared performance needs to be checked.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">VIOX makes the same useful procurement distinction in its SPD datasheet guide: In and Imax should be read separately, and Imax should not be interpreted as the SPD&#8217;s normal repeated discharge capacity.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Does Higher Imax Always Mean a Better SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is probably the most useful purchasing rule in this article:<\/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 highest kA value does not automatically identify the best SPD.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Suppose two products are advertised as:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">SPD A<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ucpv: 1000V<\/li>\n\n\n\n<li>In: 20kA<\/li>\n\n\n\n<li>Imax: 40kA<\/li>\n\n\n\n<li>Up: 4.0kV<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">SPD B<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ucpv: 1000V<\/li>\n\n\n\n<li>In: 20kA<\/li>\n\n\n\n<li>Imax: 60kA<\/li>\n\n\n\n<li>Up: different<\/li>\n\n\n\n<li>short-circuit rating: unknown<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">It would be incorrect to select SPD B immediately just because:<\/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\">60kA &gt; 40kA.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Other questions still matter:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>What is its Type \/ Class?<\/li>\n\n\n\n<li>What is In?<\/li>\n\n\n\n<li>What is Up?<\/li>\n\n\n\n<li>What is Ucpv?<\/li>\n\n\n\n<li>What is Iscpv?<\/li>\n\n\n\n<li>What protection mode is declared?<\/li>\n\n\n\n<li>What backup protection is required?<\/li>\n\n\n\n<li>Is it specifically tested for PV DC use?<\/li>\n\n\n\n<li>Does its documentation match the project requirement?<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A larger number may be useful when the complete design calls for it.<\/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>More kA is not a substitute for correct coordination.<\/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\">Can a 40kA Type 2 SPD Replace a Type 1 SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Not simply because it says 40kA.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is another very common mistake.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A Type 2 product may show:<\/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>Imax = 40kA, 8\/20 \u03bcs<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">while a Type 1 product may show:<\/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>Iimp = 12.5kA, 10\/350 \u03bcs<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Looking only at the peak current numbers:<\/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\">40 &gt; 12.5<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">may make the Type 2 SPD appear stronger.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But that comparison is technically incorrect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The two values are based on different test waveforms and different protection duties.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pertanto:<\/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>Imax cannot be used as a substitute for a specified Iimp requirement.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">If the project requires Type 1 lightning-current capability, a large Type 2 Imax value alone does not satisfy that requirement.<\/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 Up 4.0kV Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The example label shows:<\/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>Up: 4.0kV<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Up means:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Livello di protezione della tensione<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It describes the SPD&#8217;s declared voltage-limiting performance under specified standardized test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In practical terms, Up helps answer the question:<\/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>How effectively does the SPD limit the transient voltage during the relevant test?<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Generally, a lower Up can provide a lower level of surge voltage at the SPD terminals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, this needs an important qualification.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The printed Up value should <strong>non<\/strong> be treated as the exact maximum voltage that every connected inverter or device will experience in a real installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Perch\u00e9?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because the actual voltage seen by the protected equipment can also be affected by:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SPD connection lead length<\/li>\n\n\n\n<li>conductor routing<\/li>\n\n\n\n<li>inductance<\/li>\n\n\n\n<li>installation arrangement<\/li>\n\n\n\n<li>earthing and bonding<\/li>\n\n\n\n<li>distance between the SPD and equipment<\/li>\n\n\n\n<li>coordination with other SPDs<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">VIOX correctly makes the same distinction: the declared Up is established at the SPD under standardized conditions, while installation conductors can increase the voltage presented to the protected equipment.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Is Lower Up Always Better?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Not by itself.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is reasonable to prefer effective voltage limitation, but the selection must remain compatible with the complete electrical system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A low Up does not compensate for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>insufficient Ucpv<\/li>\n\n\n\n<li>wrong SPD Type<\/li>\n\n\n\n<li>incorrect wiring<\/li>\n\n\n\n<li>poor earth connection<\/li>\n\n\n\n<li>unsuitable short-circuit characteristics<\/li>\n\n\n\n<li>excessively long leads<\/li>\n\n\n\n<li>incorrect coordination<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">So instead of saying:<\/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\">\u201cAlways buy the SPD with the lowest Up.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">A more technically correct rule 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>Select an SPD with a suitable Up while also verifying Ucpv, SPD Type, protected equipment withstand level and installation coordination.<\/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 Does Iscpv 10kA Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Now we come to one of the most misunderstood PV-specific parameters:<\/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>Iscpv: 10kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">This is particularly important because it also uses the unit <strong>kA<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is easy to look at:<\/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\">In 20kA<br>Imax 40kA<br>Iscpv 10kA<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">and assume they are three levels of surge current.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Non lo sono.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Iscpv means:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Short-Circuit Current Rating of the SPD for the PV application.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC terminology defines Iscpv as the maximum prospective short-circuit current from the power system for which the SPD, together with the specified disconnector, is rated.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A simpler explanation 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>Iscpv tells you whether the SPD and its specified disconnection arrangement are suitable for the prospective PV short-circuit current at the installation point.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">This is a <strong>fault-current \/ short-circuit characteristic<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is not a lightning-surge rating.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Iscpv 10kA Is Not the Same as Imax 10kA<\/h1>\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\/08\/iscpv-vs-imax-pv-spd-1024x683.jpg\" alt=\"Iscpv 10kA vs Imax 40kA photovoltaic DC SPD comparison\" class=\"wp-image-4388\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/iscpv-vs-imax-pv-spd-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/iscpv-vs-imax-pv-spd-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/iscpv-vs-imax-pv-spd-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/iscpv-vs-imax-pv-spd-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/iscpv-vs-imax-pv-spd-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/iscpv-vs-imax-pv-spd.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Iscpv is a PV short-circuit-current rating, while Imax describes surge discharge-current capability.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">This distinction deserves to be stated clearly:<\/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>Iscpv \u2260 Imax<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Even though both can be expressed in kA.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ad esempio:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Imax<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Describes surge discharge-current performance.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Iscpv<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Describes the SPD&#8217;s PV short-circuit-current rating in conjunction with the specified disconnection arrangement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So on our example product:<\/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>Imax = 40kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">does not mean:<\/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\">PV short-circuit rating = 40kA.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">And:<\/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>Iscpv = 10kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">does not mean:<\/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\">The SPD can only discharge a 10kA surge.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">These numbers belong to different electrical events.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why Is Iscpv Especially Important for PV DC Systems?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">PV DC circuits behave differently from ordinary AC circuits.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One important difference is that DC current does not naturally pass through zero every half-cycle as AC current does.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For protection devices, switching equipment and disconnecting arrangements, this makes DC fault interruption an important design consideration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is one reason PV-specific SPDs have characteristics and test requirements beyond simply printing:<\/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\">\u201cDC 1000V\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">on an AC-style product.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/26931\" rel=\"noopener\">IEC 61643-31<\/a> is specifically intended for SPDs connected to the DC side of photovoltaic installations and establishes PV-specific requirements, ratings and test methods.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, when buying a PV SPD, do not ask 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\">\u201cIs this 1000V DC?\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Also 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\"><strong>What is the declared Iscpv and required disconnection arrangement?<\/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\">In, Imax, Iimp and Iscpv: Do Not Mix Them Up<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The easiest way to remember these parameters is with this table:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Valutazione<\/th><th>Main Meaning<\/th><th>Typical Context<\/th><\/tr><\/thead><tbody><tr><td>In<\/td><td>Corrente nominale di scarica<\/td><td>Type 2 \/ Class II surge performance<\/td><\/tr><tr><td>Imax<\/td><td>Corrente massima di scarica<\/td><td>Type 2 maximum declared surge-current performance<\/td><\/tr><tr><td>Iimp<\/td><td>Impulse current<\/td><td>Type 1 \/ Class I lightning-current capability<\/td><\/tr><tr><td>Iscpv<\/td><td>PV short-circuit current rating<\/td><td>PV fault-current compatibility<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Notice something important:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Three or four specifications can all contain:<\/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>kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">but this does not mean they can be compared directly.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before comparing any two kA ratings, first ask:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>What parameter is this?<\/li>\n\n\n\n<li>What waveform is used?<\/li>\n\n\n\n<li>What SPD Type is involved?<\/li>\n\n\n\n<li>Is this a surge test or a short-circuit rating?<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">This prevents a large number of purchasing errors.<\/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 \u201c-40\u00b0C to +85\u00b0C\u201d Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The label also declares:<\/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>Da -40\u00b0C a +85\u00b0C<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">This is the manufacturer&#8217;s declared temperature range for the product.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Environmental ratings should not be ignored simply because electrical parameters look correct.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">PV equipment may be installed in:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>rooftop combiner boxes<\/li>\n\n\n\n<li>inverter cabinets<\/li>\n\n\n\n<li>outdoor electrical enclosures<\/li>\n\n\n\n<li>industrial PV rooms<\/li>\n\n\n\n<li>high-temperature regions<\/li>\n\n\n\n<li>cold-weather installations<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The internal temperature of an enclosure can be very different from the normal outdoor air temperature.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, project engineers should confirm that the SPD&#8217;s declared environmental conditions are suitable for the actual enclosure and installation environment.<\/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 5%\u201395% Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Where the datasheet declares:<\/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>5%\u201395%<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">this normally represents the manufacturer&#8217;s declared relative humidity operating range.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, humidity specifications should always be read together with conditions such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>condensation requirements<\/li>\n\n\n\n<li>enclosure protection<\/li>\n\n\n\n<li>posizione di installazione<\/li>\n\n\n\n<li>temperature<\/li>\n\n\n\n<li>pollution conditions<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The percentage alone does not mean that an exposed SPD can be installed directly in rain or other outdoor environments.<\/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 Indoor Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The label states:<\/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>Interno<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">This does not necessarily mean that the SPD can never form part of an outdoor PV installation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It means the SPD itself is intended for a protected environment according to its declared construction and installation conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, an indoor-rated SPD may be installed inside:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>a suitable outdoor PV combiner box<\/li>\n\n\n\n<li>an IP-rated enclosure<\/li>\n\n\n\n<li>an inverter cabinet<\/li>\n\n\n\n<li>a protected electrical cabinet<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The important distinction 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 SPD can be inside outdoor equipment without the SPD itself being directly exposed to outdoor conditions.<\/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 Does IP20 Mean?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">IP20 is the enclosure protection rating shown for the SPD itself.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It should not be interpreted as a weatherproof rating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A DIN-rail SPD with IP20 is normally installed inside another suitable enclosure or cabinet.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For an outdoor PV installation, the final environmental protection depends on the <strong>complete enclosure<\/strong>, not only the bare SPD module.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So:<\/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>IP20 SPD inside a suitable outdoor enclosure<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">can be a normal arrangement.<\/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>IP20 SPD directly exposed to rain, dust and outdoor weather<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">should not be assumed to be acceptable.<\/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\/08\/ip20-dc-spd-outdoor-enclosure-1024x683.jpg\" alt=\"IP20 DC SPD installed inside an outdoor photovoltaic enclosure\" class=\"wp-image-4389\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ip20-dc-spd-outdoor-enclosure-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ip20-dc-spd-outdoor-enclosure-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ip20-dc-spd-outdoor-enclosure-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ip20-dc-spd-outdoor-enclosure-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ip20-dc-spd-outdoor-enclosure-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/ip20-dc-spd-outdoor-enclosure.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">An IP20 SPD can be used inside a suitable protected enclosure but should not be directly exposed to outdoor weather.<\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">How Should You Read This 1000V DC SPD Label as a Whole?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Now we can return to the original example.<\/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>Ucpv: 1000V CC<\/strong><br><strong>Classe II<\/strong><br><strong>In: 20kA<\/strong><br><strong>Imax: 40kA<\/strong><br><strong>Up: 4.0kV<\/strong><br><strong>Iscpv: 10kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Instead of reading each number independently, read it as one technical description.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Ucpv 1000V DC<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This tells us the declared maximum continuous PV operating voltage of the SPD.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Classe II<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This indicates Class II testing \/ Type 2 application direction.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">In 20kA<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This is the nominal discharge-current rating associated with the relevant Type 2 surge test.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Imax 40kA<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This is the declared maximum discharge-current rating.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Up 4.0kV<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This is the declared voltage protection level.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Iscpv 10kA<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">This is the PV short-circuit-current rating and must be understood together with the applicable disconnector\/protection arrangement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Now the label makes much more sense.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is not saying:<\/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\">\u201c1000V, 20kA, 40kA, 10kA \u2014 bigger numbers are better.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">It is describing <strong>different electrical functions and limits<\/strong> of the same SPD.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">6 Common Mistakes When Reading a DC SPD Datasheet<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">1. Treating Class II as a Quality Grade<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect:<\/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\">Class I is premium and Class II is lower quality.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Correct:<\/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\">Class I and Class II represent different test\/protection classifications.<\/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\">2. Selecting an SPD Only by Imax<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect:<\/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\">This one says 60kA, so it is automatically better than the 40kA model.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Correct:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tipo<\/li>\n\n\n\n<li>Ucpv<\/li>\n\n\n\n<li>In<\/li>\n\n\n\n<li>Imax<\/li>\n\n\n\n<li>Su<\/li>\n\n\n\n<li>Iscpv<\/li>\n\n\n\n<li>standard<\/li>\n\n\n\n<li>wiring and protection requirements<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">before making the comparison.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">3. Comparing Iimp Directly with Imax<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect:<\/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\">Imax 40kA is higher than Iimp 12.5kA, so Type 2 is stronger.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Correct:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Iimp and Imax refer to different test waveforms and different surge duties.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">4. Confusing Ucpv with Up<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect:<\/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\">The SPD is rated 1000V but Up is 4kV, so the specifications conflict.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Correct:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ucpv and Up describe different voltage characteristics.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">5. Treating Iscpv as a Surge Rating<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Incorrect:<\/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\">Iscpv 10kA means the SPD can discharge 10kA of lightning current.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Correct:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Iscpv is a PV short-circuit-current rating.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">6. Ignoring Installation Conditions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Even a correctly selected SPD can provide poor protection if installation is poor.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Important details include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>lunghezza del cavo<\/li>\n\n\n\n<li>conductor routing<\/li>\n\n\n\n<li>Collegamento PE<\/li>\n\n\n\n<li>enclosure<\/li>\n\n\n\n<li>coordination<\/li>\n\n\n\n<li>backup protection<\/li>\n\n\n\n<li>distance from protected equipment<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A datasheet tells you what the device is capable of under defined conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Installation determines how effectively that capability is used in the real system.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD should also be considered together with other <strong><a href=\"https:\/\/cnkuangya.com\/it\/blog\/solar-pv-electrical-protection\/\">solar PV electrical protection<\/a><\/strong> devices, including DC fuses, isolators, circuit breakers and the overall protection arrangement.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">How to Check a DC SPD Before Buying<\/h1>\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\/08\/dc-spd-selection-checklist-1024x683.jpg\" alt=\"DC SPD specifications selection checklist for solar PV systems\" class=\"wp-image-4390\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-selection-checklist-1024x683.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-selection-checklist-300x200.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-selection-checklist-768x512.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-selection-checklist-18x12.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-selection-checklist-600x400.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/08\/dc-spd-selection-checklist.jpg 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">A practical sequence for checking DC SPD specifications before purchasing or approving a product.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">For buyers, distributors and EPC procurement teams, the following sequence is more useful than simply asking for:<\/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\">\u201c1000V 40kA SPD price.\u201d<\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">Step 1 \u2014 Confirm the Application<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Is the product specifically intended for:<\/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>PV DC surge protection?<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Do not assume an AC SPD with a similar voltage or current marking is interchangeable.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 2 \u2014 Check Maximum PV Voltage<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Determine the maximum possible PV open-circuit voltage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Then confirm that the selected Ucpv is suitable.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the full calculation method, refer to the DC SPD Voltage Selection Guide mentioned earlier.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Step 3 \u2014 Confirm Type \/ Class<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Determine whether the installation requires:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Tipo 2<\/li>\n\n\n\n<li>Tipo 1<\/li>\n\n\n\n<li>Tipo 1+2<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Do not make this decision simply from product price or kA rating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Our detailed <strong>Type 1 vs Type 2 vs Type 1+2 DC SPD<\/strong> guide explains this separately.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 4 \u2014 Check In and Imax<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For a Type 2 \/ Class II SPD, confirm both values.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Do not check only Imax.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 5 \u2014 Check Up<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Verify the declared voltage protection level and whether it is appropriate for the protected equipment and 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\">Step 6 \u2014 Check Iscpv<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Confirm that the SPD and specified disconnection\/protection arrangement are compatible with the prospective short-circuit current of the PV system.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 7 \u2014 Check Installation Configuration<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Confirm:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>pole configuration<\/li>\n\n\n\n<li>DC+\/DC\u2212 arrangement<\/li>\n\n\n\n<li>Collegamento PE<\/li>\n\n\n\n<li>protection mode<\/li>\n\n\n\n<li>backup protection<\/li>\n\n\n\n<li>Schema di cablaggio<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 8 \u2014 Check Environmental Conditions<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Verificate:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>temperature range<\/li>\n\n\n\n<li>umidit\u00e0<\/li>\n\n\n\n<li>indoor\/outdoor condition<\/li>\n\n\n\n<li>enclosure IP rating<\/li>\n\n\n\n<li>installation altitude where relevant<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Step 9 \u2014 Verify the Standard and Documentation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">For PV DC SPDs, IEC 61643-31 is an important product standard to check.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-31:2018 covers SPDs intended for the DC side of photovoltaic installations up to 1500V DC, while IEC 61643-32:2017 addresses their selection, installation and coordination.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Depending on the project and market, buyers may also need:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>certificato<\/li>\n\n\n\n<li>test report<\/li>\n\n\n\n<li>datasheet<\/li>\n\n\n\n<li>Schema di cablaggio<\/li>\n\n\n\n<li>dimensional drawing<\/li>\n\n\n\n<li>declaration of conformity<\/li>\n\n\n\n<li>project-specific approvals<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Do not assume that a logo printed on a product is sufficient evidence.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Match the documentation to the exact model being purchased.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">DC SPD Specification Checklist<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Before approving a PV SPD, use the following checklist.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Controllo<\/th><th>Domanda<\/th><\/tr><\/thead><tbody><tr><td>Applicazione<\/td><td>Is it specifically suitable for PV DC?<\/td><\/tr><tr><td>Ucpv<\/td><td>Is it suitable for maximum PV open-circuit voltage?<\/td><\/tr><tr><td>Tipo SPD<\/td><td>Does Type 1 \/ Type 2 \/ Type 1+2 match the installation design?<\/td><\/tr><tr><td>Classe di prova<\/td><td>Is the declared classification clear?<\/td><\/tr><tr><td>In<\/td><td>Is the nominal discharge-current rating specified?<\/td><\/tr><tr><td>Imax<\/td><td>Is the maximum discharge-current rating specified?<\/td><\/tr><tr><td>Iimp<\/td><td>If Type 1 is required, is Iimp declared?<\/td><\/tr><tr><td>Su<\/td><td>Is the protection level suitable?<\/td><\/tr><tr><td>Iscpv<\/td><td>Is the PV short-circuit rating adequate?<\/td><\/tr><tr><td>Cablaggio<\/td><td>Is the correct DC connection diagram available?<\/td><\/tr><tr><td>Protezione<\/td><td>Is required backup protection identified?<\/td><\/tr><tr><td>Ambiente<\/td><td>Are temperature, IP and enclosure conditions suitable?<\/td><\/tr><tr><td>Standard<\/td><td>Is the applicable PV SPD standard stated?<\/td><\/tr><tr><td>Documentazione<\/td><td>Do certificates\/test reports match the exact model?<\/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\">Example: How a Buyer Should Request a 1000V DC SPD<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">A weak RFQ might 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\">Please quote 1000V 40kA solar SPD.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">This leaves many important questions unanswered.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A better RFQ 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\">Please quote a Type 2 \/ Class II PV DC SPD for a 1000V DC application. Please confirm Ucpv, In, Imax, Up, Iscpv, pole configuration, required backup protection, IEC 61643-31 documentation and wiring diagram.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">If known, also include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>actual maximum string Voc<\/li>\n\n\n\n<li>quantit\u00e0<\/li>\n\n\n\n<li>installation point<\/li>\n\n\n\n<li>system configuration<\/li>\n\n\n\n<li>minimum temperature<\/li>\n\n\n\n<li>enclosure\/application<\/li>\n\n\n\n<li>OEM requirements<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This allows the manufacturer to evaluate the complete requirement instead of matching only the words:<\/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\">\u201c1000V\u201d and \u201c40kA.\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\">Domande frequenti<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Is Class II the Same as Type 2 SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">They are closely related but technically describe classification\/testing from slightly different perspectives.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For practical PV product selection, a Type 2 SPD is associated with <strong>Test di Classe II<\/strong>, which is why labels and datasheets may show Type 2, T2 or Class II terminology.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is Class II SPD Lower Quality Than Class I?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Class I and Class II are not quality levels.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They are intended for different surge-protection duties and test conditions.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What Is the Difference Between In and Imax?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In is the <strong>nominal discharge current<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imax is the <strong>maximum discharge current<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For Type 2 SPDs, both are normally associated with the 8\/20 \u03bcs waveform, but they represent different test-duty levels.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is 40kA Imax Better Than 20kA?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not enough information is available to answer that from Imax alone.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A proper comparison also requires Ucpv, Type, In, Up, Iscpv, standard, protection configuration and installation conditions.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Can a 40kA Type 2 SPD Replace a Type 1 SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not simply because its peak current number is larger.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Type 1 is characterized by lightning impulse-current capability such as Iimp and the associated Class I test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imax and Iimp should not be directly compared.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What Is the Difference Between Ucpv and Up?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Ucpv<\/strong> is the maximum continuous operating voltage for the PV application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Su<\/strong> is the declared voltage protection level under specified surge test conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They perform completely different functions in the datasheet.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What Does Iscpv Mean?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Iscpv is the short-circuit current rating of the PV SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">More precisely, it describes the maximum prospective short-circuit current for which the SPD, together with its specified disconnector arrangement, is rated.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is Iscpv the Same as Imax?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">No.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Imax is a surge discharge-current rating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Iscpv is a short-circuit-current rating.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The fact that both use kA does not make them interchangeable.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is a 1000V DC SPD Suitable for Every 1000V Solar System?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not automatically.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Maximum PV open-circuit voltage should be calculated under the project&#8217;s design conditions before selecting Ucpv.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For more detail, see our <strong>Guida alla selezione degli SPD DC: come scegliere la tensione nominale corretta<\/strong>.<\/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 IP20 SPD Be Used in an Outdoor Solar Installation?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">It may be installed <strong>inside a suitable outdoor enclosure<\/strong>, provided the complete installation satisfies the required environmental protection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IP20 on the SPD itself should not be treated as a weatherproof outdoor rating.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What Standard Should Be Checked for a PV DC SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-31 covers requirements and test methods for SPDs intended for the DC side of photovoltaic installations up to 1500V DC.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">IEC 61643-32 provides selection and application principles for PV SPDs.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Conclusione<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Reading a DC SPD datasheet becomes much easier once each parameter is treated according to its actual purpose.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For the example:<\/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>Classe II<\/strong><br><strong>Ucpv 1000V DC<\/strong><br><strong>In 20kA<\/strong><br><strong>Imax 40kA<\/strong><br><strong>Up 4.0kV<\/strong><br><strong>Iscpv 10kA<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">the correct interpretation is not simply:<\/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\">\u201cThis is a 1000V, 40kA SPD.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">A more complete interpretation is:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Classe II<\/strong> identifies its Class II \/ Type 2 protection direction.<\/li>\n\n\n\n<li><strong>Ucpv 1000V DC<\/strong> describes continuous PV voltage compatibility.<\/li>\n\n\n\n<li><strong>In 20kA<\/strong> describes nominal discharge-current performance.<\/li>\n\n\n\n<li><strong>Imax 40kA<\/strong> describes maximum declared discharge-current performance.<\/li>\n\n\n\n<li><strong>Up 4.0kV<\/strong> describes the declared voltage protection level.<\/li>\n\n\n\n<li><strong>Iscpv 10kA<\/strong> describes the PV short-circuit-current rating.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Each specification answers a different engineering question.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That leads to one simple purchasing principle:<\/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>Never select a DC SPD from one voltage number, one kA number or one Type label alone.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">The correct SPD is the one whose complete set of ratings matches the PV system voltage, surge environment, equipment protection requirements, short-circuit conditions and installation design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For solar PV projects requiring 600V, 1000V or 1500V surge protection, explore <strong><a href=\"https:\/\/cnkuangya.com\/it\/dc-spd\/\">KUANGYA DC surge protective devices<\/a><\/strong> to compare available Type 2 and Type 1+2 models by voltage rating, discharge-current capability and application. <\/p>","protected":false},"excerpt":{"rendered":"<p>A DC surge protective device may look simple from the outside, but the markings printed on its label contain important information about where the SPD can be used and how it performs. Consider this example from a 1000V DC solar SPD: Ucpv: 1000V DCClass IIIn: 20kAImax: 40kAUp: 4.0kVIscpv: 10kA-40\u00b0C to +85\u00b0CIndoor, IP20 For an experienced [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":4381,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-4374","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/posts\/4374","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/comments?post=4374"}],"version-history":[{"count":2,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/posts\/4374\/revisions"}],"predecessor-version":[{"id":4393,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/posts\/4374\/revisions\/4393"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/media\/4381"}],"wp:attachment":[{"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/media?parent=4374"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/categories?post=4374"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnkuangya.com\/it\/wp-json\/wp\/v2\/tags?post=4374"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}