{"id":2112,"date":"2025-06-17T16:28:06","date_gmt":"2025-06-17T08:28:06","guid":{"rendered":"https:\/\/www.britecelectric.com\/?post_type=blog&#038;p=2112"},"modified":"2025-08-19T16:03:23","modified_gmt":"2025-08-19T08:03:23","slug":"ac-vs-dc-surge-protection-whats-the-difference","status":"publish","type":"blog","link":"https:\/\/www.britecelectric.com\/it\/blog\/ac-vs-dc-surge-protection-whats-the-difference\/","title":{"rendered":"AC vs. DC Surge Protection: What&#8217;s the Difference?"},"content":{"rendered":"La protezione contro le sovratensioni \u00e8 fondamentale per la sicurezza e l'operativit\u00e0 dei moderni sistemi elettrici. Scegliere il giusto <a href=\"https:\/\/www.britecelectric.com\/it\/products\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"1300\" data-end=\"1333\">Dispositivo di protezione contro le sovratensioni (SPD)<\/strong><\/a> inizia con la comprensione di come i sistemi CA e CC si comportano diversamente sotto i transitori, in particolare l'estinzione dell'arco (AC zero-crossing vs DC senza zero-crossing) e la progettazione dei componenti (MOV bidirezionali vs unidirezionali). Questa guida spiega la differenza tra SPD CA e SPD CC, mappa gli standard IEC\/UL applicabili e mostra come selezionare un SPD che soddisfi le esigenze applicative e di conformit\u00e0.\r\n<h2>1. Introduzione<\/h2>\r\nTransient overvoltages, also known as power surges, are short-duration spikes in voltage that can damage or destroy sensitive electronic equipment. These surges can be caused by lightning strikes, grid switching operations, large load switching, or inductive equipment startups. SPD devices, also called surge suppressors or surge arresters, are engineered to detect and divert these spikes before they reach protected equipment.\r\n\r\nBut not all surges\u2014or SPDs\u2014are created equal. AC (Alternating Current) and DC (Direct Current) systems exhibit very different electrical behaviors and, as such, require distinct surge protection approaches. Per <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/26931\" target=\"_blank\" rel=\"noopener\"><strong><em>CEI EN 61643-11\/-31<\/em><\/strong><\/a>, un SPD limita la tensione di picco e devia la corrente di picco in nanosecondi, proteggendo le apparecchiature a valle.\r\n<h2>2. Che cos'\u00e8 la protezione da sovratensione CA?<\/h2>\r\n<a href=\"https:\/\/www.britecelectric.com\/it\/product-category\/ac-power-surge-protection\/\" rel=\"attachment wp-att-2114\"><img class=\"alignnone wp-image-2114\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2025\/06\/AC-Power-Surge-Protection-1024x1024.webp\" alt=\"\" width=\"600\" height=\"600\" \/><\/a>\r\n\r\n<a href=\"https:\/\/www.britecelectric.com\/it\/product-category\/ac-power-surge-protection\/\" target=\"_blank\" rel=\"noopener\"><em><strong data-start=\"218\" data-end=\"241\">Protezione contro le sovratensioni CA<\/strong><\/em><\/a> \u00e8 progettato per sistemi elettrici in cui la tensione alterna periodicamente la direzione, in genere a 50 Hz o 60 Hz. Questi sistemi sono ampiamente utilizzati in abitazioni residenziali, edifici commerciali, fabbriche e reti di automazione industriale. Secondo <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65314\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"490\" data-end=\"506\">CEI EN 61643-11<\/strong><\/a>, gli SPD CA sono classificati in Tipo 1, Tipo 2 e Tipo 3, ciascuno destinato a un diverso punto di installazione all'interno del sistema di distribuzione.\r\n<h3 data-start=\"652\" data-end=\"688\">Caratteristiche principali degli scaricatori AC<\/h3>\r\n<ul data-start=\"689\" data-end=\"1410\">\r\n \t<li data-start=\"689\" data-end=\"777\">\r\n<p data-start=\"691\" data-end=\"777\">Funziona con tensioni di rete comuni come 115 V, 230 V, 400 V e fino a 690 V CA.<\/p>\r\n<\/li>\r\n \t<li data-start=\"778\" data-end=\"857\">\r\n<p data-start=\"780\" data-end=\"857\">Funzionamento bidirezionale per gestire la commutazione della polarit\u00e0 delle onde sinusoidali CA.<\/p>\r\n<\/li>\r\n \t<li data-start=\"858\" data-end=\"983\">\r\n<p data-start=\"860\" data-end=\"983\">Estinzione dell'arco attraverso passaggi naturali per lo zero della forma d'onda AC, che rende la disconnessione pi\u00f9 sicura ed efficiente.<\/p>\r\n<\/li>\r\n \t<li data-start=\"984\" data-end=\"1220\">\r\n<p data-start=\"986\" data-end=\"1220\">MOV (varistori a ossido di metallo) comunemente utilizzati per assorbire l'energia di picco; negli SPD di Tipo 1, i MOV sono spesso combinati con GDT (tubi a scarica di gas) o camere ad arco per resistere agli impulsi dei fulmini ad alta energia (forme d'onda 10\/350 \u00b5s).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1221\" data-end=\"1410\">\r\n<p data-start=\"1223\" data-end=\"1410\">\u00c8 richiesto il coordinamento con la protezione a monte (interruttore automatico o fusibile); la pratica migliore \u00e8 mantenere la lunghezza del cavo dell'SPD quanto pi\u00f9 corta possibile, idealmente &lt;0,5 m, per ridurre al minimo la tensione residua.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<blockquote>\r\n<h3 data-start=\"1412\" data-end=\"1447\">Tipi di SPD per applicazioni CA<\/h3>\r\n<ul data-start=\"1448\" data-end=\"1800\">\r\n \t<li data-start=\"1448\" data-end=\"1558\">\r\n<p data-start=\"1450\" data-end=\"1558\"><strong data-start=\"1450\" data-end=\"1464\">SPD di tipo 1<\/strong> \u2013 Installato all'ingresso di servizio; resiste alle correnti dirette di fulmine (Iimp 10\/350 \u00b5s).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1559\" data-end=\"1689\">\r\n<p data-start=\"1561\" data-end=\"1689\"><strong data-start=\"1561\" data-end=\"1575\">SPD di tipo 2<\/strong> \u2013 Installato sui quadri di distribuzione; protegge dalle sovratensioni di manovra e dai fulmini indiretti (In\/Imax 8\/20 \u00b5s).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1690\" data-end=\"1800\">\r\n<p data-start=\"1692\" data-end=\"1800\"><strong data-start=\"1692\" data-end=\"1706\">SPD di tipo 3<\/strong> \u2013 Installato vicino ad apparecchiature sensibili; fornisce una protezione eccellente contro le sovratensioni residue.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"1802\" data-end=\"1828\">Applicazioni tipiche<\/h3>\r\n<ul data-start=\"1829\" data-end=\"2053\">\r\n \t<li data-start=\"1829\" data-end=\"1870\">\r\n<p data-start=\"1831\" data-end=\"1870\">Targhe di servizio principali (Tipologia 1)<\/p>\r\n<\/li>\r\n \t<li data-start=\"1871\" data-end=\"1912\">\r\n<p data-start=\"1873\" data-end=\"1912\">Quadri di distribuzione per edifici (Tipo 2)<\/p>\r\n<\/li>\r\n \t<li data-start=\"1913\" data-end=\"1967\">\r\n<p data-start=\"1915\" data-end=\"1967\">Quadri di controllo in ambienti industriali (Tipo 2)<\/p>\r\n<\/li>\r\n \t<li data-start=\"1968\" data-end=\"2053\">\r\n<p data-start=\"1970\" data-end=\"2053\">Protezione del punto di utilizzo o a livello di presa per dispositivi sensibili alimentati in CA (Tipo 3)<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2055\" data-end=\"2094\">Esempio da <span style=\"text-decoration: underline;\"><a href=\"https:\/\/www.britecelectric.com\/it\/product-category\/ac-power-surge-protection\/\" target=\"_blank\" rel=\"noopener\"><strong><em>Prodotto Britec AC SPD<\/em><\/strong><\/a> <\/span>Allineare<\/h3>\r\n<ul data-start=\"2095\" data-end=\"2701\">\r\n \t<li data-start=\"2095\" data-end=\"2257\">\r\n<p data-start=\"2097\" data-end=\"2257\"><strong data-start=\"2097\" data-end=\"2117\">BR-50GR (Tipo 1)<\/strong>: Approvato per Uc 275\/320\/440 V, con Iimp fino a 25 kA (10\/350 \u00b5s); ideale per la protezione contro i fulmini degli ingressi di servizio nei sistemi TN\/TT.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2258\" data-end=\"2392\">\r\n<p data-start=\"2260\" data-end=\"2392\"><strong data-start=\"2260\" data-end=\"2290\">BR-12.5M (ibrido di tipo 1+2)<\/strong>: Gestisce sia gli impulsi dei fulmini che le sovratensioni di commutazione, rendendolo adatto per impianti industriali.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2393\" data-end=\"2583\">\r\n<p data-start=\"2395\" data-end=\"2583\"><strong data-start=\"2395\" data-end=\"2425\">BR-40 e BR-30FU (Tipo 2)<\/strong>: dimensionato per Uc 275 V, con In 20 kA \/ Imax 40 kA (8\/20 \u00b5s); il BR-30FU integra un fusibile di riserva, semplificando l'installazione e migliorando la sicurezza.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2584\" data-end=\"2701\">\r\n<p data-start=\"2586\" data-end=\"2701\"><strong data-start=\"2586\" data-end=\"2613\">BR-230\/BR275-6 (Tipo 3)<\/strong>: Progettato per la protezione di apparecchiature terminali, con bassa tensione residua (Up \u2264 1,5 kV).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/blockquote>\r\n<h2>3. Che cos'\u00e8 la protezione da sovratensione CC?<\/h2>\r\n<a href=\"https:\/\/www.britecelectric.com\/it\/product-category\/dc-surge-protector\/\" rel=\"attachment wp-att-2113\"><img class=\"alignnone wp-image-2113\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2025\/06\/Surge-Protection-Devices-For-Solar-PV-1024x1024.webp\" alt=\"Dispositivi di protezione da sovratensione CC\" width=\"600\" height=\"600\" \/><\/a>\r\n\r\n<em><a href=\"https:\/\/www.britecelectric.com\/it\/product-category\/dc-surge-protector\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"361\" data-end=\"384\">Protezione contro le sovratensioni CC<\/strong><\/a><\/em> \u00e8 progettato per sistemi a corrente continua, dove l'elettricit\u00e0 scorre in un'unica direzione senza passaggi naturali per lo zero. A differenza dei sistemi CA che beneficiano di inversioni periodiche di tensione, i sistemi CC presentano una sfida ingegneristica unica: gli archi non si autoestinguono. Ci\u00f2 significa che gli SPD CC richiedono meccanismi di estinzione dell\u2019arco, disconnessione termica e rilascio meccanico pi\u00f9 robusti per garantire la sicurezza e prevenire l\u2019instabilit\u00e0 termica.\r\n<h3 data-start=\"820\" data-end=\"849\">Caratteristiche principali degli SPD CC<\/h3>\r\n<ul data-start=\"850\" data-end=\"1855\">\r\n \t<li data-start=\"850\" data-end=\"1011\">\r\n<p data-start=\"852\" data-end=\"1011\"><strong data-start=\"852\" data-end=\"871\">Valori di tensione<\/strong>: Tipicamente progettato per tensioni da 500 V CC a 1500 V CC, per pannelli solari fotovoltaici, sistemi di accumulo di batterie (BESS) e reti CC a ricarica rapida.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1012\" data-end=\"1174\">\r\n<p data-start=\"1014\" data-end=\"1174\"><strong data-start=\"1014\" data-end=\"1047\">Selezione MOV unidirezionale<\/strong>: Per soddisfare la polarit\u00e0 CC, gli SPD CC utilizzano MOV unidirezionali, garantendo il corretto bloccaggio dei picchi per il flusso di corrente unidirezionale.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1175\" data-end=\"1364\">\r\n<p data-start=\"1177\" data-end=\"1364\"><strong data-start=\"1177\" data-end=\"1196\">Soppressione dell'arco<\/strong>: Poich\u00e9 la CC non dispone di un passaggio per lo zero, gli SPD CC integrano sezionatori termici ad azione rapida, tubi a scarica di gas (GDT) o camere ad arco per interrompere in sicurezza le correnti di guasto.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1365\" data-end=\"1538\">\r\n<p data-start=\"1367\" data-end=\"1538\"><strong data-start=\"1367\" data-end=\"1390\">Gestione delle sovratensioni elevate<\/strong>: Costruito per assorbire sovratensioni ad alta energia con valori In\/Imax fino a 20\u201340 kA (8\/20 \u00b5s) e dispositivi di tipo 1+2 classificati per impulsi di fulmini Iimp.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1539\" data-end=\"1855\">\r\n<p data-start=\"1541\" data-end=\"1576\"><strong data-start=\"1541\" data-end=\"1573\">Conformit\u00e0 e Certificazione<\/strong>:<\/p>\r\n\r\n<ul data-start=\"1579\" data-end=\"1855\">\r\n \t<li data-start=\"1579\" data-end=\"1699\">\r\n<p data-start=\"1581\" data-end=\"1699\">Deve essere conforme alla norma IEC 61643-31 (per SPD CC fotovoltaici) o <a href=\"https:\/\/www.nemasurge.org\/ul-1449-transient-voltage-surge-suppressors\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"1635\" data-end=\"1646\">UL1449<\/strong><\/a> (per sistemi CC in Nord America, fino a 1500 V CC).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1702\" data-end=\"1855\">\r\n<p data-start=\"1704\" data-end=\"1855\">A seconda del progetto o dei requisiti regionali, i prodotti possono essere dotati di certificazioni aggiuntive T\u00dcV, CB o UL per la conformit\u00e0 della rete e gli audit di sicurezza.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"1857\" data-end=\"1906\">Applicazioni tipiche della protezione contro le sovratensioni CC<\/h3>\r\n<ul data-start=\"1907\" data-end=\"2261\">\r\n \t<li data-start=\"1907\" data-end=\"1999\">\r\n<p data-start=\"1909\" data-end=\"1999\">Array solari fotovoltaici (protezione di stringhe o quadri elettrici, in genere 1000 V CC o 1500 V CC).<\/p>\r\n<\/li>\r\n \t<li data-start=\"2000\" data-end=\"2084\">\r\n<p data-start=\"2002\" data-end=\"2084\">Sistemi di accumulo dell'energia a batteria (BESS) per soluzioni su scala di rete o microrete.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2085\" data-end=\"2162\">\r\n<p data-start=\"2087\" data-end=\"2162\">Stazioni di ricarica per veicoli elettrici (EV), in particolare ricarica rapida CC.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2163\" data-end=\"2261\">\r\n<p data-start=\"2165\" data-end=\"2261\">Torri per telecomunicazioni e sistemi di energia rinnovabile (convertitori per turbine eoliche, reti DC ibride).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2263\" data-end=\"2304\">Esempi da <span style=\"text-decoration: underline;\"><a href=\"https:\/\/www.britecelectric.com\/it\/product-category\/dc-surge-protector\/\" target=\"_blank\" rel=\"noopener\">SPD DC di Britec<\/a><\/span> Allineare<\/h3>\r\n<ul data-start=\"2305\" data-end=\"2976\">\r\n \t<li data-start=\"2305\" data-end=\"2630\">\r\n<p data-start=\"2307\" data-end=\"2341\"><a href=\"https:\/\/www.britecelectric.com\/it\/product\/brpv3-1000-20-1000v-20ka-t12-pv-surge-arrester\/\" target=\"_blank\" rel=\"noopener\"><em><strong data-start=\"2307\" data-end=\"2339\">BRPV3-1000 (SPD CC tipo 1+2)<\/strong><\/em><\/a><\/p>\r\n\r\n<ul data-start=\"2344\" data-end=\"2630\">\r\n \t<li data-start=\"2344\" data-end=\"2381\">\r\n<p data-start=\"2346\" data-end=\"2381\">Tensione nominale: Uc = 1000 Vcc<\/p>\r\n<\/li>\r\n \t<li data-start=\"2384\" data-end=\"2429\">\r\n<p data-start=\"2386\" data-end=\"2429\">Corrente nominale dispersa: In = 20 kA<\/p>\r\n<\/li>\r\n \t<li data-start=\"2432\" data-end=\"2489\">\r\n<p data-start=\"2434\" data-end=\"2489\">Corrente massima di scarica: Imax = 40 kA (8\/20 \u00b5s)<\/p>\r\n<\/li>\r\n \t<li data-start=\"2492\" data-end=\"2537\">\r\n<p data-start=\"2494\" data-end=\"2537\">Livello di protezione della tensione: Up \u2264 3,8 kV<\/p>\r\n<\/li>\r\n \t<li data-start=\"2540\" data-end=\"2630\">\r\n<p data-start=\"2542\" data-end=\"2630\">Caratteristiche: Sezionatore termico + segnalazione remota per monitoraggio in tempo reale.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"2632\" data-end=\"2976\">\r\n<p data-start=\"2634\" data-end=\"2668\"><a href=\"https:\/\/www.britecelectric.com\/it\/product\/brpv3-1500-12-5-t1t2-1500v-12-5ka-pv-surge-protection-device\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"2634\" data-end=\"2666\">BRPV3-1500 (SPD CC tipo 1+2)<\/strong><\/a><\/p>\r\n\r\n<ul data-start=\"2671\" data-end=\"2976\">\r\n \t<li data-start=\"2671\" data-end=\"2708\">\r\n<p data-start=\"2673\" data-end=\"2708\">Tensione nominale: Uc = 1500 Vcc<\/p>\r\n<\/li>\r\n \t<li data-start=\"2711\" data-end=\"2756\">\r\n<p data-start=\"2713\" data-end=\"2756\">Corrente nominale dispersa: In = 20 kA<\/p>\r\n<\/li>\r\n \t<li data-start=\"2759\" data-end=\"2806\">\r\n<p data-start=\"2761\" data-end=\"2806\">Corrente massima dispersa: Imax = 40 kA<\/p>\r\n<\/li>\r\n \t<li data-start=\"2809\" data-end=\"2854\">\r\n<p data-start=\"2811\" data-end=\"2854\">Livello di protezione della tensione: Up \u2264 4,5 kV<\/p>\r\n<\/li>\r\n \t<li data-start=\"2857\" data-end=\"2976\">\r\n<p data-start=\"2859\" data-end=\"2976\">Caratteristiche: Design della camera d'arco + interruttore termico, che garantisce un funzionamento affidabile negli impianti fotovoltaici e nelle infrastrutture per veicoli elettrici.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2>4. Qual \u00e8 la differenza tra protezione da sovratensione CA e CC?<\/h2>\r\nSebbene a prima vista gli SPD CA e gli SPD CC sembrino simili, i principi di progettazione, gli standard e i requisiti applicativi sono molto diversi. La tabella seguente riassume le principali differenze tra SPD CA e SPD CC:\r\n<table style=\"width: 100%; height: 336px;\">\r\n<thead>\r\n<tr style=\"height: 24px;\">\r\n<th style=\"height: 24px;\"><strong>Parametro<\/strong><\/th>\r\n<th style=\"height: 24px;\"><strong>SPD CA<\/strong><\/th>\r\n<th style=\"height: 24px;\"><strong>SPD CC<\/strong><\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Intervallo di tensione<\/strong><\/td>\r\n<td style=\"height: 48px;\">115 V \u2013 690 V CA (reti comuni) Esempio: BR-40 (Uc 275 V, In 20 kA)<\/td>\r\n<td style=\"height: 48px;\">500 V \u2013 1500 V CC (PV, EV, BESS) Esempio: BRPV3-1500 (Uc 1500 V CC, In 20 kA)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Gestione della polarit\u00e0<\/strong><\/td>\r\n<td style=\"height: 24px;\">Funzionamento bidirezionale (commutazione della polarit\u00e0 dell'onda sinusoidale CA)<\/td>\r\n<td style=\"height: 24px;\">Selezione MOV unidirezionale per la stabilit\u00e0 della polarit\u00e0 CC<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Estinzione dell'arco<\/strong><\/td>\r\n<td style=\"height: 48px;\">Il passaggio naturale per lo zero favorisce l'interruzione dell'arco Gli SPD di tipo 1 spesso utilizzano MOV + GDT\/camera d'arco per impulsi da 10\/350 \u00b5s<\/td>\r\n<td style=\"height: 48px;\">Nessun passaggio per lo zero \u2192 richiede un sezionatore termico rapido, una camera d'arco o un GDT<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Tempo di risposta<\/strong><\/td>\r\n<td style=\"height: 24px;\">Gli SPD basati su MOV generalmente rispondono in &lt;25 ns (a seconda del dispositivo)<\/td>\r\n<td style=\"height: 24px;\">Stesso principio: basato su MOV, &lt;25 ns (dipendente dal dispositivo)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Tipo di forma d'onda<\/strong><\/td>\r\n<td style=\"height: 24px;\">Sinusoidale (50\/60 Hz)<\/td>\r\n<td style=\"height: 24px;\">Tensione continua costante<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Forme d'onda del test di sovratensione<\/strong><\/td>\r\n<td style=\"height: 48px;\">8\/20 \u00b5s (a commutazione), 10\/350 \u00b5s (corrente da fulmine, tipo 1)<\/td>\r\n<td style=\"height: 48px;\">Standardizzato come AC (8\/20 \u00b5s, 10\/350 \u00b5s); differenza fondamentale = estinzione dell'arco<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Gestione dell'energia<\/strong><\/td>\r\n<td style=\"height: 48px;\">La classificazione per polo dipende dal design (controllare la scheda tecnica: In\/Imax\/Iimp) Esempio: <strong>BR-30FU (In 20 kA, Imax 40 kA)<\/strong><\/td>\r\n<td style=\"height: 48px;\">La classificazione per polo dipende dal design (In\/Imax\/Iimp) Esempio: BRPV3-1000 (In 20 kA, Imax 40 kA)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Standard<\/strong><\/td>\r\n<td style=\"height: 24px;\">IEC 61643-11 (SPD CA), UL 1449 (Nord America)<\/td>\r\n<td style=\"height: 24px;\">IEC 61643-31 (SPD CC, FV), UL 1449 (Nord America, FV \u22641500 V CC)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Applicazioni<\/strong><\/td>\r\n<td style=\"height: 24px;\">Abitazioni, uffici, quadri di controllo industriali, quadri di distribuzione di edifici<\/td>\r\n<td style=\"height: 24px;\">Pannelli solari fotovoltaici, accumulo di batterie, ricarica di veicoli elettrici, telecomunicazioni, turbine eoliche<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h3>4.1 Caratteristiche della corrente elettrica: CA e CC<\/h3>\r\nL'AC inverte periodicamente la direzione (onda sinusoidale), consentendo punti naturali di passaggio per lo zero. La corrente continua scorre in un'unica direzione in modo continuo (forma d'onda piatta), rendendo l'estinzione dell'arco molto pi\u00f9 impegnativa.\r\n\r\n<strong>Implicazione:<\/strong>\r\n<blockquote>Gli SPD CA beneficiano del passaggio per lo zero per l'interruzione dell'arco, mentre gli SPD CC richiedono meccanismi di soppressione dell'arco pi\u00f9 robusti a causa delle caratteristiche della forma d'onda.<\/blockquote>\r\n<h3>4.2 Forma d'onda di picco<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li>Le sovratensioni CA hanno spesso forme d'onda pi\u00f9 uniformi e sinusoidali.<\/li>\r\n \t<li>Le sovratensioni CC sono pi\u00f9 brevi, pi\u00f9 veloci e pi\u00f9 brusche con una tensione a sommit\u00e0 piatta<\/li>\r\n<\/ul>\r\n<strong>Necessit\u00e0 di tempo di risposta:<\/strong>\r\n<blockquote>Gli SPD CC in genere richiedono tempi di risposta pi\u00f9 rapidi (\u226425 ns) per la protezione dai transitori rapidi.<\/blockquote>\r\n<h3>4.3 Progettazione e principi di funzionamento degli SPD<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>SPD CA:<\/strong> Progettato per polarit\u00e0 di tensione simmetrica e ingresso sinusoidale<\/li>\r\n \t<li><strong>SPD CC:<\/strong> Costruito per circuiti sensibili alla polarit\u00e0 e flusso di corrente unidirezionale<\/li>\r\n<\/ul>\r\n<strong>Tecnologia utilizzata: <\/strong>Sia i dispositivi SPD CA che quelli CC utilizzano comunemente MOV (varistori a ossido di metallo), sezionatori termici e talvolta GDT (tubi a scarica di gas). Per comprendere come funzionano questi componenti all'interno di un dispositivo di protezione da sovratensione, consultare la nostra guida dettagliata su <strong><em><a href=\"https:\/\/www.britecelectric.com\/it\/blog\/how-does-spd-surge-protection-device-work\/\" target=\"_blank\" rel=\"noopener\">come funziona un SPD<\/a>.<\/em><\/strong>\r\n<h3>4.4 Valori di tensione e capacit\u00e0 di picco<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li>SPD CA: gamma da 115 V a 600 V<\/li>\r\n \t<li>SPD CC: gamma da 500 V a 1500 V<\/li>\r\n<\/ul>\r\n<strong>Esempio:<\/strong>\r\n<blockquote>DC SPD FLY1-40PV gestisce fino a 40kA; L'AC SPD USP2 arriva fino a 120 kA, a seconda del modello.<\/blockquote>\r\n<h3>4.5 Ambienti applicativi<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>SPD CA:<\/strong> Uffici, case, HVAC, pannelli di controllo<\/li>\r\n \t<li><strong>SPD CC:<\/strong> Energie rinnovabili, telecomunicazioni esterne, sistemi di trasporto<\/li>\r\n<\/ul>\r\n<strong>Tolleranza ambientale:<\/strong>\r\n<blockquote>Gli SPD CC solitamente supportano intervalli di temperatura e umidit\u00e0 relativa pi\u00f9 ampi a causa delle applicazioni esterne.<\/blockquote>\r\n<h3>4.6 Estinzione dell'arco<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>CA:<\/strong> L'arco si spegne naturalmente al passaggio per lo zero<\/li>\r\n \t<li><strong>CC:<\/strong> Richiede l'estinzione meccanica\/termica dell'arco a causa della mancanza di inversione di polarit\u00e0.<\/li>\r\n<\/ul>\r\n<strong>Perch\u00e9 \u00e8 importante:<\/strong>\r\n<blockquote>Una soppressione inadeguata dell'arco negli scaricatori di sovratensione CC pu\u00f2 causare instabilit\u00e0 termica e incendi.<\/blockquote>\r\n<h3>4.7 Standard, test e certificazione<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>Standard SPD CA:<\/strong> UL 1449, IEC 61643-11 (Tipo 1, 2, 3)<\/li>\r\n \t<li><strong>Standard SPD CC:<\/strong> EN 50539-11, IEC 61643-31, UL 1449 (messa a fuoco PV, BESS, EV)<\/li>\r\n<\/ul>\r\n<strong>Esempio:<\/strong>\r\n<blockquote>La classe di protezione dalle sovratensioni deve essere verificata tramite etichette SPD certificate TUV per la conformit\u00e0 alla rete.<\/blockquote>\r\n<h2>5. Come scegliere il giusto SPD<\/h2>\r\n<p data-start=\"408\" data-end=\"648\">La scelta del dispositivo di protezione contro le sovratensioni (SPD) corretto non riguarda solo la tensione nominale, ma coinvolge anche la posizione di installazione, il coordinamento della protezione e la conformit\u00e0 agli standard internazionali. Ecco i fattori chiave da considerare:<\/p>\r\n\r\n<h3 data-start=\"655\" data-end=\"700\">1. Abbina l'SPD alla tensione del tuo sistema<\/h3>\r\n<ul data-start=\"701\" data-end=\"1201\">\r\n \t<li data-start=\"701\" data-end=\"930\">\r\n<p data-start=\"703\" data-end=\"744\"><strong data-start=\"703\" data-end=\"742\">Sistemi AC (IEC 61643-11 \/ UL 1449)<\/strong><\/p>\r\n\r\n<ul data-start=\"747\" data-end=\"930\">\r\n \t<li data-start=\"747\" data-end=\"803\">\r\n<p data-start=\"749\" data-end=\"803\">230\/400 V (reti TN\/TT): Scegli <strong data-start=\"781\" data-end=\"793\">Uc 275 V<\/strong> modelli.<\/p>\r\n<\/li>\r\n \t<li data-start=\"806\" data-end=\"930\">\r\n<p data-start=\"808\" data-end=\"930\">Esempio: Britec BR-40\/30FU \u2013 SPD Tipo 2, Uc 275 V, In 20 kA, Imax 40 kA, con fusibile integrato per protezione di backup.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"931\" data-end=\"1201\">\r\n<p data-start=\"933\" data-end=\"987\"><strong data-start=\"933\" data-end=\"985\">Sistemi fotovoltaici CC (IEC 61643-31 \/ UL 1449 \u22641500 V CC)<\/strong><\/p>\r\n\r\n<ul data-start=\"990\" data-end=\"1201\">\r\n \t<li data-start=\"990\" data-end=\"1062\">\r\n<p data-start=\"992\" data-end=\"1062\">Array da 600 V CC, 1.000 V CC o 1.500 V CC: selezionare la classificazione CC Uc corrispondente.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1065\" data-end=\"1201\">\r\n<p data-start=\"1067\" data-end=\"1201\">Esempio: <strong data-start=\"1076\" data-end=\"1111\">Britec BRPV3-1000 (Uc 1000 Vcc)<\/strong> O <strong data-start=\"1115\" data-end=\"1143\">BRPV3-1500 (Uc 1500 Vcc)<\/strong> \u2013 SPD CC tipo 1+2 per quadri elettrici e inverter fotovoltaici.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"1203\" data-end=\"1342\"><strong data-start=\"1205\" data-end=\"1212\">Mancia<\/strong>: Controllare sempre che la Uc dell'SPD (tensione operativa continua) sia \u2265 1,2 \u00d7 tensione nominale del sistema per evitare un invecchiamento precoce.<\/p>\r\n\r\n<h3 data-start=\"1349\" data-end=\"1424\">2. Applicare la giusta classe di protezione (tipo) a ciascun livello di installazione<\/h3>\r\n<ul data-start=\"1425\" data-end=\"2052\">\r\n \t<li data-start=\"1425\" data-end=\"1627\">\r\n<p data-start=\"1427\" data-end=\"1469\">Tipo 1 (corrente da fulmine 10\/350 \u00b5s)<\/p>\r\n\r\n<ul data-start=\"1472\" data-end=\"1627\">\r\n \t<li data-start=\"1472\" data-end=\"1530\">\r\n<p data-start=\"1474\" data-end=\"1530\">Installato all'ingresso del servizio\/distribuzione principale.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1533\" data-end=\"1571\">\r\n<p data-start=\"1535\" data-end=\"1571\">Gestisce le correnti di fulmine dirette.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1574\" data-end=\"1627\">\r\n<p data-start=\"1576\" data-end=\"1627\">Esempio: <strong data-start=\"1585\" data-end=\"1610\">BR-12.5M Tipo 1+2 SPD<\/strong>, Iimp 12,5 kA.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"1628\" data-end=\"1865\">\r\n<p data-start=\"1630\" data-end=\"1669\">Tipo 2 (sovratensioni di commutazione 8\/20 \u00b5s)<\/p>\r\n\r\n<ul data-start=\"1672\" data-end=\"1865\">\r\n \t<li data-start=\"1672\" data-end=\"1719\">\r\n<p data-start=\"1674\" data-end=\"1719\">Installato sui quadri di distribuzione a pavimento.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1722\" data-end=\"1792\">\r\n<p data-start=\"1724\" data-end=\"1792\">Protegge da sovratensioni di commutazione e correnti residue di fulmine.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1795\" data-end=\"1865\">\r\n<p data-start=\"1797\" data-end=\"1865\">Esempio: <strong data-start=\"1806\" data-end=\"1831\">BR-40\/30FU SPD tipo 2<\/strong> (con sezionatore integrato).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"1866\" data-end=\"2052\">\r\n<p data-start=\"1868\" data-end=\"1895\">Tipo 3 (punto di utilizzo)<\/p>\r\n\r\n<ul data-start=\"1898\" data-end=\"2052\">\r\n \t<li data-start=\"1898\" data-end=\"1983\">\r\n<p data-start=\"1900\" data-end=\"1983\">Installato vicino ad apparecchiature sensibili (computer, server, dispositivi medici).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1986\" data-end=\"2052\">\r\n<p data-start=\"1988\" data-end=\"2052\">Protegge dalle sovratensioni residue non limitate dagli SPD a monte.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"2054\" data-end=\"2204\"><strong data-start=\"2056\" data-end=\"2076\">Regola ingegneristica<\/strong>: Se la lunghezza del cavo tra due livelli di protezione \u00e8 <strong data-start=\"2131\" data-end=\"2140\">&gt;<\/strong>10 m, installare SPD aggiuntivi su entrambe le estremit\u00e0 per garantire il coordinamento.<\/p>\r\n\r\n<h3 data-start=\"2211\" data-end=\"2261\">3. Garantire il coordinamento con interruttori e fusibili<\/h3>\r\n<ul data-start=\"2262\" data-end=\"2455\">\r\n \t<li data-start=\"2262\" data-end=\"2330\">\r\n<p data-start=\"2264\" data-end=\"2330\">Gli SPD devono essere coordinati con i fusibili MCB\/RCB\/backup a monte.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2331\" data-end=\"2455\">\r\n<p data-start=\"2333\" data-end=\"2455\">Alcuni modelli, come <strong data-start=\"2351\" data-end=\"2372\">Britec BR-40\/30FU<\/strong>, integrano sezionatori termici e protezione di backup, riducendo spazi e costi.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2462\" data-end=\"2496\">4. Conformit\u00e0 agli standard<\/h3>\r\n<ul data-start=\"2497\" data-end=\"2605\">\r\n \t<li data-start=\"2497\" data-end=\"2543\">\r\n<p data-start=\"2499\" data-end=\"2543\"><strong data-start=\"2499\" data-end=\"2510\">SPD CA<\/strong>: IEC 61643-11, UL 1449<\/p>\r\n<\/li>\r\n \t<li data-start=\"2544\" data-end=\"2605\">\r\n<p data-start=\"2546\" data-end=\"2605\"><strong data-start=\"2546\" data-end=\"2560\">SPD CC fotovoltaici<\/strong>: IEC 61643-31, UL 1449 (\u22641500 Vcc)<\/p>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"2607\" data-end=\"2731\">Assicurarsi sempre che l'SPD disponga delle certificazioni di test CE, UL o IEC adeguate, in particolare per i progetti internazionali.<\/p>\r\n\r\n<h3 data-start=\"2738\" data-end=\"2756\">Chiave da asporto<\/h3>\r\n<p data-start=\"2757\" data-end=\"2931\">Scegliere l'SPD giusto significa abbinare la tensione, selezionare il Tipo corretto per il livello di installazione, garantire un coordinamento adeguato e rispettare gli standard IEC\/UL.<\/p>\r\n<p data-start=\"2933\" data-end=\"3142\">Con <strong data-start=\"2938\" data-end=\"3007\">Portafoglio di Britec (BR-12.5M, BR-40\/30FU, BRPV3-1000, BRPV3-1500)<\/strong>, puoi coprire applicazioni solari residenziali, commerciali, industriali e fotovoltaiche con una protezione contro le sovratensioni certificata e ad alte prestazioni.<\/p>\r\n\r\n<h2>6. Conclusione<\/h2>\r\nI dispositivi di protezione da sovratensione CA e CC possono sembrare simili, ma servono sistemi fondamentalmente diversi. Gli SPD CA sono ottimizzati per applicazioni a onda sinusoidale negli edifici e nelle reti. Gli SPD CC sono progettati su misura per forme d'onda di tensione piatta nelle infrastrutture CC rinnovabili e ad alta tensione.\r\n\r\n<strong>La scelta dell'SPD corretto \u00e8 essenziale per salvaguardare le apparecchiature e mantenere la conformit\u00e0 agli standard di sicurezza.<\/strong>\r\n\r\nPer garantire una protezione ottimale:\r\n<ul data-spread=\"false\">\r\n \t<li>Abbina sempre il tipo di SPD al sistema attuale (AC o DC)<\/li>\r\n \t<li>Considerare la tensione nominale, le caratteristiche della forma d'onda e la capacit\u00e0 di assorbimento dell'energia richiesta.<\/li>\r\n \t<li>Scegli prodotti certificati (TUV, UL, CE) con classi di protezione da sovratensione adeguate.<\/li>\r\n<\/ul>\r\n<a href=\"https:\/\/www.britecelectric.com\/it\/contact-us\/\" target=\"_blank\" rel=\"noopener\"><strong>Hai bisogno di aiuto per selezionare il tuo SPD?<\/strong> Contatta un professionista elettrico certificato o un fornitore di protezione da sovratensione per trovare la giusta soluzione di protezione da sovratensione CC o CA per il tuo sistema.<\/a>","protected":false},"featured_media":2114,"parent":0,"menu_order":130,"template":"","meta":{"_acf_changed":false},"blog_category":[9],"class_list":["post-2112","blog","type-blog","status-publish","has-post-thumbnail","hentry","blog_category-industry-news"],"acf":{"des":"This blog compares AC and DC surge protection devices (SPDs), explaining their key differences in waveform, voltage range, arc handling, and application scenarios. Whether you're protecting a home, solar system, or EV charger, understanding how to choose the right SPD is essential for system safety and compliance with standards like IEC 61643 and UL 1449.","txt":"Surge protection is fundamental to the safety and uptime of modern electrical systems. Choosing the right <a href=\"https:\/\/www.britecelectric.com\/products\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"1300\" data-end=\"1333\">Surge Protective Device (SPD)<\/strong><\/a> starts with understanding how AC and DC systems behave differently under transients\u2014especially arc extinction (AC zero-crossing vs DC no zero-crossing) and component design (bi-directional vs uni-directional MOVs). This guide explains the difference between AC SPD and DC SPD, maps the IEC\/UL standards that apply, and shows how to select an SPD that meets your application and compliance needs.\r\n<h2>1. Introduction<\/h2>\r\nTransient overvoltages, also known as power surges, are short-duration spikes in voltage that can damage or destroy sensitive electronic equipment. These surges can be caused by lightning strikes, grid switching operations, large load switching, or inductive equipment startups. SPD devices, also called surge suppressors or surge arresters, are engineered to detect and divert these spikes before they reach protected equipment.\r\n\r\nBut not all surges\u2014or SPDs\u2014are created equal. AC (Alternating Current) and DC (Direct Current) systems exhibit very different electrical behaviors and, as such, require distinct surge protection approaches. Per <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/26931\" target=\"_blank\" rel=\"noopener\"><strong><em>IEC 61643-11\/-31<\/em><\/strong><\/a>, an SPD limits surge voltage and diverts surge current within nanoseconds, protecting downstream equipment.\r\n<h2>2. What Is AC Surge Protection?<\/h2>\r\n<a href=\"https:\/\/www.britecelectric.com\/product-category\/ac-power-surge-protection\/\" rel=\"attachment wp-att-2114\"><img class=\"alignnone wp-image-2114\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2025\/06\/AC-Power-Surge-Protection-1024x1024.webp\" alt=\"\" width=\"600\" height=\"600\" \/><\/a>\r\n\r\n<a href=\"https:\/\/www.britecelectric.com\/product-category\/ac-power-surge-protection\/\" target=\"_blank\" rel=\"noopener\"><em><strong data-start=\"218\" data-end=\"241\">AC surge protection<\/strong><\/em><\/a> is designed for electrical systems where voltage alternates direction periodically\u2014typically at 50Hz or 60Hz. These systems are widely used in residential homes, commercial buildings, factories, and industrial automation networks. According to <a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65314\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"490\" data-end=\"506\">IEC 61643-11<\/strong><\/a>, AC SPDs are classified into Type 1, Type 2, and Type 3, each intended for a different installation point within the distribution system.\r\n<h3 data-start=\"652\" data-end=\"688\">Key Characteristics of AC SPDs<\/h3>\r\n<ul data-start=\"689\" data-end=\"1410\">\r\n \t<li data-start=\"689\" data-end=\"777\">\r\n<p data-start=\"691\" data-end=\"777\">Operate within common grid voltages such as 115V, 230V, 400V, and up to 690V AC.<\/p>\r\n<\/li>\r\n \t<li data-start=\"778\" data-end=\"857\">\r\n<p data-start=\"780\" data-end=\"857\">Bi-directional operation to handle polarity switching of AC sine waves.<\/p>\r\n<\/li>\r\n \t<li data-start=\"858\" data-end=\"983\">\r\n<p data-start=\"860\" data-end=\"983\">Arc extinction through natural zero-crossings of the AC waveform, which makes disconnection safer and more efficient.<\/p>\r\n<\/li>\r\n \t<li data-start=\"984\" data-end=\"1220\">\r\n<p data-start=\"986\" data-end=\"1220\">Commonly used MOVs (Metal Oxide Varistors) to absorb surge energy; in Type 1 SPDs, MOVs are often combined with GDTs (Gas Discharge Tubes) or arc chambers to withstand high-energy lightning impulses (10\/350 \u00b5s waveforms).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1221\" data-end=\"1410\">\r\n<p data-start=\"1223\" data-end=\"1410\">Coordination with upstream protection (MCB or fuse) is required; best practice is to keep the SPD lead length as short as possible, ideally&lt;0.5 m, to minimize residual voltage.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<blockquote>\r\n<h3 data-start=\"1412\" data-end=\"1447\">SPD Types for AC Applications<\/h3>\r\n<ul data-start=\"1448\" data-end=\"1800\">\r\n \t<li data-start=\"1448\" data-end=\"1558\">\r\n<p data-start=\"1450\" data-end=\"1558\"><strong data-start=\"1450\" data-end=\"1464\">Type 1 SPD<\/strong> \u2013 Installed at the service entrance; withstands direct lightning currents (Iimp 10\/350 \u00b5s).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1559\" data-end=\"1689\">\r\n<p data-start=\"1561\" data-end=\"1689\"><strong data-start=\"1561\" data-end=\"1575\">Type 2 SPD<\/strong> \u2013 Installed at distribution boards; protects against switching surges and indirect lightning (In\/Imax 8\/20 \u00b5s).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1690\" data-end=\"1800\">\r\n<p data-start=\"1692\" data-end=\"1800\"><strong data-start=\"1692\" data-end=\"1706\">Type 3 SPD<\/strong> \u2013 Installed close to sensitive equipment; provides fine protection against residual surges.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"1802\" data-end=\"1828\">Typical Applications<\/h3>\r\n<ul data-start=\"1829\" data-end=\"2053\">\r\n \t<li data-start=\"1829\" data-end=\"1870\">\r\n<p data-start=\"1831\" data-end=\"1870\">Main service entrance panels (Type 1)<\/p>\r\n<\/li>\r\n \t<li data-start=\"1871\" data-end=\"1912\">\r\n<p data-start=\"1873\" data-end=\"1912\">Building distribution boards (Type 2)<\/p>\r\n<\/li>\r\n \t<li data-start=\"1913\" data-end=\"1967\">\r\n<p data-start=\"1915\" data-end=\"1967\">Control panels in industrial environments (Type 2)<\/p>\r\n<\/li>\r\n \t<li data-start=\"1968\" data-end=\"2053\">\r\n<p data-start=\"1970\" data-end=\"2053\">Point-of-use or socket-level protection for sensitive AC-powered devices (Type 3)<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2055\" data-end=\"2094\">Example from <span style=\"text-decoration: underline;\"><a href=\"https:\/\/www.britecelectric.com\/product-category\/ac-power-surge-protection\/\" target=\"_blank\" rel=\"noopener\"><strong><em>Britec AC SPD Product<\/em><\/strong><\/a> <\/span>Range<\/h3>\r\n<ul data-start=\"2095\" data-end=\"2701\">\r\n \t<li data-start=\"2095\" data-end=\"2257\">\r\n<p data-start=\"2097\" data-end=\"2257\"><strong data-start=\"2097\" data-end=\"2117\">BR-50GR (Type 1)<\/strong>: Rated for Uc 275\/320\/440 V, with Iimp up to 25 kA (10\/350 \u00b5s); ideal for service entrance lightning protection in TN\/TT systems.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2258\" data-end=\"2392\">\r\n<p data-start=\"2260\" data-end=\"2392\"><strong data-start=\"2260\" data-end=\"2290\">BR-12.5M (Type 1+2 hybrid)<\/strong>: Handles both lightning impulse and switching surges, making it suitable for industrial facilities.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2393\" data-end=\"2583\">\r\n<p data-start=\"2395\" data-end=\"2583\"><strong data-start=\"2395\" data-end=\"2425\">BR-40 and BR-30FU (Type 2)<\/strong>: Rated for Uc 275 V, with In 20 kA \/ Imax 40 kA (8\/20 \u00b5s); the BR-30FU integrates a backup fuse, simplifying installation and improving safety.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2584\" data-end=\"2701\">\r\n<p data-start=\"2586\" data-end=\"2701\"><strong data-start=\"2586\" data-end=\"2613\">BR-230\/BR275-6 (Type 3)<\/strong>: Designed for terminal equipment protection, with low residual voltage (Up \u2264 1.5 kV).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/blockquote>\r\n<h2>3. What Is DC Surge Protection?<\/h2>\r\n<a href=\"https:\/\/www.britecelectric.com\/product-category\/dc-surge-protector\/\" rel=\"attachment wp-att-2113\"><img class=\"alignnone wp-image-2113\" src=\"https:\/\/www.britecelectric.com\/wp-content\/uploads\/2025\/06\/Surge-Protection-Devices-For-Solar-PV-1024x1024.webp\" alt=\"DC Surge Protection Devices\" width=\"600\" height=\"600\" \/><\/a>\r\n\r\n<em><a href=\"https:\/\/www.britecelectric.com\/product-category\/dc-surge-protector\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"361\" data-end=\"384\">DC surge protection<\/strong><\/a><\/em> is designed for direct current systems, where electricity flows in a single direction without natural zero-crossings. Unlike AC systems that benefit from periodic voltage reversals, DC systems present a unique engineering challenge: arcs do not self-extinguish. This means that DC SPDs require more robust arc quenching, thermal disconnection, and mechanical release mechanisms to ensure safety and prevent thermal runaway.\r\n<h3 data-start=\"820\" data-end=\"849\">Key Features of DC SPDs<\/h3>\r\n<ul data-start=\"850\" data-end=\"1855\">\r\n \t<li data-start=\"850\" data-end=\"1011\">\r\n<p data-start=\"852\" data-end=\"1011\"><strong data-start=\"852\" data-end=\"871\">Voltage Ratings<\/strong>: Typically designed for 500 Vdc to 1500 Vdc, covering solar PV arrays, battery storage systems (BESS), and DC fast-charging networks.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1012\" data-end=\"1174\">\r\n<p data-start=\"1014\" data-end=\"1174\"><strong data-start=\"1014\" data-end=\"1047\">Unidirectional MOV selection<\/strong>: To accommodate DC polarity, DC SPDs use unidirectional MOVs, ensuring correct surge clamping for one-way current flow.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1175\" data-end=\"1364\">\r\n<p data-start=\"1177\" data-end=\"1364\"><strong data-start=\"1177\" data-end=\"1196\">Arc Suppression<\/strong>: Because DC lacks a zero-crossing, DC SPDs integrate fast-acting thermal disconnects, gas discharge tubes (GDTs), or arc chambers to safely break fault currents.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1365\" data-end=\"1538\">\r\n<p data-start=\"1367\" data-end=\"1538\"><strong data-start=\"1367\" data-end=\"1390\">High Surge Handling<\/strong>: Built to absorb high-energy surges with In\/Imax ratings up to 20\u201340 kA (8\/20 \u00b5s) and Type 1+2 devices rated for Iimp lightning impulses.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1539\" data-end=\"1855\">\r\n<p data-start=\"1541\" data-end=\"1576\"><strong data-start=\"1541\" data-end=\"1573\">Compliance and Certification<\/strong>:<\/p>\r\n\r\n<ul data-start=\"1579\" data-end=\"1855\">\r\n \t<li data-start=\"1579\" data-end=\"1699\">\r\n<p data-start=\"1581\" data-end=\"1699\">Must comply with IEC 61643-31 (for PV DC SPDs) or <a href=\"https:\/\/www.nemasurge.org\/ul-1449-transient-voltage-surge-suppressors\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"1635\" data-end=\"1646\">UL 1449<\/strong><\/a> (for DC systems in North America, up to 1500 Vdc).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1702\" data-end=\"1855\">\r\n<p data-start=\"1704\" data-end=\"1855\">Depending on project or regional requirements, products may carry additional T\u00dcV, CB, or UL certifications for grid compliance and safety audits.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"1857\" data-end=\"1906\">Typical Applications of DC Surge Protection<\/h3>\r\n<ul data-start=\"1907\" data-end=\"2261\">\r\n \t<li data-start=\"1907\" data-end=\"1999\">\r\n<p data-start=\"1909\" data-end=\"1999\">Solar PV arrays (string or combiner box protection, typically 1000 Vdc or 1500 Vdc).<\/p>\r\n<\/li>\r\n \t<li data-start=\"2000\" data-end=\"2084\">\r\n<p data-start=\"2002\" data-end=\"2084\">Battery Energy Storage Systems (BESS) for grid-scale or microgrid solutions.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2085\" data-end=\"2162\">\r\n<p data-start=\"2087\" data-end=\"2162\">Electric Vehicle (EV) charging stations, especially DC fast charging.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2163\" data-end=\"2261\">\r\n<p data-start=\"2165\" data-end=\"2261\">Telecom towers and renewable energy systems (wind turbine converters, hybrid DC networks).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2263\" data-end=\"2304\">Examples from <span style=\"text-decoration: underline;\"><a href=\"https:\/\/www.britecelectric.com\/product-category\/dc-surge-protector\/\" target=\"_blank\" rel=\"noopener\">Britec\u2019s DC SPD<\/a><\/span> Range<\/h3>\r\n<ul data-start=\"2305\" data-end=\"2976\">\r\n \t<li data-start=\"2305\" data-end=\"2630\">\r\n<p data-start=\"2307\" data-end=\"2341\"><a href=\"https:\/\/www.britecelectric.com\/product\/brpv3-1000-20-1000v-20ka-t12-pv-surge-arrester\/\" target=\"_blank\" rel=\"noopener\"><em><strong data-start=\"2307\" data-end=\"2339\">BRPV3-1000 (Type 1+2 DC SPD)<\/strong><\/em><\/a><\/p>\r\n\r\n<ul data-start=\"2344\" data-end=\"2630\">\r\n \t<li data-start=\"2344\" data-end=\"2381\">\r\n<p data-start=\"2346\" data-end=\"2381\">Voltage rating: Uc = 1000 Vdc<\/p>\r\n<\/li>\r\n \t<li data-start=\"2384\" data-end=\"2429\">\r\n<p data-start=\"2386\" data-end=\"2429\">Nominal discharge current: In = 20 kA<\/p>\r\n<\/li>\r\n \t<li data-start=\"2432\" data-end=\"2489\">\r\n<p data-start=\"2434\" data-end=\"2489\">Maximum discharge current: Imax = 40 kA (8\/20 \u00b5s)<\/p>\r\n<\/li>\r\n \t<li data-start=\"2492\" data-end=\"2537\">\r\n<p data-start=\"2494\" data-end=\"2537\">Voltage protection level: Up \u2264 3.8 kV<\/p>\r\n<\/li>\r\n \t<li data-start=\"2540\" data-end=\"2630\">\r\n<p data-start=\"2542\" data-end=\"2630\">Features: Thermal disconnector + remote signaling for real-time monitoring.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"2632\" data-end=\"2976\">\r\n<p data-start=\"2634\" data-end=\"2668\"><a href=\"https:\/\/www.britecelectric.com\/product\/brpv3-1500-12-5-t1t2-1500v-12-5ka-pv-surge-protection-device\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"2634\" data-end=\"2666\">BRPV3-1500 (Type 1+2 DC SPD)<\/strong><\/a><\/p>\r\n\r\n<ul data-start=\"2671\" data-end=\"2976\">\r\n \t<li data-start=\"2671\" data-end=\"2708\">\r\n<p data-start=\"2673\" data-end=\"2708\">Voltage rating: Uc = 1500 Vdc<\/p>\r\n<\/li>\r\n \t<li data-start=\"2711\" data-end=\"2756\">\r\n<p data-start=\"2713\" data-end=\"2756\">Nominal discharge current: In = 20 kA<\/p>\r\n<\/li>\r\n \t<li data-start=\"2759\" data-end=\"2806\">\r\n<p data-start=\"2761\" data-end=\"2806\">Maximum discharge current: Imax = 40 kA<\/p>\r\n<\/li>\r\n \t<li data-start=\"2809\" data-end=\"2854\">\r\n<p data-start=\"2811\" data-end=\"2854\">Voltage protection level: Up \u2264 4.5 kV<\/p>\r\n<\/li>\r\n \t<li data-start=\"2857\" data-end=\"2976\">\r\n<p data-start=\"2859\" data-end=\"2976\">Features: Arc chamber design + thermal cut-off, ensuring reliable operation in PV plants and EV infrastructure.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2>4. What\u2019s the Difference Between AC and DC Surge Protection?<\/h2>\r\nAlthough AC SPDs and DC SPDs look similar at first glance, their design principles, standards, and application requirements are very different. The table below summarizes the key differences between AC SPD and DC SPD:\r\n<table style=\"width: 100%; height: 336px;\">\r\n<thead>\r\n<tr style=\"height: 24px;\">\r\n<th style=\"height: 24px;\"><strong>Parameter<\/strong><\/th>\r\n<th style=\"height: 24px;\"><strong>AC SPD<\/strong><\/th>\r\n<th style=\"height: 24px;\"><strong>DC SPD<\/strong><\/th>\r\n<\/tr>\r\n<\/thead>\r\n<tbody>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Voltage Range<\/strong><\/td>\r\n<td style=\"height: 48px;\">115V \u2013 690V AC (common grids) Example: BR-40 (Uc 275 V, In 20 kA)<\/td>\r\n<td style=\"height: 48px;\">500V \u2013 1500V DC (PV, EV, BESS) Example: BRPV3-1500 (Uc 1500 Vdc, In 20 kA)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Polarity Handling<\/strong><\/td>\r\n<td style=\"height: 24px;\">Bi-directional operation (AC sine wave polarity switching)<\/td>\r\n<td style=\"height: 24px;\">Unidirectional MOV selection for DC polarity stability<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Arc Extinguishing<\/strong><\/td>\r\n<td style=\"height: 48px;\">Natural zero-crossing aids arc interruption Type 1 SPDs often use MOV + GDT\/arc chamber for 10\/350 \u00b5s impulses<\/td>\r\n<td style=\"height: 48px;\">No zero-crossing \u2192 requires fast thermal disconnector, arc chamber, or GDT<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Response Time<\/strong><\/td>\r\n<td style=\"height: 24px;\">MOV-based SPDs typically respond in &lt;25 ns (device-dependent)<\/td>\r\n<td style=\"height: 24px;\">Same principle \u2013 MOV-based, &lt;25 ns (device-dependent)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Waveform Type<\/strong><\/td>\r\n<td style=\"height: 24px;\">Sinusoidal (50\/60 Hz)<\/td>\r\n<td style=\"height: 24px;\">Constant DC voltage<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Surge Test Waveforms<\/strong><\/td>\r\n<td style=\"height: 48px;\">8\/20 \u00b5s (switching), 10\/350 \u00b5s (lightning current, Type 1)<\/td>\r\n<td style=\"height: 48px;\">Standardized same as AC (8\/20 \u00b5s, 10\/350 \u00b5s); key difference = arc extinction<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Energy Handling<\/strong><\/td>\r\n<td style=\"height: 48px;\">Per-pole rating depends on design (check datasheet: In\/Imax\/Iimp) Example: <strong>BR-30FU (In 20 kA, Imax 40 kA)<\/strong><\/td>\r\n<td style=\"height: 48px;\">Per-pole rating depends on design (In\/Imax\/Iimp) Example: BRPV3-1000 (In 20 kA, Imax 40 kA)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Standards<\/strong><\/td>\r\n<td style=\"height: 24px;\">IEC 61643-11 (AC SPDs), UL 1449 (North America)<\/td>\r\n<td style=\"height: 24px;\">IEC 61643-31 (DC SPDs, PV), UL 1449 (North America, PV \u22641500 Vdc)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Applications<\/strong><\/td>\r\n<td style=\"height: 24px;\">Homes, offices, industrial control panels, building distribution boards<\/td>\r\n<td style=\"height: 24px;\">Solar PV arrays, battery storage, EV charging, telecom, wind turbines<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h3>4.1 Electrical Current Characteristics: AC vs. DC<\/h3>\r\nAC reverses direction periodically (sine wave), allowing natural zero-crossing points. DC flows in a single direction continuously (flat waveform), making arc extinguishing much more challenging.\r\n\r\n<strong>Implication:<\/strong>\r\n<blockquote>AC SPDs benefit from zero-crossing for arc interruption, while DC SPDs require more robust arc suppression mechanisms due to waveform characteristics.<\/blockquote>\r\n<h3>4.2 Surge Waveform<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li>AC surges often have smoother, sinusoidal waveforms.<\/li>\r\n \t<li>DC surges are shorter, faster, and more abrupt with flat top voltage<\/li>\r\n<\/ul>\r\n<strong>Response Time Needs:<\/strong>\r\n<blockquote>DC SPDs typically require faster response times (\u226425ns) to protect against rapid transients.<\/blockquote>\r\n<h3>4.3 Design and Operating Principles of SPDs<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC SPD:<\/strong> Designed for symmetrical voltage polarity and sine wave input<\/li>\r\n \t<li><strong>DC SPD:<\/strong> Built for polarity-sensitive circuits and unidirectional current flow<\/li>\r\n<\/ul>\r\n<strong>Technology Used: <\/strong>Both AC and DC SPD devices commonly use MOVs (metal oxide varistors), thermal disconnects, and sometimes GDTs (gas discharge tubes). To understand how these components function inside a surge protection device, see our detailed guide on <strong><em><a href=\"https:\/\/www.britecelectric.com\/blog\/how-does-spd-surge-protection-device-work\/\" target=\"_blank\" rel=\"noopener\">how an SPD works<\/a>.<\/em><\/strong>\r\n<h3>4.4 Voltage Ratings and Surge Capacity<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li>AC SPDs: Range from 115V to 600V<\/li>\r\n \t<li>DC SPDs: Range from 500V to 1500V<\/li>\r\n<\/ul>\r\n<strong>Example:<\/strong>\r\n<blockquote>DC SPD FLY1-40PV handles up to 40kA; AC SPD USP2 ranges up to 120kA, depending on the model.<\/blockquote>\r\n<h3>4.5 Application Environments<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC SPD:<\/strong> Offices, homes, HVAC, control panels<\/li>\r\n \t<li><strong>DC SPD:<\/strong> Renewable energy, outdoor telecom, transportation systems<\/li>\r\n<\/ul>\r\n<strong>Environmental Tolerance:<\/strong>\r\n<blockquote>DC SPDs usually support wider temperature ranges and relative humidity due to outdoor applications.<\/blockquote>\r\n<h3>4.6 Arc Extinguishing<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC:<\/strong> Arc naturally extinguishes at the zero-crossing<\/li>\r\n \t<li><strong>DC:<\/strong> Requires mechanical\/thermal arc quenching due to lack of polarity reversal.<\/li>\r\n<\/ul>\r\n<strong>Why It Matters:<\/strong>\r\n<blockquote>Inadequate arc suppression in DC surge arresters can lead to thermal runaway and fire.<\/blockquote>\r\n<h3>4.7 Standards, Testing, and Certification<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC SPD Standards:<\/strong> UL 1449, IEC 61643-11 (Type 1, 2, 3)<\/li>\r\n \t<li><strong>DC SPD Standards:<\/strong> EN 50539-11, IEC 61643-31, UL 1449 (PV, BESS, EV focus)<\/li>\r\n<\/ul>\r\n<strong>Example:<\/strong>\r\n<blockquote>Surge protection class must be verified via TUV-certified SPD labels for grid compliance.<\/blockquote>\r\n<h2>5. How to Choose the Right SPD<\/h2>\r\n<p data-start=\"408\" data-end=\"648\">Selecting the correct Surge Protective Device (SPD) is not only about voltage rating \u2013 it also involves installation position, protection coordination, and compliance with international standards. Here are the key factors to consider:<\/p>\r\n\r\n<h3 data-start=\"655\" data-end=\"700\">1. Match the SPD to Your System Voltage<\/h3>\r\n<ul data-start=\"701\" data-end=\"1201\">\r\n \t<li data-start=\"701\" data-end=\"930\">\r\n<p data-start=\"703\" data-end=\"744\"><strong data-start=\"703\" data-end=\"742\">AC systems (IEC 61643-11 \/ UL 1449)<\/strong><\/p>\r\n\r\n<ul data-start=\"747\" data-end=\"930\">\r\n \t<li data-start=\"747\" data-end=\"803\">\r\n<p data-start=\"749\" data-end=\"803\">230\/400 V (TN\/TT grids): Choose <strong data-start=\"781\" data-end=\"793\">Uc 275 V<\/strong> models.<\/p>\r\n<\/li>\r\n \t<li data-start=\"806\" data-end=\"930\">\r\n<p data-start=\"808\" data-end=\"930\">Example: Britec BR-40\/30FU \u2013 Type 2 SPD, Uc 275 V, In 20 kA, Imax 40 kA, with integrated fuse for backup protection.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"931\" data-end=\"1201\">\r\n<p data-start=\"933\" data-end=\"987\"><strong data-start=\"933\" data-end=\"985\">PV DC systems (IEC 61643-31 \/ UL 1449 \u22641500 Vdc)<\/strong><\/p>\r\n\r\n<ul data-start=\"990\" data-end=\"1201\">\r\n \t<li data-start=\"990\" data-end=\"1062\">\r\n<p data-start=\"992\" data-end=\"1062\">600 Vdc, 1000 Vdc, or 1500 Vdc arrays: Select matching DC Uc rating.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1065\" data-end=\"1201\">\r\n<p data-start=\"1067\" data-end=\"1201\">Example: <strong data-start=\"1076\" data-end=\"1111\">Britec BRPV3-1000 (Uc 1000 Vdc)<\/strong> or <strong data-start=\"1115\" data-end=\"1143\">BRPV3-1500 (Uc 1500 Vdc)<\/strong> \u2013 Type 1+2 DC SPDs for PV combiner boxes and inverters.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"1203\" data-end=\"1342\"><strong data-start=\"1205\" data-end=\"1212\">Tip<\/strong>: Always check that the SPD\u2019s Uc (continuous operating voltage) is \u2265 1.2 \u00d7 nominal system voltage to avoid premature ageing.<\/p>\r\n\r\n<h3 data-start=\"1349\" data-end=\"1424\">2. Apply the Right Protection Class (Type) to Each Installation Level<\/h3>\r\n<ul data-start=\"1425\" data-end=\"2052\">\r\n \t<li data-start=\"1425\" data-end=\"1627\">\r\n<p data-start=\"1427\" data-end=\"1469\">Type 1 (10\/350 \u00b5s lightning current)<\/p>\r\n\r\n<ul data-start=\"1472\" data-end=\"1627\">\r\n \t<li data-start=\"1472\" data-end=\"1530\">\r\n<p data-start=\"1474\" data-end=\"1530\">Installed at service entrance \/ main distribution.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1533\" data-end=\"1571\">\r\n<p data-start=\"1535\" data-end=\"1571\">Handles direct lightning currents.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1574\" data-end=\"1627\">\r\n<p data-start=\"1576\" data-end=\"1627\">Example: <strong data-start=\"1585\" data-end=\"1610\">BR-12.5M Type 1+2 SPD<\/strong>, Iimp 12.5 kA.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"1628\" data-end=\"1865\">\r\n<p data-start=\"1630\" data-end=\"1669\">Type 2 (8\/20 \u00b5s switching surges)<\/p>\r\n\r\n<ul data-start=\"1672\" data-end=\"1865\">\r\n \t<li data-start=\"1672\" data-end=\"1719\">\r\n<p data-start=\"1674\" data-end=\"1719\">Installed at floor distribution boards.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1722\" data-end=\"1792\">\r\n<p data-start=\"1724\" data-end=\"1792\">Protects against switching surges and residual lightning currents.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1795\" data-end=\"1865\">\r\n<p data-start=\"1797\" data-end=\"1865\">Example: <strong data-start=\"1806\" data-end=\"1831\">BR-40\/30FU Type 2 SPD<\/strong> (with integrated disconnector).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li data-start=\"1866\" data-end=\"2052\">\r\n<p data-start=\"1868\" data-end=\"1895\">Type 3 (point-of-use)<\/p>\r\n\r\n<ul data-start=\"1898\" data-end=\"2052\">\r\n \t<li data-start=\"1898\" data-end=\"1983\">\r\n<p data-start=\"1900\" data-end=\"1983\">Installed close to sensitive equipment (computers, servers, medical devices).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1986\" data-end=\"2052\">\r\n<p data-start=\"1988\" data-end=\"2052\">Protects against residual surges not clamped by upstream SPDs.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"2054\" data-end=\"2204\"><strong data-start=\"2056\" data-end=\"2076\">Engineering rule<\/strong>: If the cable length between two protection stages is <strong data-start=\"2131\" data-end=\"2140\">&gt;<\/strong>10 m, install additional SPDs at both ends to ensure coordination.<\/p>\r\n\r\n<h3 data-start=\"2211\" data-end=\"2261\">3. Ensure Coordination With Breakers &amp; Fuses<\/h3>\r\n<ul data-start=\"2262\" data-end=\"2455\">\r\n \t<li data-start=\"2262\" data-end=\"2330\">\r\n<p data-start=\"2264\" data-end=\"2330\">SPDs must be coordinated with upstream MCB\/RCB\/backup fuses.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2331\" data-end=\"2455\">\r\n<p data-start=\"2333\" data-end=\"2455\">Some models, like <strong data-start=\"2351\" data-end=\"2372\">Britec BR-40\/30FU<\/strong>, integrate thermal disconnectors and backup protection, reducing space and cost.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2462\" data-end=\"2496\">4. Compliance With Standards<\/h3>\r\n<ul data-start=\"2497\" data-end=\"2605\">\r\n \t<li data-start=\"2497\" data-end=\"2543\">\r\n<p data-start=\"2499\" data-end=\"2543\"><strong data-start=\"2499\" data-end=\"2510\">AC SPDs<\/strong>: IEC 61643-11, UL 1449<\/p>\r\n<\/li>\r\n \t<li data-start=\"2544\" data-end=\"2605\">\r\n<p data-start=\"2546\" data-end=\"2605\"><strong data-start=\"2546\" data-end=\"2560\">PV DC SPDs<\/strong>: IEC 61643-31, UL 1449 (\u22641500 Vdc)<\/p>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"2607\" data-end=\"2731\">Always ensure the SPD carries the proper CE, UL, or IEC test certifications, especially for international projects.<\/p>\r\n\r\n<h3 data-start=\"2738\" data-end=\"2756\">Key Takeaway<\/h3>\r\n<p data-start=\"2757\" data-end=\"2931\">Choosing the right SPD means matching the voltage, selecting the correct Type per installation level, ensuring proper coordination, and complying with IEC\/UL standards.<\/p>\r\n<p data-start=\"2933\" data-end=\"3142\">With <strong data-start=\"2938\" data-end=\"3007\">Britec\u2019s portfolio (BR-12.5M, BR-40\/30FU, BRPV3-1000, BRPV3-1500)<\/strong>, you can cover residential, commercial, industrial, and PV solar applications with certified, high-performance surge protection.<\/p>\r\n\r\n<h2>6. Conclusion<\/h2>\r\nAC and DC surge protection devices may look similar, but they serve fundamentally different systems. AC SPDs are optimized for sine wave applications in buildings and grids. DC SPDs are tailored for flat voltage waveforms in renewable and high-voltage DC infrastructures.\r\n\r\n<strong>Choosing the correct SPD is essential to safeguarding equipment and maintaining compliance with safety standards.<\/strong>\r\n\r\nTo ensure optimal protection:\r\n<ul data-spread=\"false\">\r\n \t<li>Always match the SPD type to the current system (AC or DC)<\/li>\r\n \t<li>Consider voltage rating, waveform characteristics, and required energy absorption capability.<\/li>\r\n \t<li>Choose certified products (TUV, UL, CE) with appropriate surge protection class ratings.<\/li>\r\n<\/ul>\r\n<a href=\"https:\/\/www.britecelectric.com\/contact-us\/\" target=\"_blank\" rel=\"noopener\"><strong>Need help selecting your SPD?<\/strong> Contact a certified electrical professional or surge protection provider to find the right DC surge protection or AC surge protection solution for your system.<\/a>"},"_links":{"self":[{"href":"https:\/\/www.britecelectric.com\/it\/wp-json\/wp\/v2\/blog\/2112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/it\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/it\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/it\/wp-json\/wp\/v2\/media\/2114"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/it\/wp-json\/wp\/v2\/media?parent=2112"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/it\/wp-json\/wp\/v2\/blog_category?post=2112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}