{"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\/da\/blog\/ac-vs-dc-surge-protection-whats-the-difference\/","title":{"rendered":"AC vs. DC Surge Protection: What&#8217;s the Difference?"},"content":{"rendered":"Oversp\u00e6ndingsbeskyttelse er grundl\u00e6ggende for sikkerheden og oppetiden for moderne elektriske systemer. At v\u00e6lge det rigtige <a href=\"https:\/\/www.britecelectric.com\/da\/products\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"1300\" data-end=\"1333\">Surge Protective Device (SPD)<\/strong><\/a> starter med at forst\u00e5, hvordan AC- og DC-systemer opf\u00f8rer sig forskelligt under transienter - is\u00e6r bueudslettelse (AC nul-gennemgang vs DC ingen nul-gennemgang) og komponentdesign (tovejs vs ensrettet MOV'er). Denne vejledning forklarer forskellen mellem AC SPD og DC SPD, kortl\u00e6gger de g\u00e6ldende IEC\/UL-standarder og viser, hvordan du v\u00e6lger en SPD, der opfylder dine applikations- og overholdelsesbehov.\r\n<h2>1. Introduktion<\/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>, en SPD begr\u00e6nser oversp\u00e6ndingssp\u00e6ndingen og afleder oversp\u00e6ndingsstr\u00f8mmen inden for nanosekunder, hvilket beskytter downstream-udstyr.\r\n<h2>2. Hvad er AC Surge Protection?<\/h2>\r\n<a href=\"https:\/\/www.britecelectric.com\/da\/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\/da\/product-category\/ac-power-surge-protection\/\" target=\"_blank\" rel=\"noopener\"><em><strong data-start=\"218\" data-end=\"241\">AC oversp\u00e6ndingsbeskyttelse<\/strong><\/em><\/a> er designet til elektriske systemer, hvor sp\u00e6ndingen skifter retning periodisk - typisk ved 50Hz eller 60Hz. Disse systemer er meget udbredt i boliger, kommercielle bygninger, fabrikker og industrielle automationsnetv\u00e6rk. If\u00f8lge <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 SPD'er er klassificeret i Type 1, Type 2 og Type 3, hver beregnet til et andet installationspunkt i distributionssystemet.\r\n<h3 data-start=\"652\" data-end=\"688\">N\u00f8glekarakteristika for AC SPD'er<\/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\">Arbejd inden for almindelige netsp\u00e6ndinger s\u00e5som 115V, 230V, 400V og op til 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\">Tovejsdrift til at h\u00e5ndtere polaritetsskift af AC sinusb\u00f8lger.<\/p>\r\n<\/li>\r\n \t<li data-start=\"858\" data-end=\"983\">\r\n<p data-start=\"860\" data-end=\"983\">Bueudryddelse gennem naturlige nulkrydsninger af AC-b\u00f8lgeformen, hvilket g\u00f8r frakobling sikrere og mere effektiv.<\/p>\r\n<\/li>\r\n \t<li data-start=\"984\" data-end=\"1220\">\r\n<p data-start=\"986\" data-end=\"1220\">Almindeligt anvendte MOV'er (Metal Oxide Varistors) til at absorbere b\u00f8lgeenergi; i Type 1 SPD'er kombineres MOV'er ofte med GDT'er (Gas Discharge Tubes) eller lysbuekamre for at modst\u00e5 lynimpulser med h\u00f8j energi (10\/350 \u00b5s b\u00f8lgeformer).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1221\" data-end=\"1410\">\r\n<p data-start=\"1223\" data-end=\"1410\">Koordinering med opstr\u00f8ms beskyttelse (MCB eller sikring) er p\u00e5kr\u00e6vet; bedste praksis er at holde SPD-ledningsl\u00e6ngden s\u00e5 kort som muligt, ideelt &lt;0,5 m, for at minimere resterende sp\u00e6nding.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<blockquote>\r\n<h3 data-start=\"1412\" data-end=\"1447\">SPD-typer til AC-applikationer<\/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 Installeret ved serviceindgangen; modst\u00e5r direkte lynstr\u00f8mme (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 Installeret ved fordelingstavler; beskytter mod koblingsst\u00f8d og indirekte lyn (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 Installeret t\u00e6t p\u00e5 f\u00f8lsomt udstyr; giver fin beskyttelse mod resterende oversp\u00e6ndinger.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"1802\" data-end=\"1828\">Typiske applikationer<\/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\">Hovedserviceindgangspaneler (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\">Bygningsfordelingstavler (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\">Kontrolpaneler i industrielle milj\u00f8er (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\">Beskyttelse ved brugssted eller stikkontakt til f\u00f8lsomme vekselstr\u00f8msdrevne enheder (Type 3)<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2055\" data-end=\"2094\">Eksempel fra <span style=\"text-decoration: underline;\"><a href=\"https:\/\/www.britecelectric.com\/da\/product-category\/ac-power-surge-protection\/\" target=\"_blank\" rel=\"noopener\"><strong><em>Britec AC SPD produkt<\/em><\/strong><\/a> <\/span>R\u00e6kkevidde<\/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>: Nominel til Uc 275\/320\/440 V, med Iimp op til 25 kA (10\/350 \u00b5s); ideel til lynbeskyttelse i TN\/TT-systemer.<\/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>: H\u00e5ndterer b\u00e5de lynimpulser og koblingsst\u00f8d, hvilket g\u00f8r den velegnet til industrielle faciliteter.<\/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 og BR-30FU (Type 2)<\/strong>: Nominel til Uc 275 V, med In 20 kA \/ Imax 40 kA (8\/20 \u00b5s); BR-30FU integrerer en reservesikring, hvilket forenkler installationen og forbedrer sikkerheden.<\/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>: Designet til beskyttelse af terminaludstyr, med lav restsp\u00e6nding (op \u2264 1,5 kV).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/blockquote>\r\n<h2>3. Hvad er DC Surge Protection?<\/h2>\r\n<a href=\"https:\/\/www.britecelectric.com\/da\/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-oversp\u00e6ndingsbeskyttelsesenheder\" width=\"600\" height=\"600\" \/><\/a>\r\n\r\n<em><a href=\"https:\/\/www.britecelectric.com\/da\/product-category\/dc-surge-protector\/\" target=\"_blank\" rel=\"noopener\"><strong data-start=\"361\" data-end=\"384\">DC oversp\u00e6ndingsbeskyttelse<\/strong><\/a><\/em> er designet til j\u00e6vnstr\u00f8mssystemer, hvor elektriciteten flyder i en enkelt retning uden naturlige nulgennemgange. I mods\u00e6tning til AC-systemer, der nyder godt af periodiske sp\u00e6ndingsvendinger, udg\u00f8r DC-systemer en unik teknisk udfordring: lysbuer slukker ikke selv. Dette betyder, at DC SPD'er kr\u00e6ver mere robust bueslukning, termisk frakobling og mekaniske udl\u00f8sningsmekanismer for at sikre sikkerhed og forhindre termisk l\u00f8b.\r\n<h3 data-start=\"820\" data-end=\"849\">N\u00f8glefunktioner ved DC SPD'er<\/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\">Sp\u00e6ndingsv\u00e6rdier<\/strong>: Typisk designet til 500 Vdc til 1500 Vdc, der d\u00e6kker solcellepaneler, batterilagringssystemer (BESS) og DC-hurtigopladningsnetv\u00e6rk.<\/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\">Envejs MOV-valg<\/strong>: For at im\u00f8dekomme DC-polaritet bruger DC SPD'er ensrettede MOV'er, hvilket sikrer korrekt oversp\u00e6ndingssp\u00e6nding for envejsstr\u00f8m.<\/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\">Bueundertrykkelse<\/strong>: Fordi DC mangler en nulgennemgang, integrerer DC SPD'er hurtigvirkende termiske afbrydere, gasudladningsr\u00f8r (GDT'er) eller lysbuekamre for sikkert at bryde fejlstr\u00f8mme.<\/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\">H\u00e5ndtering af h\u00f8j sp\u00e6nding<\/strong>: Bygget til at absorbere h\u00f8jenergisp\u00e6ndinger med In\/Imax-klassificeringer p\u00e5 op til 20\u201340 kA (8\/20 \u00b5s) og Type 1+2-enheder, der er klassificeret til Iimp-lynimpulser.<\/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\">Overholdelse og certificering<\/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\">Skal overholde IEC 61643-31 (for PV DC SPD'er) eller <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-systemer i Nordamerika, op til 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\">Afh\u00e6ngigt af projektkrav eller regionale krav kan produkter b\u00e6re yderligere T\u00dcV-, CB- eller UL-certificeringer til netoverholdelse og sikkerhedsaudits.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"1857\" data-end=\"1906\">Typiske anvendelser af DC-oversp\u00e6ndingsbeskyttelse<\/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 (streng- eller kombineringsboksbeskyttelse, typisk 1000 Vdc eller 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) til netskala- eller mikronetl\u00f8sninger.<\/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) ladestationer, is\u00e6r DC hurtigopladning.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2163\" data-end=\"2261\">\r\n<p data-start=\"2165\" data-end=\"2261\">Telet\u00e5rne \u200b\u200bog vedvarende energisystemer (vindm\u00f8lleomformere, hybride j\u00e6vnstr\u00f8msnetv\u00e6rk).<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2263\" data-end=\"2304\">Eksempler fra <span style=\"text-decoration: underline;\"><a href=\"https:\/\/www.britecelectric.com\/da\/product-category\/dc-surge-protector\/\" target=\"_blank\" rel=\"noopener\">Britecs DC SPD<\/a><\/span> R\u00e6kkevidde<\/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\/da\/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\">Sp\u00e6ndingsm\u00e6rke: 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\">Nominel afladestr\u00f8m: 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\">Maksimal afladningsstr\u00f8m: 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\">Sp\u00e6ndingsbeskyttelsesniveau: Op \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\">Funktioner: Termisk afbryder + fjernsignalering til overv\u00e5gning i realtid.<\/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\/da\/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\">Sp\u00e6ndingsm\u00e6rke: 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\">Nominel afladestr\u00f8m: 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\">Maksimal afladningsstr\u00f8m: 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\">Sp\u00e6ndingsbeskyttelsesniveau: Op \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\">Funktioner: Buekammerdesign + termisk afsk\u00e6ring, der sikrer p\u00e5lidelig drift i PV-anl\u00e6g og EV-infrastruktur.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2>4. Hvad er forskellen mellem AC og DC Surge Protection?<\/h2>\r\nSelvom AC SPD'er og DC SPD'er ligner hinanden ved f\u00f8rste \u00f8jekast, er deres designprincipper, standarder og anvendelseskrav meget forskellige. Tabellen nedenfor opsummerer de vigtigste forskelle mellem AC SPD og 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>Sp\u00e6ndingsomr\u00e5de<\/strong><\/td>\r\n<td style=\"height: 48px;\">115V \u2013 690V AC (f\u00e6lles net) Eksempel: BR-40 (Uc 275 V, i 20 kA)<\/td>\r\n<td style=\"height: 48px;\">500V \u2013 1500V DC (PV, EV, BESS) Eksempel: 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>Polaritetsh\u00e5ndtering<\/strong><\/td>\r\n<td style=\"height: 24px;\">Tovejsdrift (AC sinusb\u00f8lge polaritetsskift)<\/td>\r\n<td style=\"height: 24px;\">Envejs MOV-valg for DC-polaritetsstabilitet<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Bueslukning<\/strong><\/td>\r\n<td style=\"height: 48px;\">Naturlige nulkrydsningshj\u00e6lpemidler til lysbueafbrydelse Type 1 SPD'er bruger ofte MOV + GDT\/buekammer til 10\/350 \u00b5s impulser<\/td>\r\n<td style=\"height: 48px;\">Ingen nulgennemgang \u2192 kr\u00e6ver hurtig termisk afbryder, lysbuekammer eller GDT<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Svartid<\/strong><\/td>\r\n<td style=\"height: 24px;\">MOV-baserede SPD'er reagerer typisk i &lt;25 ns (enhedsafh\u00e6ngig)<\/td>\r\n<td style=\"height: 24px;\">Samme princip \u2013 MOV-baseret, &lt;25 ns (enhedsafh\u00e6ngig)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>B\u00f8lgeform type<\/strong><\/td>\r\n<td style=\"height: 24px;\">Sinusformet (50\/60 Hz)<\/td>\r\n<td style=\"height: 24px;\">Konstant j\u00e6vnsp\u00e6nding<\/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 (lynstr\u00f8m, Type 1)<\/td>\r\n<td style=\"height: 48px;\">Standardiseret samme som AC (8\/20 \u00b5s, 10\/350 \u00b5s); n\u00f8gleforskel = bueudryddelse<\/td>\r\n<\/tr>\r\n<tr style=\"height: 48px;\">\r\n<td style=\"height: 48px;\"><strong>Energih\u00e5ndtering<\/strong><\/td>\r\n<td style=\"height: 48px;\">Per-pol rating afh\u00e6nger af design (tjek datablad: In\/Imax\/Iimp) Eksempel: <strong>BR-30FU (i 20 kA, Imax 40 kA)<\/strong><\/td>\r\n<td style=\"height: 48px;\">Per-pol rating afh\u00e6nger af design (In\/Imax\/Iimp) Eksempel: 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>Standarder<\/strong><\/td>\r\n<td style=\"height: 24px;\">IEC 61643-11 (AC SPD'er), UL 1449 (Nordamerika)<\/td>\r\n<td style=\"height: 24px;\">IEC 61643-31 (DC SPD'er, PV), UL 1449 (Nordamerika, PV \u22641500 Vdc)<\/td>\r\n<\/tr>\r\n<tr style=\"height: 24px;\">\r\n<td style=\"height: 24px;\"><strong>Ans\u00f8gninger<\/strong><\/td>\r\n<td style=\"height: 24px;\">Boliger, kontorer, industrielle kontrolpaneler, bygningsfordelingstavler<\/td>\r\n<td style=\"height: 24px;\">Solcellepaneler, batteriopbevaring, EV-opladning, telekom, vindm\u00f8ller<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h3>4.1 Elektriske str\u00f8mkarakteristika: AC vs. DC<\/h3>\r\nAC vender periodisk retning (sinusb\u00f8lge), hvilket tillader naturlige nulkrydsningspunkter. DC str\u00f8mmer i en enkelt retning kontinuerligt (flad b\u00f8lgeform), hvilket g\u00f8r lysbueslukning meget mere udfordrende.\r\n\r\n<strong>Implikation:<\/strong>\r\n<blockquote>AC SPD'er drager fordel af nul-krydsning for bueafbrydelse, mens DC SPD'er kr\u00e6ver mere robuste bueundertrykkelsesmekanismer p\u00e5 grund af b\u00f8lgeformskarakteristika.<\/blockquote>\r\n<h3>4.2 Oversp\u00e6ndingsb\u00f8lgeform<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li>AC-st\u00f8d har ofte j\u00e6vnere, sinusformede b\u00f8lgeformer.<\/li>\r\n \t<li>DC-sp\u00e6ndinger er kortere, hurtigere og mere bratte med flad topsp\u00e6nding<\/li>\r\n<\/ul>\r\n<strong>Behov for responstid:<\/strong>\r\n<blockquote>DC SPD'er kr\u00e6ver typisk hurtigere responstider (\u226425ns) for at beskytte mod hurtige transienter.<\/blockquote>\r\n<h3>4.3 Design og driftsprincipper for SPD'er<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC SPD:<\/strong> Designet til symmetrisk sp\u00e6ndingspolaritet og sinusb\u00f8lgeindgang<\/li>\r\n \t<li><strong>DC SPD:<\/strong> Bygget til polaritetsf\u00f8lsomme kredsl\u00f8b og ensrettet str\u00f8m<\/li>\r\n<\/ul>\r\n<strong>Anvendt teknologi: <\/strong>B\u00e5de AC- og DC SPD-enheder bruger almindeligvis MOV'er (metaloxidvaristorer), termiske afbrydere og nogle gange GDT'er (gasudladningsr\u00f8r). For at forst\u00e5, hvordan disse komponenter fungerer inde i en oversp\u00e6ndingsbeskyttelsesenhed, se vores detaljerede vejledning om <strong><em><a href=\"https:\/\/www.britecelectric.com\/da\/blog\/how-does-spd-surge-protection-device-work\/\" target=\"_blank\" rel=\"noopener\">hvordan en SPD fungerer<\/a>.<\/em><\/strong>\r\n<h3>4.4 Sp\u00e6ndingsv\u00e6rdier og oversp\u00e6ndingskapacitet<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li>AC SPD'er: R\u00e6kkevidde fra 115V til 600V<\/li>\r\n \t<li>DC SPD'er: R\u00e6kkevidde fra 500V til 1500V<\/li>\r\n<\/ul>\r\n<strong>Eksempel:<\/strong>\r\n<blockquote>DC SPD FLY1-40PV h\u00e5ndterer op til 40kA; AC SPD USP2 r\u00e6kker op til 120kA, afh\u00e6ngigt af modellen.<\/blockquote>\r\n<h3>4.5 Applikationsmilj\u00f8er<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC SPD:<\/strong> Kontorer, boliger, VVS, kontrolpaneler<\/li>\r\n \t<li><strong>DC SPD:<\/strong> Vedvarende energi, udend\u00f8rs telekommunikation, transportsystemer<\/li>\r\n<\/ul>\r\n<strong>Milj\u00f8tolerance:<\/strong>\r\n<blockquote>DC SPD'er underst\u00f8tter normalt bredere temperaturomr\u00e5der og relativ luftfugtighed p\u00e5 grund af udend\u00f8rs applikationer.<\/blockquote>\r\n<h3>4.6 Bueslukning<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC:<\/strong> Buen slukker naturligt ved nul-krydsningen<\/li>\r\n \t<li><strong>DC:<\/strong> Kr\u00e6ver mekanisk\/termisk bueslukning p\u00e5 grund af manglende polaritetsvending.<\/li>\r\n<\/ul>\r\n<strong>Hvorfor det betyder noget:<\/strong>\r\n<blockquote>Utilstr\u00e6kkelig bueundertrykkelse i DC-oversp\u00e6ndingsafledere kan f\u00f8re til termisk l\u00f8b og brand.<\/blockquote>\r\n<h3>4.7 Standarder, test og certificering<\/h3>\r\n<ul data-spread=\"false\">\r\n \t<li><strong>AC SPD-standarder:<\/strong> UL 1449, IEC 61643-11 (Type 1, 2, 3)<\/li>\r\n \t<li><strong>DC SPD-standarder:<\/strong> EN 50539-11, IEC 61643-31, UL 1449 (PV, BESS, EV fokus)<\/li>\r\n<\/ul>\r\n<strong>Eksempel:<\/strong>\r\n<blockquote>Oversp\u00e6ndingsbeskyttelsesklasse skal verificeres via TUV-certificerede SPD-m\u00e6rker for netoverholdelse.<\/blockquote>\r\n<h2>5. S\u00e5dan v\u00e6lger du den rigtige SPD<\/h2>\r\n<p data-start=\"408\" data-end=\"648\">Valg af den korrekte oversp\u00e6ndingsbeskyttelsesanordning (SPD) handler ikke kun om sp\u00e6ndingsklassificering - det involverer ogs\u00e5 installationsposition, beskyttelseskoordinering og overholdelse af internationale standarder. Her er de vigtigste faktorer at overveje:<\/p>\r\n\r\n<h3 data-start=\"655\" data-end=\"700\">1. Tilpas SPD'en til dit systemsp\u00e6nding<\/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-systemer (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 net): V\u00e6lg <strong data-start=\"781\" data-end=\"793\">Uc 275 V<\/strong> modeller.<\/p>\r\n<\/li>\r\n \t<li data-start=\"806\" data-end=\"930\">\r\n<p data-start=\"808\" data-end=\"930\">Eksempel: Britec BR-40\/30FU \u2013 Type 2 SPD, Uc 275 V, In 20 kA, Imax 40 kA, med integreret sikring til backup beskyttelse.<\/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-systemer (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 eller 1500 Vdc arrays: V\u00e6lg matchende DC Uc-klassificering.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1065\" data-end=\"1201\">\r\n<p data-start=\"1067\" data-end=\"1201\">Eksempel: <strong data-start=\"1076\" data-end=\"1111\">Britec BRPV3-1000 (Uc 1000 Vdc)<\/strong> eller <strong data-start=\"1115\" data-end=\"1143\">BRPV3-1500 (Uc 1500 Vdc)<\/strong> \u2013 Type 1+2 DC SPD'er til PV-kombinationsbokse og invertere.<\/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>: Kontroller altid, at SPD'ens Uc (kontinuerlig driftssp\u00e6nding) er \u2265 1,2 \u00d7 nominel systemsp\u00e6nding for at undg\u00e5 for tidlig \u00e6ldning.<\/p>\r\n\r\n<h3 data-start=\"1349\" data-end=\"1424\">2. Anvend den rigtige beskyttelsesklasse (type) p\u00e5 hvert installationsniveau<\/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 lynstr\u00f8m)<\/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\">Monteres ved serviceindgang\/hovedfordeling.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1533\" data-end=\"1571\">\r\n<p data-start=\"1535\" data-end=\"1571\">H\u00e5ndterer direkte lynstr\u00f8mme.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1574\" data-end=\"1627\">\r\n<p data-start=\"1576\" data-end=\"1627\">Eksempel: <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 koblingsst\u00f8d)<\/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\">Monteres ved gulvfordelingstavler.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1722\" data-end=\"1792\">\r\n<p data-start=\"1724\" data-end=\"1792\">Beskytter mod koblingsst\u00f8d og resterende lynstr\u00f8mme.<\/p>\r\n<\/li>\r\n \t<li data-start=\"1795\" data-end=\"1865\">\r\n<p data-start=\"1797\" data-end=\"1865\">Eksempel: <strong data-start=\"1806\" data-end=\"1831\">BR-40\/30FU Type 2 SPD<\/strong> (med integreret afbryder).<\/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 (brugssted)<\/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\">Installeret t\u00e6t p\u00e5 f\u00f8lsomt udstyr (computere, servere, medicinsk udstyr).<\/p>\r\n<\/li>\r\n \t<li data-start=\"1986\" data-end=\"2052\">\r\n<p data-start=\"1988\" data-end=\"2052\">Beskytter mod resterende oversp\u00e6ndinger, der ikke er fastsp\u00e6ndt af opstr\u00f8ms SPD'er.<\/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\">Teknisk regel<\/strong>: Hvis kabell\u00e6ngden mellem to beskyttelsestrin er <strong data-start=\"2131\" data-end=\"2140\">&gt;<\/strong>10 m, installer yderligere SPD'er i begge ender for at sikre koordinering.<\/p>\r\n\r\n<h3 data-start=\"2211\" data-end=\"2261\">3. S\u00f8rg for koordinering med afbrydere og sikringer<\/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\">SPD'er skal koordineres med opstr\u00f8ms MCB\/RCB\/backup sikringer.<\/p>\r\n<\/li>\r\n \t<li data-start=\"2331\" data-end=\"2455\">\r\n<p data-start=\"2333\" data-end=\"2455\">Nogle modeller, f.eks <strong data-start=\"2351\" data-end=\"2372\">Britec BR-40\/30FU<\/strong>, integrere termiske afbrydere og backup-beskyttelse, hvilket reducerer plads og omkostninger.<\/p>\r\n<\/li>\r\n<\/ul>\r\n<h3 data-start=\"2462\" data-end=\"2496\">4. Overholdelse af standarder<\/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 SPD'er<\/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 SPD'er<\/strong>: IEC 61643-31, UL 1449 (\u22641500 Vdc)<\/p>\r\n<\/li>\r\n<\/ul>\r\n<p data-start=\"2607\" data-end=\"2731\">S\u00f8rg altid for, at SPD'en b\u00e6rer de korrekte CE-, UL- eller IEC-testcertificeringer, is\u00e6r til internationale projekter.<\/p>\r\n\r\n<h3 data-start=\"2738\" data-end=\"2756\">N\u00f8gle takeaway<\/h3>\r\n<p data-start=\"2757\" data-end=\"2931\">At v\u00e6lge den rigtige SPD betyder at matche sp\u00e6ndingen, v\u00e6lge den korrekte type pr. installationsniveau, sikre korrekt koordinering og overholde IEC\/UL-standarder.<\/p>\r\n<p data-start=\"2933\" data-end=\"3142\">Med <strong data-start=\"2938\" data-end=\"3007\">Britecs portef\u00f8lje (BR-12.5M, BR-40\/30FU, BRPV3-1000, BRPV3-1500)<\/strong>, kan du d\u00e6kke bolig-, erhvervs-, industri- og solcelleanl\u00e6g med certificeret, h\u00f8jtydende oversp\u00e6ndingsbeskyttelse.<\/p>\r\n\r\n<h2>6. Konklusion<\/h2>\r\nAC- og DC-oversp\u00e6ndingsbeskyttelsesenheder kan se ens ud, men de tjener fundamentalt forskellige systemer. AC SPD'er er optimeret til sinusb\u00f8lgeapplikationer i bygninger og net. DC SPD'er er skr\u00e6ddersyet til flade sp\u00e6ndingsb\u00f8lgeformer i vedvarende og h\u00f8jsp\u00e6ndings DC-infrastrukturer.\r\n\r\n<strong>At v\u00e6lge den korrekte SPD er afg\u00f8rende for at sikre udstyr og opretholde overholdelse af sikkerhedsstandarder.<\/strong>\r\n\r\nFor at sikre optimal beskyttelse:\r\n<ul data-spread=\"false\">\r\n \t<li>Tilpas altid SPD-typen til det aktuelle system (AC eller DC)<\/li>\r\n \t<li>Overvej sp\u00e6ndingsm\u00e6rke, b\u00f8lgeformskarakteristika og den n\u00f8dvendige energiabsorptionsevne.<\/li>\r\n \t<li>V\u00e6lg certificerede produkter (TUV, UL, CE) med passende oversp\u00e6ndingsbeskyttelsesklassificeringer.<\/li>\r\n<\/ul>\r\n<a href=\"https:\/\/www.britecelectric.com\/da\/contact-us\/\" target=\"_blank\" rel=\"noopener\"><strong>Har du brug for hj\u00e6lp til at v\u00e6lge din SPD?<\/strong> Kontakt en certificeret elektriker eller leverand\u00f8r af oversp\u00e6ndingsbeskyttelse for at finde den rigtige DC-oversp\u00e6ndingsbeskyttelse eller AC-oversp\u00e6ndingsbeskyttelsesl\u00f8sning til dit system.<\/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\/da\/wp-json\/wp\/v2\/blog\/2112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/da\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/da\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/da\/wp-json\/wp\/v2\/media\/2114"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/da\/wp-json\/wp\/v2\/media?parent=2112"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/da\/wp-json\/wp\/v2\/blog_category?post=2112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}