{"id":2551,"date":"2026-08-04T09:40:07","date_gmt":"2026-08-04T01:40:07","guid":{"rendered":"https:\/\/www.britecelectric.com\/?post_type=blog&p=2551"},"modified":"2026-08-26T13:14:15","modified_gmt":"2026-08-26T05:14:15","slug":"do-you-need-type-1-surge-protection-device-in-lightning-prone-regions","status":"publish","type":"blog","link":"https:\/\/www.britecelectric.com\/da\/blog\/do-you-need-type-1-surge-protection-device-in-lightning-prone-regions\/","title":{"rendered":"Do You Need Type 1 Surge Protection Device in Lightning-Prone Regions?"},"content":{"rendered":"If your facility is located in a region with frequent thunderstorms, the question is not whether you need surge protection, but whether a standard Type 2 SPD is sufficient or whether a Type 1 oversp\u00e6ndingsbeskyttelsesanordning<\/strong> is required at the service entrance. The answer depends on three factors defined by IEC 62305<\/strong> og IEC 61643-11<\/strong>: whether your building has an external lightning protection system, whether power is supplied via overhead lines, and the local lightning density (keraunic level). This guide explains exactly when a Type 1 SPD is mandatory, what happens if you install the wrong type, and how to select the right configuration for your installation. For an overview of all SPD types, see our surge protection device overview<\/a>.\r\n
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Protect Your Facility From Direct Lightning Current<\/p>\r\n

Britec Electric manufactures IEC 61643-11 certified Type 1 SPDs rated at Iimp 25kA (10\/350\u00b5s), engineered for installations in high-lightning regions worldwide. Our BR-25M series handles partial lightning current at the service entrance, protecting your downstream equipment and Type 2 SPDs from catastrophic failure.<\/p>\r\nRequest a Free Quote<\/a>\r\n\r\n<\/div>\r\n

What Makes a Region \"Lightning-Prone\"?<\/h2>\r\nLightning activity varies dramatically across the globe. The keraunic level<\/strong> (also called thunderstorm days, Td) is the traditional metric: the average number of days per year on which thunder is heard at a given location. According to data from NASA and Vaisala, the global distribution ranges from near zero in polar regions to over 200 days per year in the tropics.\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Region \/ Country<\/th>\r\nKeraunic Level (Td)<\/th>\r\nLightning Density (flashes\/km\u00b2\/yr)<\/th>\r\nType 1 SPD Recommendation<\/th>\r\n<\/tr>\r\n<\/thead>\r\n
Central Africa (DRC, Cameroon)<\/td>\r\n150\u2013200+<\/td>\r\n50\u2013205<\/td>\r\nMandatory<\/td>\r\n<\/tr>\r\n
Southeast Asia (Singapore, Malaysia, Indonesia)<\/td>\r\n150\u2013180<\/td>\r\n20\u201380<\/td>\r\nMandatory<\/td>\r\n<\/tr>\r\n
Florida, USA (\"Lightning Alley\")<\/td>\r\n80\u2013100<\/td>\r\n9\u201324<\/td>\r\nMandatory<\/td>\r\n<\/tr>\r\n
Northern Australia (Darwin)<\/td>\r\n80<\/td>\r\n15\u201330<\/td>\r\nMandatory<\/td>\r\n<\/tr>\r\n
Central Europe (Germany, Austria, Switzerland)<\/td>\r\n15\u201335<\/td>\r\n2\u20135<\/td>\r\nRisk assessment required<\/td>\r\n<\/tr>\r\n
South America (Brazil, Colombia, Venezuela)<\/td>\r\n80\u2013297 (Lake Maracaibo)<\/td>\r\n15\u2013233<\/td>\r\nMandatory<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\nAs a practical rule, when the keraunic level exceeds 25 thunderstorm days per year<\/strong>, a formal lightning risk assessment<\/a> per IEC 62305-2 should be conducted. In regions above 50 Td, a Type 1 SPD at the service entrance is recommended as a baseline, even before completing the full risk calculation.\r\n\r\n\"BR-25M<\/a>\r\n

When Is a Type 1 SPD Mandatory?<\/h2>\r\nIf\u00f8lge IEC 60364-5-53<\/strong> og IEC 62305-4<\/strong>, a Type 1 SPD is mandatory at the main distribution board (LPZ 0 \u2192 LPZ 1 boundary) under two specific conditions:\r\n

1. The Building Has an External Lightning Protection System (LPS)<\/h3>\r\nWhen a building is equipped with an external lightning protection system comprising air terminals (lightning rods), down conductors, and an earth termination network per IEC 62305-3, a direct lightning strike to the air terminal will inject partial lightning current into the building's electrical system through the common earthing network. This partial current has the 10\/350 microsecond waveform and can reach tens of kiloamperes. Only a Type 1 SPD certified to IEC 61643-11 Class I can safely discharge this energy to earth without catastrophic failure.\r\n

2. The Building Is Supplied by Overhead Power Lines<\/h3>\r\nOverhead power lines are directly exposed to lightning. A direct strike to the line, or a nearby strike that induces surge current through electromagnetic coupling, can propagate the 10\/350 microsecond lightning waveform into the building's main distribution board. IEC 60364-5-53 requires a Type 1 SPD at or near the origin of the electrical installation whenever overhead supply lines are present, regardless of whether the building itself has an external LPS.\r\n
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Key distinction:<\/strong> A building with underground supply and no external LPS may be protected by a Type 2 SPD at the MDB, subject to risk assessment. However, in high-keraunic regions, even underground cables can carry induced lightning current through ground potential rise, making a combined Type 1+2 SPD the safer engineering choice.<\/p>\r\n\r\n<\/div>\r\n

Why Type 2 SPDs Cannot Substitute for Type 1<\/h2>\r\nThe critical technical difference between Type 1 and Type 2 SPDs is the test waveform<\/strong>. IEC 61643-11 defines:\r\n