{"id":7911,"date":"2025-11-05T01:24:31","date_gmt":"2025-11-05T01:24:31","guid":{"rendered":"https:\/\/www.raxpower.com\/?page_id=7911"},"modified":"2026-08-12T04:27:53","modified_gmt":"2026-08-12T04:27:53","slug":"para-raios-de-linha-com-gap-externo","status":"publish","type":"page","link":"https:\/\/www.raxpower.com\/pt\/surge-arrester-cutout\/externally-gapped-line-arrester\/","title":{"rendered":"Para-raios de Linha com Espa\u00e7o Externo"},"content":{"rendered":"
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Externally Gapped Line Arrester<\/h2>\n\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div><\/div>
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An Externally Gapped Line Arrester (EGLA) protects transmission lines from lightning discharges and transient overvoltages by combining a series varistor unit (SVU) with metal-oxide varistor (MOV) blocks and an external series gap. This configuration prevents insulator flashovers and reduces momentary interruptions without requiring a direct line-to-ground connection or disconnector.<\/p>\n

The series gap galvanically isolates the MOV from system voltage under normal conditions, eliminating the disconnector and ground lead required by non-gapped line arresters (NGLA). This produces a lighter, more compact design that reduces tower and conductor loads while avoiding temporary overvoltage (TOV) concerns. Energy handling is defined by charge transfer rating, and since the SVU remains isolated, thermal recovery is not a factor.<\/p>\n

During a lightning surge, the series gap flashes over at a predetermined voltage, allowing the MOV elements to conduct surge current to ground. The MOV limits follow current and extinguishes the external power arc within milliseconds, maintaining continuous service without substation breaker operation. This mechanism controls overvoltages below the insulator’s lightning-impulse withstand level.<\/p>\n

The EGLA’s zero watts-loss design supports energy efficiency while improving line performance by reducing lightning and switching surge outages. The compact configuration facilitates installation on various tower types, including those with short clearances in extra-high voltage (EHV) and ultra-high voltage (UHV) networks up to 765 kV, particularly in areas with high lightning activity or poor grounding conditions.<\/p>\n\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div>