Electrical line surge arrester EGLA

compactMOVhigh-voltage

Externally Gapped Line Arrester (EGLA)–Insulated from the high-voltage line by series gap Siemens Energy EGLA line surge arresters have an external spark gap placed in series that galvanically isolates the active part of the line surge arrester from the line voltage under normal conditions. In case of lightning, the spark gap flashes over and the arrester limits the ground fault current from several kA to a few amperes, and extinguishes the arc within 10 ms such that no circuit breaker operation at both line ends is needed, i.e. no reclosing operation. Benefits: • No leakage current, since the series gap disconnects the arrester part of the EGLA - metal-oxide varistor (MOV) blocks - from the system voltage under normal service conditions • Lower arrester rated voltage required (arrester is not energized all the time, i.e. it's insulated by the series GAP) --> less material and fewer MOVs are needed • No disconnector and no ground lead are needed • Suitable for multiple-circuit towers with short clearances - the highly compact design of the EGLA and the absence of a ground lead allow installation and lightning protection even on towers with very small cross-arm clearances • Better suited for live installation • Complete EGLA solutions with polymer insulators also available • Designed and tested to comply with the latest IEC 60099-8 standard