Medium-voltage surge arresters

Surge arresters are designed to prevent ground faults and short circuits in power lines caused by lightning or switching overvoltages. Insulator flashovers, voltage dips and interruptions are prevented by eliminating all lightning and switching overvoltages above the insulator insulation level.

Siemens Energy surge arresters are maintenance free and there are no serviceable parts in it. Visual examinations regarding outer damages or extreme pollutions may be carried out at regular intervals. If there is any monitoring device installed the specific rules of the system/device apply.

The failure rate of our high voltage surge arresters is estimated to be far lower as 0.1% per year, which corresponds to a mean time between failure (MTBF) of more than 1000 years. More specific figures cannot be given, since the total number of reported arrester failures by our customers is by far too low to perform statistic calculations with sufficient accuracy.

The reported and investigated arrester failures were mainly caused by exceeding the electrical specification (e.g. by direct lightning stroke, voltage transfer) or loss of tightness by external stresses (e.g. by transport damage). Consequently, the inherent failure rate of Siemens high voltage surge arresters is virtually zero and can be neglected.

Based on service experience as well as inspections and test on surge arresters taken back from service, the life expectancy of our high voltage surge arresters is considered to be at least 40 years.

Siemens Energy surge arresters can ideally protect valuable equipment against overvoltages, such as transformers, circuit breakers, generators, motors, capacitors, traction vehicles, bushings and complete switchgear.

In 1925, an exciting journey began at Schaltwerk Berlin: the development of the first surge arrester (cathode arrester) - the beginning of arrester manufacturing at Siemens Energy. Today, 100 years later, our surge arresters are an indispensable core element for a safe and sustainable energy supply worldwide. We are the market leader - and with good reason: quality, innovation and decades of experience.

Porcelain and polymer are common; polymer offers better resistance to pollution and lighter weight, while porcelain provides mechanical robustness.

They absorb and divert the high-energy lightning surge currents, withstanding impulse voltages up to hundreds of kV peak.

Polymer arresters are lighter, have better pollution resistance, and lower risk of shattering, making them suitable for polluted or coastal areas.