Surge protection

High DC voltage combined with special characteristic of the PV modules challenge the surge protection.

Standard EN50539-11 defines two types, Type 1 lightning arrester and Type 2 surge arrester. We offer

  • Combination lightning/surge arrester Type 1/2
  • Surge arrester Type 2


In most cases, the surge protection device is installed close either to the inverter or close the PV modules. If the cables between the PV modules and the inverter exceed 10 m, an additional surge protection device should be installed, a requirement in EN50539-12. Surges and transients can be induced onto long cable runs even after the first surge protection device started to operate, these can be handled by a second surge protection device.

Keep in mind that one set of surge protection devices are required for each MPP input of the inverter.

When PV modules are installed on a building with an external lightning rod, it is important that there is a separation distance according to IEC62305-2 between the PV modules and the lightning protection system. If the separation distance is not kept, Type 1 lightning arrester should be used. If the building is not equipped with external lightning protection system or if the separation distance is kept, Type 2 surge arrester can be installed.

Product specialist
Börje Jansson