Lightning Rod and Surge Arrester Relationship: Not Alternatives, But Complementary

[Asım Aksu]

In lightning protection, lightning rods and surge arresters are two separate protection elements that perform different functions. The lightning rod system is used to safely capture direct lightning strikes to the structure and to transfer the lightning current to the ground via down conductors. Surge arresters (SPDs), on the other hand, help limit sudden overvoltages that may occur in the electrical installation, protecting panels and connected electrical/electronic devices.

Therefore, the presence of a lightning rod in a building does not mean that sensitive devices in the electrical installation are completely protected against overvoltages. Similarly, installing a surge arrester in the panel does not eliminate the need for an external lightning protection system for the structure. In an effective lightning protection approach, the external lightning protection system, grounding, equipotential bonding, and an appropriate SPD/surge arrester arrangement should be considered together.

Over time, the lightning rod installation may experience loose connections, corrosion, or changes in the grounding system. For this reason, during lightning rod measurement and periodic lightning rod inspection, the air termination, down conductors, test clamps, connections, and grounding system should be checked to assess the current status.

In short, lightning rods serve to safely conduct lightning current to the ground, while surge arresters limit overvoltages that may occur in the installation. They are not alternatives to each other, but rather complementary parts of a properly designed lightning and overvoltage protection system.