Various types of surge voltages occur in electrical plants and electronic systems. Depending on the cause, the duration and amplitude of each surge can vary greatly. The direct or indirect consequences of lightning strikes are one particular cause of surge voltages. Here, during the surge voltage, high surge currents with amplitudes of up to ten thousand amperes can occur. In this case, largescale equipment failures and data loss can occur. This failure is often not covered by insurance and, within a short period of time, can become a heavy financial burden – especially in comparison to the cost of installing a Surge Protection Device (SPD).