A method and device for protecting an electric system against overvoltage occurrences, the electric system being adapted to be subjected to voltages. The device includes a plurality of surge arresters and a detector configured to detect overvoltage occurrences in the electric system. The surge arresters are connected in series, the plurality of surge arresters including a first surge arrester which is connectable to ground and a second surge arrester which is connectable to the electric system which is to be protected. The device includes a switch connected in parallel with at least one surge arrester of the plurality of surge arresters, and the switch is adapted to be open when no overvoltage occurrence is detected and adapted to close upon overvoltage occurrence detection and short-circuit the surge arrester with which it is connected in parallel. An electric system includes at least one such device.