This Application Guide supports the European Standards EN 50526 1 and EN 50526 2. Guidance is offered on the following subjects. –The selection and installation of surge arresters –The selection and installation of voltage limiting devices as VLD-O and VLD-F. –The arrangement of the surge arresters and VLDs Because of differences in the established, proven methods, electric traction systems of nominal voltage 600 V – 750 V are treated separately from the systems at higher nominal voltages. This application guide does not treat systems different from the d.c. electrified traction systems