This European Standard gives particular requirements for voltage transformers used in a.c. single-phase railway applications, fixed installations. This European standard refers to single-phase inductive voltage transformers for railway applications on 15 kV, 16 ? Hz and 25 kV, 50 Hz overhead lines, these voltages and frequencies being defined in accordance with EN 50163. The main uses of these voltage transformers are: ? voltage indication; ? measurement; ? protection.