This EN 50152-1 is applicable to single-pole and two-pole alternating current (a.c.) circuit-breakers which are:- for indoor or outdoor fixed installations in tractions systems, and- operated with an a.c. line voltage and frequency as specified in EN 50163.NOTE 1 EN 50163 specifies the a.c. traction systems 15 kV 16,7 Hz and 25 kV 50 Hz.NOTE 2 As rails of a.c. traction systems are connected to earth and included in the return current path all phase to earth voltages will be within the tolerances as specified in EN 50163. Nevertheless phase to phase voltages are sometimes higher e.g. in autotransformer systems.This European Standard is also applicable to the operating devices of circuit-breakers and to their auxiliary equipment.This European Standard does not address circuit-breakers with dependent manual operating mechanism.NOTE 3 It is impossible to specify a rated short-circuit making current for these circuit-breakers and it is likely that such dependent manual operation is not meeting safety considerations.