prEN 50121-5:2025

Scope

This document applies to electrical and electronic apparatus and systems intended for use in railway fixed installations for power supply with railway function (e.g. not covered are equipment such as fire detection devices installed inside substations, room access devices, air conditioning, lighting systems, etc.). This includes the power feed to the apparatus, the apparatus itself with its protective control circuits, trackside items such as switching stations, power substations for charging of battery on the board of train (auxiliary charging points), power autotransformers, booster transformers, substation power switchgear and power switchgear to other longitudinal and local supplies. Emission and immunity limits are given for apparatus which are situated: a) within the boundary of a substation which delivers electric power to a railway; b) beside the track for the purpose of controlling or regulating the railway power supply, including power factor correction; c) along the track for the purpose of supplying electrical power to the railway other than by means of the conductors used for contact current collection, and associated return conductors. Included are high voltage feeder systems within the boundary of the railway which supply substations at which the voltage is reduced to the railway system voltage; d) beside the track for controlling or regulating electric power supplies to ancillary railway uses. This category includes power supplies to marshalling yards, maintenance depots and stations; e) various other non-traction power supplies from railway sources which are shared with railway traction. Note: Filters operating at railway system voltage (for example, for harmonic suppression or power factor correction) are not included in this standard since each site has special requirements. Filters would normally have separate enclosures with separate rules for access. If electromagnetic limits are required, these will appear in the specification for the equipment. This document specifies limits for emission and immunity and provides performance criteria. The standard does not specify basic personal safety requirements for apparatus such as protection against electric shock, unsafe operation, insulation co-ordination and related dielectric tests. The requirements were developed for and are applicable to this set of apparatus when operating under normal conditions. Fault conditions of the apparatus have not been taken into account. The test frequency range defined in this document is considered to ensure the electromagnetic compatibility of the apparatus in the whole frequency range from 0 Hz (DC) to 400 GHz.