EMC Standards in Railways

Other languages:

New standards and new regulations have streamlined the process of demonstrating conformance with the EMC Directive for apparatus in the railway environment.

Three events have transpired to bring about this streamlining:

EN 50121

The European Standard EN 50121 relating to railways has five parts.

Whilst the scope of the standards cover the frequency range DC to 400GHz, emission limits are not set above 1GHz. Immunity levels are specified up to 2.5 GHz (increased from 1 GHz in the 2000 version).

Apparatus in the Railway Environment

Apparatus for use on-board trains (Part 3-2), signalling & telecommunications equipment (Part 4) and power supply apparatus (Part 5) can now be declared to comply with the EMC directive, for the railway environment, by applying the appropriate Part of EN 50121 – this now provides a presumption of conformity.

Suppliers of apparatus for railway environments may, however, be contractually required to provide specific documentation regarding EMC, due to the requirements for fixed installations.

Fixed Installations

New installations in the railway environment (or modifications) are regarded as fixed installations; while exempt from CE marking and Declarations, there are explicit requirements for the "Responsible Person" of the installation to compile and maintain documentation sufficient to demonstrate the compliance of the installation with the essential requirements of the EMC directive.

EN 50121 provides overall emission limits (Part 2) and per-train emission limits (Part 3-1). It also requires an EMC management plan to be produced and followed. Such a management plan should minimise or remove problems due to incompatibility, and should provide the necessary documentation for the Responsible Person.

NB: in the UK, requirements of the organisations owning and operating infrastructure and services may not fully match the above requirements.

Last updated: 2007-Sep-28