This European Standard applies to emission and immunity aspects of EMC for electrical and electronic
apparatus intended for use on railway rolling stock. EN 50121-3-2 applies for the integration of
apparatus on rolling stock.
The frequency range considered is from DC to 400 GHz. No measurements need to be performed at
frequencies where no requirement is specified.
The application of tests shall depend on the particular apparatus, its configuration, its ports, its
technology and its operating conditions.
This standard takes into account the internal environment of the railway rolling stock and the external
environment of the railway, and interference to the apparatus from equipment such as hand-held radio-
If a port is intended to transmit or receive for the purpose of radio communication (intentional radiators,
e.g. transponder systems), then the radiated emission requirement in this standard is not intended to
be applicable to the intentional transmission from a radio-transmitter as defined by the ITU.
Immunity limits do not apply in the exclusion bands as defined in the corresponding EMC related
standard for radio equipment.
This standard does not apply to transient emissions when starting or stopping the apparatus.
The objective of this standard is to define limits and test methods for electromagnetic emissions and
immunity test requirements in relation to conducted and radiated disturbances.
These limits and tests represent essential electromagnetic compatibility requirements.
Emission requirements have been selected so as to ensure that disturbances generated by the
apparatus operated normally on railway rolling stock do not exceed a level which could prevent other
apparatus from operating as intended. The emission limits given in this standard take precedence over
emission requirements for individual apparatus on board the rolling stock given in other standards.
Likewise, the immunity requirements have been selected so as to ensure an adequate level of
immunity for rolling stock apparatus.
The levels do not however cover all cases which may occur with an extremely low probability of
occurrence in any location. Specific requirements which deviate from this standard shall be specified.
Test requirements are specified for each port considered.
These specific provisions are to be used in conjunction with the general provisions in EN 50121-1.
Directives related to this standard.
Directive 2014/30/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to electromagnetic compatibility (recast)