EN 50121-1:2017

Railway applications - Electromagnetic compatibility - Part 1: General

This European standard outlines the structure and the content of the whole set. It specifies the performance criteria applicable to the whole standards series. Clause 5 provides information about the EMC management. This part alone is not sufficient to give presumption of conformity to the essential requirements of the EMC-Directive and is intended to be used in conjunction with other parts of this standard. Annex A describes the characteristics of the railway system which affect electromagnetic compatibility (EMC) behaviour. Phenomena excluded from the set are Nuclear EM pulse, abnormal operating conditions (e.g. fault conditions) and the induction effects of direct lightning strike. Emission limits at the railway system boundary do not apply to intentional transmitters within the railway system boundaries. Safety considerations are not covered by this set of standards. The biological effects of non-ionizing radiation as well as apparatus for medical assistance, such as pacemakers, are not considered here.

Bahnanwendungen - Elektromagnetische Verträglichkeit - Teil 1: Allgemeines

Applications ferroviaires - Compatibilité électromagnétique - Partie 1: Généralités

Železniške naprave - Elektromagnetna združljivost - 1. del: Splošno

Ta evropski standard opisuje strukturo in vsebino celotnega sklopa. Določa merila zmogljivosti za celotno skupino standardov. Točka 5 podaja informacije o upravljanju elektromagnetne združljivosti.
Ta del sam ne zadostuje za domnevo o skladnosti z bistvenimi zahtevami Direktive o elektromagnetni združljivosti in ga je treba uporabljati v povezavi z drugimi deli tega standarda. V dodatku A so opisane značilnosti železniškega sistema, ki vplivajo na vedenje elektromagnetne združljivosti (EMC).
Pojavi, ki so izključeni iz sklopa, so jedrski elektromagnetni impulz, neobičajni obratovalni pogoji (npr. okvare) in induktivni učinki neposrednega udara strele.
Mejne vrednosti emisij na meji železniškega sistema se ne uporabljajo za namenske oddajnike v mejah železniškega sistema,
Ti standardi ne obravnavajo varnostnih napotkov.
Biološki učinki neionizirajočega sevanja in tudi aparati za medicinsko pomoč, kot so spodbujevalniki, v tem dokumentu niso obravnavani.

General Information

• Status: Published
• Publication Date: 12-Jan-2017
• ICS: 29.280 - Electric traction equipment
• ICS: 33.100.01 - Electromagnetic compatibility in general
• ICS: 45.020 - Railway engineering in general
• Technical Committee: CLC/TC 9X - Electrical and electronic applications for railways
• Drafting Committee: CLC/TC 9X - Electrical and electronic applications for railways
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 03-Nov-2021
• Completion Date: 23-Sep-2025
• Ref Project: SIST EN 50121-1:2017 - Railway applications - Electromagnetic compatibility - Part 1: General

Relations

• Replaces: EN 50121-1:2015 - Railway applications - Electromagnetic compatibility - Part 1: General
• Effective Date: 22-Jan-2023
• Revised: prEN 50121-1:2025 - Railway applications - Electromagnetic compatibility - Part 1: General
• Effective Date: 09-Apr-2024

Overview

EN 50121-1:2017 - Railway applications - Electromagnetic compatibility - Part 1: General defines the framework and performance criteria for the complete EN 50121 series on railway electromagnetic compatibility (EMC). It describes the structure and content of the set, the overall EMC performance criteria and management processes and provides an informative annex (Annex A) describing railway-system characteristics that affect EMC behaviour. This part alone does not give presumption of conformity with the EMC Directive and must be used together with the other EN 50121 parts.

Key topics and requirements

• Scope and exclusions: Covers EMC phenomena from DC to 400 GHz. Excludes nuclear electromagnetic pulse (EMP), abnormal operating (fault) conditions, direct lightning-strike induction effects, safety requirements and biological/non‑ionizing radiation effects (e.g., pacemakers).
• Performance criteria: Defines immunity performance levels based on EN 61000 principles - Criterion A (uninterrupted operation), Criterion B (post‑test operation, no loss of data), and Criterion C (temporary loss allowed if self‑recoverable).
• EMC management (Clause 5): Requires an early, formal EMC management plan for projects - identify sources and victims, analyse coupling mechanisms, and apply appropriate mitigation at subsystem and system boundaries.
• Annex A - Railway system characteristics: Describes principal electromagnetic phenomena and coupling mechanisms relevant to railways, including:
  • Conducted low‑frequency phenomena
  • Low‑frequency field phenomena
  • Conducted high‑frequency phenomena
  • Radiated high‑frequency phenomena
  • Electric traction system descriptions, components and internal/external noise sources
• Regulatory context: Emission limits at the railway system boundary exclude intentional transmitters located within railway boundaries. EN 50121-1 is a product‑family framework and takes precedence over generic standards where applicable.

Applications and who uses it

EN 50121-1:2017 is essential for:

• Rolling stock manufacturers and apparatus suppliers (to align equipment with railway EMC expectations)
• Infrastructure and project managers (to develop EMC management plans for lines, depots and stations)
• Signalling, telecommunications and power‑supply engineers (to ensure subsystem compatibility)
• EMC test laboratories and certification bodies (to interpret performance criteria and test reporting)
• System integrators and procurement teams (to specify EMC requirements and assess fit‑for‑purpose)

Practical uses include preparing EMC plans, defining emission/immunity requirements for equipment and subsystems, assessing interference risks at interfaces, and guiding mitigation measures in challenging environments or “special locations.”

Related standards

• EN 50121-2: Emission of the whole railway system to the outside world
• EN 50121-3-1 / 3-2: Rolling stock - Train and apparatus requirements
• EN 50121-4: Signalling and telecommunications apparatus
• EN 50121-5: Fixed power supply installations and apparatus
• EN 61000 series: General EMC guidance and test methods

Keywords: EN 50121-1:2017, railway electromagnetic compatibility, railway EMC standards, EMC management, emission limits, immunity levels, EN 50121 series.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2017
1DGRPHãþD
SIST EN 50121-1:2015
Železniške naprave - Elektromagnetna združljivost - 1. del: Splošno
Railway applications - Electromagnetic compatibility - Part 1: General
Bahnanwendungen - Elektromagnetische Verträglichkeit - Teil 1: Allgemeines
Applications ferroviaires - Compatibilité électromagnétique - Partie 1: Généralités
Ta slovenski standard je istoveten z: EN 50121-1:2017
ICS:
33.100.01 Elektromagnetna združljivost Electromagnetic compatibility
na splošno in general
45.020 Železniška tehnika na Railway engineering in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 50121-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2017
ICS 29.280; 45.020; 33.100.01 Supersedes EN 50121-1:2015
English Version
Railway applications - Electromagnetic compatibility - Part 1:
General
Applications ferroviaires - Compatibilité électromagnétique - Bahnanwendungen - Elektromagnetische Verträglichkeit -
Partie 1: Généralités Teil 1: Allgemeines
This European Standard was approved by CENELEC on 2016-11-07. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any
alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50121-1:2017 E
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Abbreviations . 6
4 Performance criteria . 7
5 Management of EMC . 7
Annex A (informative) The railway system . 8
A.1 Introduction . 8
A.2 General coupling mechanisms . 8
A.3 Principal electromagnetic phenomena for immunity . 9
A.3.1 Conducted low frequency phenomena . 9
A.3.2 Low frequency field phenomena . 9
A.3.3 Conducted high frequency phenomena . 9
A.3.4 Radiated high frequency phenomena . 9
A.4 Principal electromagnetic phenomena for emission . 9
A.5 Description of the different electric traction systems . 9
A.6 Components of electric traction systems . 10
A.7 Internal sources of electromagnetic noise . 10
A.7.1 General . 10
A.8 Summary of main characteristics of railway systems . 12
A.9 External sources of disturbance . 12
Bibliography . 13

European foreword
This document (EN 50121-1:2017) has been prepared by CLC/TC 9X, “Electrical and electronic
applications for railways”.
The following dates are fixed:
• latest date by which this document has to be implemented at (dop) [2017-11-07]
national level by publication of an identical national standard
or by endorsement
• latest date by which the national standards conflicting with (dow) [2019-11-07]
this document have to be withdrawn
This document supersedes EN 50121-1:2015.
EN 50121-1:2015:
— deletion of Annex ZZ.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
EN 50121, Railway applications — Electromagnetic compatibility, consists of the following parts:
— Part 1: General [the present document];
— Part 2: Emission of the whole railway system to the outside world;
— Part 3-1: Rolling stock — Train and complete vehicle;
— Part 3-2: Rolling stock — Apparatus;
— Part 4: Emission and immunity of the signalling and telecommunications apparatus;
— Part 5: Emission and immunity of fixed power supply installations and apparatus.

Introduction
The railway system EMC set of product-specific European Standards is intended, in the main, to permit
compliance with the EMC Directive, but also to provide a means of prescribing compatibility between
internal parts of the railway system. It consists of five parts described at the end of this Introduction.
The set of standards provides both a framework for managing the EMC for railway systems and also
specifies the limits for the electromagnetic (EM) emission of the railway system as a whole to the
outside world and for the EM emission and immunity for equipment operating within the railway system.
The latter is intended to be compatible with the emission limits set for the railway system as a whole
and also provides for establishing confidence in equipment being Fit For Purpose in the Railway
environment. There are different stationary emission limits set for trams/trolleybuses and for
metro/mainline railway systems. The frequency covered by the standards is in the range from DC to
400 GHz. No measurements need to be performed at frequencies where no requirement is specified.
The limits for EMC phenomena are set so that the railway system as a whole satisfies the Directive on
electromagnetic compatibility with the outside world, and so that EMC is achieved between the various
parts of the railway system. Any specific problems in complying with the limits are intended to be
addressed by the procedures given in the EMC Directive. Throughout the set of standards, the
immunity levels are chosen to ensure a reasonable level of EMC with other apparatus within the local
railway environment and with emissions which enter the railway system from the outside world. Limits
are also placed on EM emission by railway systems into the outside world.
The compatibility between railway system emissions and their external environment is based upon
emission limits from the railway systems being set by considering the results from measurements at
the time that the EMC Directive became enforceable. Given that the general compatibility between
railway systems and their environment was satisfactory at the time these measurements were made
and subsequent experience of applying the limits has confirmed their acceptability, compliance with
this Standard has been judged to give satisfactory compatibility. The immunity and emission levels do
not of themselves guarantee that the railway system will have satisfactory compliance with its
neighbours. In exceptional circumstances, for instance near a “special location” which has unusually
high levels of EM interference, the railway system may require additional measures to be taken to
ensure proper compatibility. Particular care should be taken when in proximity to equipment not
covered by the EMC Directive such as radio transmission equipment, military or medical installations.
Attention is particularly drawn to any magnetic imaging equipment in hospitals that may be near to
urban transport. In all these cases, compatibility should be achieved with consultation and co-operation
between the interested parties.
The immunity and emission levels themselves do not guarantee that integration of the apparatus within
the railway system will necessarily be satisfactory. The standard cannot cover all the possible
configurations of apparatus, but the test levels are sufficient to achieve satisfactory EMC in the majority
of cases. In exceptional circumstances, for instance near a “special location” which has unusually high
levels of EM interference, the system may require additional measures to be taken to ensure proper
operation. The resolution of this is a matter for discussion between the equipment supplier and the
project manager, infrastructure manager or equivalent.
The railway apparatus is assembled into large systems and installations, such as trains and signalling
control centres. Details are given in Annex A. It is not, therefore, possible to establish immunity tests
and limits for these large assemblies. The immunity levels for the apparatus will normally ensure
reliable operation, but it is important to prepare an EMC management plan to deal with complex
situations or to deal with specific circumstances; for example, the passage of the railway line close to a
high power radio-transmitter which produces abnormally high field strengths. Special conditions may
have to be applied for railway equipment which has to work near such a transmitter and these will be
accepted as National Conditions for the specification.

The series of standards EN 50121, Railway applications — Electromagnetic compatibility, contains the
following parts:
— Part 1: General: This part gives a description of the electromagnetic behaviour of a railway
system; it specifies the performance criteria for the whole set. A management process to achieve
EMC at the interface between the railway infrastructure and trains is referenced.
— Part 2: Emission of the whole railway system to the outside world: This part sets the
emission limits from the railway system to the outside world at radio frequencies. It defines the
applied test methods and gives information on typical field strength values at traction and radio
frequency (cartography).
— Part 3-1: Rolling stock — Train and complete vehicle: This part specifies the emission and
immunity requirements for all types of rolling stock. It covers traction rolling stock and trainsets, as
well as independent hauled rolling stock. The scope of this part of the series ends at the interface
of the rolling stock with its respective energy inputs and outputs.
— Part 3-2: Rolling stock — Apparatus: This part applies to emission and immunity aspects of
EMC for electrical and electronic apparatus intended for use on railway rolling stock. It is also used
as a means of dealing with the impracticality of immunity testing a complete vehicle.
— Part 4: Emission and immunity of the signalling and telecommunications apparatus: This
part specifies limits for electromagnetic emission and immunity for signalling and
telecommunications apparatus installed within a Railway system. The EMC plan needs to state, if
this part is also applicable for railway operational equipment mounted trackside or at platforms.
— Part 5: Emission and immunity of fixed power supply installations and apparatus: This part
applies to emission and immunity aspects of EMC for electrical and electronic apparatus and
components intended for use in railway fixed installations associated with power supply.
EN 50121-1 and EN 50121-2 are product family standards which take precedence over generic
standards.
EN 50121-3-1, EN 50121-3-2, EN 50121-4, and EN 50121-5 are product standards.

1 Scope
This European standard outlines the structure and the content of the whole set.
It specifies the performance criteria applicable to the whole standards series.
Clause 5 provides information about the EMC management.
This part alone is not sufficient to give presumption of conformity to the essential requirements of the
EMC-Directive and is intended to be used in conjunction with other parts of this standard.
Annex A describes the characteristics of the railway system which affect electromagnetic compatibility
(EMC) behaviour.
Phenomena excluded from the set are Nuclear EM pulse, abnormal operating conditions (e.g. fault
conditions) and the induction effects of direct lightning strike.
Emission limits at the railway system boundary do not apply to intentional transmitters within the railway
system boundaries.
Safety considerations are not covered by this set of standards.
The biological effects of non-ionizing radiation as well as apparatus for medical assistance, such as
pacemakers, are not considered here.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 50121 (all parts), Railway applications — Electromagnetic compatibility
EN 61000 (all parts), Electromagnetic compatibility (EMC) (IEC 61000 series)
3 Abbreviations
AC alternating current
DC direct
...