EN 50121-4:2016
(Main)Railway applications - Electromagnetic compatibility - Part 4: Emission and immunity of the signalling and telecommunications apparatus
General Information
- Abstract
This European Standard applies to signalling and telecommunication apparatus that is installed inside the railway environment. Signalling and telecommunication apparatus mounted in vehicles is covered by FprEN 50121 3 2:2016, signalling and telecommunication apparatus installed inside the substation and connected to substation equipment is covered by FprEN 50121 5:2016. This European Standard specifies limits for emission and immunity and provides performance criteria for signalling and telecommunications (S&T) apparatus (including power supply systems belonging to S&T) which may interfere with other apparatus inside the railway environment, or increase the total emissions for the railway environment and so risk causing Electro-Magnetic Interference (EMI) to apparatus outside the railway system. The requirements specified given in this standard apply for: — vital equipment such as interlocking or command and control; — apparatus inside the 3 m zone; — ports of apparatus inside the 10 m zone with connection inside the 3 m zone; — ports of apparatus inside the 10 m zone with cable length > 30 m. Other apparatus not covered by at least one of these given cases should be in compliance with EN 61000 6 2. 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 are 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. 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 frequency range considered is from DC to 400 GHz. No measurements need to be performed at frequencies where no requirement is specified. For products in the scope of EN 61000 3 2, EN 61000 3 3, EN 61000 3 11 or EN 61000 3 12 the requirements of those standards also apply. These specific provisions are to be used in conjunction with the general provisions in FprEN 50121 1:2016. The immunity and emission levels do not of themselves guarantee that the integration of apparatus will necessarily be satisfactory. The standard cannot cover all the possible configurations of the apparatus, but the test levels are sufficient to achieve satisfactory EMC in the majority of cases.
- Status
- Published
- Publication Date
- 22-Dec-2016
- Withdrawal Date
- 23-Oct-2019
- 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
- 16-Oct-2024
- Completion Date
- 25-Aug-2026
- Directive
- Harmonized Standard2014/30/EU - 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)OJ Ref: C 246/01 OJ Date: 13-Jul-2018
Overview
EN 50121-4:2016 - Railway applications - Electromagnetic compatibility - Part 4: Emission and immunity of the signalling and telecommunications apparatus - is a CLC (CENELEC) product standard that defines electromagnetic compatibility (EMC) requirements for signalling and telecommunication (S&T) equipment installed inside the railway environment. It sets emission and immunity limits and performance criteria to prevent Electro-Magnetic Interference (EMI) within the railway and to limit emissions that could affect equipment outside the railway system. The frequency range considered is from DC up to 400 GHz.
Key topics and requirements
Scope and applicability
- Applies to fixed S&T apparatus inside the railway environment (vehicle-mounted S&T is covered by EN 50121-3-2; substation-connected S&T by EN 50121-5).
- Targets vital equipment (e.g., interlocking, command & control), apparatus within the 3 m zone, ports in the 10 m zone connected into the 3 m zone, and ports with cables > 30 m.
- Other apparatus should comply with EN 61000-6-2 where not covered.
Emission requirements
- Emission requirements align with EN 61000-6-4; compliance with EN 61000-6-4 is deemed acceptable when DC power port emissions meet AC port limits.
- Conducted emission limits apply to both AC and DC power ports (see Table 1 in the standard).
Immunity requirements and performance criteria
- Port-by-port immunity testing based on basic EMC test standards (EN 61000‑4‑x series, EN 55016-2-1).
- Performance criteria follow the levels defined in EN 50121-1.
- Typical immunity tests include RF radiated field (e.g., 10 V/m, 20 V/m bands), electrostatic discharge (±6 kV contact / ±8 kV air), power-frequency magnetic field tests, surge and fast transient/burst tests.
Exemptions and limits
- Intentional radio transmitters (e.g., transponders) are not subject to the radiated emission requirements of this standard - they follow radio/ITU regulations and relevant EMC radio equipment standards.
- Immunity limits do not apply in radio exclusion bands defined in radio EMC standards.
- The standard does not cover basic personal safety (electric shock, insulation tests) or fault-condition behavior.
Practical applications - who uses it
- Signalling and telecom equipment manufacturers - design and EMC test criteria for S&T products.
- Railway system integrators and infrastructure owners - ensure equipment integration to prevent EMI and meet EMC acceptance.
- EMC test laboratories - perform port-by-port emission and immunity testing to the specified EN 61000 and EN 50121-4 methods.
- Safety and compliance engineers - verify that vital signalling systems meet EMC performance criteria under normal operating conditions.
Related standards
- EN 50121-1 (General provisions)
- EN 50121-3-2 (Rolling stock - apparatus)
- EN 50121-5 (Fixed power supply installations)
- EN 61000-6-4, EN 61000-6-2 (Generic emission/immunity)
- EN 61000-4-x series, EN 55016-2-1 (Basic test methods)
EN 50121-4:2016 is essential for achieving robust EMC for signalling and telecommunications equipment in railways, ensuring reliable operation and minimizing EMI risks during system integration.
Relations
- Effective Date
- 19-Jan-2016
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 03-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
- Effective Date
- 09-Feb-2026
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Frequently Asked Questions
EN 50121-4:2016 is a standard published by CLC. Its full title is "Railway applications - Electromagnetic compatibility - Part 4: Emission and immunity of the signalling and telecommunications apparatus". This standard covers: This European Standard applies to signalling and telecommunication apparatus that is installed inside the railway environment. Signalling and telecommunication apparatus mounted in vehicles is covered by FprEN 50121 3 2:2016, signalling and telecommunication apparatus installed inside the substation and connected to substation equipment is covered by FprEN 50121 5:2016. This European Standard specifies limits for emission and immunity and provides performance criteria for signalling and telecommunications (S&T) apparatus (including power supply systems belonging to S&T) which may interfere with other apparatus inside the railway environment, or increase the total emissions for the railway environment and so risk causing Electro-Magnetic Interference (EMI) to apparatus outside the railway system. The requirements specified given in this standard apply for: — vital equipment such as interlocking or command and control; — apparatus inside the 3 m zone; — ports of apparatus inside the 10 m zone with connection inside the 3 m zone; — ports of apparatus inside the 10 m zone with cable length > 30 m. Other apparatus not covered by at least one of these given cases should be in compliance with EN 61000 6 2. 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 are 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. 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 frequency range considered is from DC to 400 GHz. No measurements need to be performed at frequencies where no requirement is specified. For products in the scope of EN 61000 3 2, EN 61000 3 3, EN 61000 3 11 or EN 61000 3 12 the requirements of those standards also apply. These specific provisions are to be used in conjunction with the general provisions in FprEN 50121 1:2016. The immunity and emission levels do not of themselves guarantee that the integration of apparatus will necessarily be satisfactory. The standard cannot cover all the possible configurations of the apparatus, but the test levels are sufficient to achieve satisfactory EMC in the majority of cases.
This European Standard applies to signalling and telecommunication apparatus that is installed inside the railway environment. Signalling and telecommunication apparatus mounted in vehicles is covered by FprEN 50121 3 2:2016, signalling and telecommunication apparatus installed inside the substation and connected to substation equipment is covered by FprEN 50121 5:2016. This European Standard specifies limits for emission and immunity and provides performance criteria for signalling and telecommunications (S&T) apparatus (including power supply systems belonging to S&T) which may interfere with other apparatus inside the railway environment, or increase the total emissions for the railway environment and so risk causing Electro-Magnetic Interference (EMI) to apparatus outside the railway system. The requirements specified given in this standard apply for: — vital equipment such as interlocking or command and control; — apparatus inside the 3 m zone; — ports of apparatus inside the 10 m zone with connection inside the 3 m zone; — ports of apparatus inside the 10 m zone with cable length > 30 m. Other apparatus not covered by at least one of these given cases should be in compliance with EN 61000 6 2. 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 are 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. 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 frequency range considered is from DC to 400 GHz. No measurements need to be performed at frequencies where no requirement is specified. For products in the scope of EN 61000 3 2, EN 61000 3 3, EN 61000 3 11 or EN 61000 3 12 the requirements of those standards also apply. These specific provisions are to be used in conjunction with the general provisions in FprEN 50121 1:2016. The immunity and emission levels do not of themselves guarantee that the integration of apparatus will necessarily be satisfactory. The standard cannot cover all the possible configurations of the apparatus, but the test levels are sufficient to achieve satisfactory EMC in the majority of cases.
EN 50121-4:2016 is classified under the following ICS (International Classification for Standards) categories: 29.280 - Electric traction equipment; 33.100.01 - Electromagnetic compatibility in general; 45.020 - Railway engineering in general. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 50121-4:2016 has the following relationships with other standards: It is inter standard links to EN 50121-4:2015, EN 61000-4-8:2010, EN 61000-6-4:2007, EN 55016-2-1:2014, EN 61000-4-6:2014, EN 61000-4-3:2006, EN 61000-4-4:2012, EN 61000-6-2:2005, EN 61000-4-5:2014, EN 61000-4-2:2009, EN 15437-1:2009+A1:2022, EN 15654-1:2018, EN 16704-2-1:2016, EN 17168:2021, CEN/TS 15427-1-2:2021. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 50121-4:2016 is associated with the following European legislation: EU Directives/Regulations: 2014/30/EU; Standardization Mandates: M/404. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN 50121-4:2016 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-2017
1DGRPHãþD
SIST EN 50121-4:2015
Železniške naprave - Elektromagnetna združljivost - 4. del: Sevanje in odpornost
signalnih in telekomunikacijskih naprav
Railway applications - Electromagnetic compatibility - Part 4: Emission and immunity of
the signalling and telecommunications apparatus
Bahnanwendungen - Elektromagnetische Verträglichkeit - Teil 4: Störaussendungen und
Störfestigkeit von Signal- und Telekommunikationseinrichtungen
Applications ferroviaires - Compatibilité électromagnétique - Partie 4: Emission et
immunité des appareils de signalisation et de télécommunication
Ta slovenski standard je istoveten z: EN 50121-4:2016
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 50121-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2016
ICS 29.280; 33.100.01; 45.020 Supersedes EN 50121-4:2015
English Version
Railway applications - Electromagnetic compatibility - Part 4:
Emission and immunity of the signalling and telecommunications
apparatus
Applications ferroviaires - Compatibilité électromagnétique - Bahnanwendungen - Elektromagnetische Verträglichkeit -
Partie 4: Emission et immunité des appareils de Teil 4: Störaussendungen und Störfestigkeit von Signal-
signalisation et de télécommunication und Telekommunikationseinrichtungen
This European Standard was approved by CENELEC on 2016-10-24. 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, 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
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50121-4:2016 E
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviations . 6
3.1 Terms and definitions . 6
3.2 Abbreviations . 7
4 Description of location . 7
5 Emission limits for apparatus . 7
6 Immunity. 9
6.1 Performance criteria. 9
6.2 Immunity requirements . 9
Annex ZZ (informative) Relationship between this European Standard and the essential
requirements of Directive 2014/30/EU [2014 OJ L96] aimed to be covered . 16
Bibliography . 17
European foreword
This document (EN 50121-4:2016) 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 (dop) 2017-07-24
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2019-10-24
conflicting with this document have to
be withdrawn
This document supersedes EN 50121-4:2015.
EN 50121-4:2006:
— clarification of scope (Clause 1);
— set dated normative references (Clause 2);
— new definition (Clause 3);
— emission requirement extended in the frequency range 1 GHz to 6 GHz following EN 61000-6-4;
— immunity requirement extended in the frequency range 5,1 GHz to 6 GHz;
— revision of Annex ZZ.
This European Standard is to be read in conjunction with EN 50121-1.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZZ, which is an integral part of this
document.
This standard forms Part 4 of the European Standard series EN 50121, published under the general
title “Railway applications - Electromagnetic compatibility”. The series consists of:
— Part 1: General;
— 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
This European Standard has been prepared in the form of a Product Standard.
It defines the immunity and emission test requirements for apparatus defined in the scope in relation to
the electromagnetic disturbances likely to be experienced in the railway. In particular, the test
requirements represent the essential electromagnetic immunity requirements and have been selected
to ensure an adequate level of immunity for apparatus installed on the railway locations.
Test requirements are specified for each port considered.
Safety considerations are not covered by this standard.
In specific situations, where the level of disturbances may exceed the levels considered in this
standard, e.g. at a special location or where a hand-held transmitter is used in very close proximity to
an apparatus, special mitigation measures may have to be employed.
1 Scope
This European Standard applies to signalling and telecommunication apparatus that is installed inside
the railway environment. Signalling and telecommunication apparatus mounted in vehicles is covered
by EN 50121-3-2:2016, signalling and telecommunication apparatus installed inside the substation and
connected to substation equipment is covered by EN 50121-5:2016.
This European Standard specifies limits for emission and immunity and provides performance criteria
for signalling and telecommunications (S&T) apparatus (including power supply systems belonging to
S&T) which may interfere with other apparatus inside the railway environment, or increase the total
emissions for the railway environment and so risk causing Electro-Magnetic Interference (EMI) to
apparatus outside the railway system.
The requirements specified in this standard apply for:
— vital equipment such as interlocking or command and control;
— apparatus inside the 3 m zone;
— ports of apparatus inside the 10 m zone with connection inside the 3 m zone;
— ports of apparatus inside the 10 m zone with cable length > 30 m.
Other apparatus not covered by at least one of these given cases should be in compliance with
EN 61000-6-2.
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 are 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.
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 frequency range considered is from DC to 400 GHz. No measurements need to be performed at
frequencies where no requirement is specified.
For products in the scope of EN 61000-3-2, EN 61000-3-3, EN 61000-3-11 or EN 61000-3-12 the
requirements of those standards also apply.
These specific provisions are to be used in conjunction with the general provisions in
EN 50121-1:2016.
The immunity and emission levels do not of themselves guarantee that the integration of apparatus will
necessarily be satisfactory. The standard cannot cover all the possible configurations of the apparatus,
but the test levels are sufficient to achieve satisfactory EMC in the majority of cases.
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 50121-1:2017, Railway applications — Electromagnetic compatibility — Part 1: General
EN 55016-2-1:2014, Specification for radio disturbance and immunity measuring apparatus and
methods — Part 2-1: Methods of measurement of disturbances and immunity — Conducted
disturbance measurements (CISPR 16-2-1:2014)
EN 61000-4-2:2009, Electromagnetic compatibility (EMC) — Part 4-2: Testing and measurement
techniques — Electrostatic discharge immunity test (IEC 61000-4-2:2008)
EN 61000-4-3:2006, Electromagnetic compatibility (EMC) — Part 4-3: Testing and measurement
techniques — Radiated, radio-frequency, electromagnetic field immunity test (IEC 61000-4-3:2006)
EN 61000-4-4:2012, Electromagnetic compatibility (EMC) — Part 4-4: Testing and measurement
techniques — Electrical fast transient/burst immunity test (IEC 61000-4-4:2012)
EN 61000-4-5:2014, Electromagnetic compatibility (EMC) — Part 4-5: Testing and measurement
techniques — Surge immunity test (IEC 61000-4-5:2014)
EN 61000-4-6:2014, Electromagnetic compatibility (EMC) — Part 4-6: Testing and measurement
techniques — Immunity to conducted disturbances, induced by radio-frequency fields (IEC 61000-4-
6:2013)
EN 61000-4-8:2010, Electromagnetic compatibility (EMC) — Part 4-8: Testing and measurement
techniques — Power frequency magnetic field immunity test (IEC 61000-4-8:2009)
EN 61000-6-2:2005, Electromagnetic compatibility (EMC) — Part 6-2: Generic standards — Immunity
for industrial environments (IEC 61000-6-2:2005)
EN 61000-6-4:2007 , Electromagnetic compatibility (EMC) — Part 6-4: Generic standards — Emission
standard for industrial environments (IEC 61000-6-4:2006)
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
port
particular interface of the specified apparatus with the external environment
EXAMPLE AC power port, DC power port, I/O (input/output) port, earth port.
[SOURCE: IEC 60050-821: CDV2015, 821-11-36]
3.1.2
enclosure port
physical boundary of the apparatus through which electromagnetic fields may radiate or impinge
Enclosure port
AC power port I/O port
DC po
...