SIST-TS CLC/TS 50711:2026
(Main)Railway applications - Fixed installations - High-voltage/low-voltage prefabricated substations in AC and DC electric traction systems
- Abstract
This document specifies
- the service conditions;
- rated characteristics;
- general structural requirements; and
- test methods
of prefabricated traction substations for use in AC and DC electric traction systems, which as a minimum contain an enclosure and a traction switchgear designed and manufactured according to
- EN 50123 6 in DC electric traction systems;
- CLC/TS 50152 4 in AC electric traction systems.
Traction substations using non-type tested traction switchgear are covered by EN IEC 61936 1:2021.
NOTE 1 Due to the type testing requirements on the prefabricated traction substations only type tested traction switchgear is considered.
The enclosures of the prefabricated traction substations for use in AC and DC electric traction systems are
- designed for outdoor installation at locations with or without public accessibility;
- connected by insulated cable;
- operated from inside (walk-in type) or outside (non-walk-in type).
NOTE 2 Prefabricated traction substations for railway applications are typically of the walk-in type due to the rating and resulting dimensions of the AC or DC traction switchgear.
Prefabricated traction substations can be situated at ground level or partially or completely below ground level.
In general a prefabricated traction substation comprises an enclosure, a traction switchgear and can include the following additional main components:
- power transformers;
- electronic power converters;
- high-voltage and/or low-voltage switchgear and controlgear;
- high-voltage and/or low-voltage interconnections;
- auxiliary equipment and circuits.
However, relevant provisions of this document are applicable to designs where not all these main components exist.
NOTE 3 The term "main component”"is defined in 3.3.103 of EN IEC 62271 202:2022.
NOTE 4 For example, a switching station in an AC electric traction system consisting of an AC metal-enclosed traction switchgear and auxiliary circuits only.
NOTE 5 EN IEC 61936 1:2021 provides general rules for the design and erection of high-voltage power installations. As well, it specifies additional requirements for the external connections, erection and operation at the place of installation of high-voltage prefabricated traction substations compliant with EN IEC 62271 202:2022, which are regarded as a main component of such installation. Non-prefabricated traction substations, are generally covered by EN IEC 61936 1:2021.
This document covers designs using natural ventilation and/or any other kind of cooling system.
Due to the large number of different main components being addressed in this document the expression "main components shall comply with (the applicable subclause of) their specific product standard" is used in this document. This means that reference is to
- EN 50123 6:2003 for DC traction switchgear;
- to other parts of the EN 50123 series for switching devices also measurement, control and protection devices for DC traction applications;
- CLC/TS 50152 4:2021 for AC traction switchgear;
- other parts of the EN 50152 series for switching devices and also measurement, control and protection devices for AC traction applications;
- EN 50328:2003 for electronic power converters;
- EN 50329:2003 for traction power transformers;
- EN IEC 61439-1:2021 for low-voltage non-traction switchgear; and
- EN IEC 62271 200:2021 for high-voltage non-traction switchgear.
- Status
- Published
- Publication Date
- 01-Sep-2026
- Technical Committee
- ŽEN - Electrical applications for railways
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 09-Jun-2026
- Due Date
- 14-Aug-2026
- Completion Date
- 02-Sep-2026
SIST-TS CLC/TS 50711:2026 is a CENELEC Technical Specification for railway fixed installations. It specifies the service conditions, ratings, design rules, and test methods for high-voltage/low-voltage prefabricated substations used in AC and DC electric traction systems, so manufacturers, specifiers, and buyers can describe, build, test, and accept these assemblies in a consistent way.
What does SIST-TS CLC/TS 50711:2026 specify?
SIST-TS CLC/TS 50711:2026 covers prefabricated traction substations that include, at minimum, an enclosure and traction switchgear designed to the relevant railway product standards. It is aimed at outdoor substations, with or without public accessibility, connected by insulated cable and operated from inside or outside the enclosure.
The document also covers substations at ground level or partly or fully below ground level, and it allows additional main components such as power transformers, electronic power converters, high-voltage and low-voltage switchgear, interconnections, and auxiliary equipment. The document is organized into Clauses 1 to 13, followed by four annexes and a bibliography.
| Annex | What it covers |
|---|---|
| Annex A | Normative method to verify Internal Arc Classification (IAC) |
| Annex B | Normative test to verify sound level |
| Annex C | Informative examples of earthing circuits |
| Annex D | Informative method of evaluating the thermal performance of enclosures |
What are the key requirements of SIST-TS CLC/TS 50711:2026?
SIST-TS CLC/TS 50711:2026 is built around railway traction service conditions, enclosure thermal performance, internal arc protection, and type and routine testing. In practice, it tells you what the assembly must be designed for, what must be declared on the nameplate, and what must be verified before delivery and after site assembly.
Service conditions and ratings
Clause 4 sets normal and special service conditions. For special service conditions, the purchaser and supplier need to agree the selection, with EN 50125-2 used as guidance. This matters because railway sites can vary widely in altitude, temperature, vibration, and other environmental stresses.
Clause 5 defines the assembly by its traction-system nominal voltage, rated frequency, rated power, rated class of enclosure, rated losses, losses, and any internal arc designation assigned by the manufacturer. The practical point is that this standard does not treat the whole assembly like a conventional switchgear panel with a single continuous current rating - it is sized by power, losses, and thermal performance.
Enclosure class and thermal behaviour
Clause 5.12 introduces the rated class of enclosure, with classes from 0 to 30 in steps of 5 K of temperature-rise difference. The class is tied to the temperature rise inside the enclosure or compartment under rated losses, so the enclosure choice directly affects usable equipment rating and cooling design.
Clause 9.3 links enclosure selection to ambient air temperature at site and to the rated losses of the enclosure and the substation. Annex D provides the thermal performance method for enclosures. For users, this means the enclosure is not selected on appearance or size alone - its heat handling capability has to match the installed losses.
Design, construction, and protection of people
Clause 6 requires the main components to comply with their specific product standards, including the applicable railway standards for DC and AC traction switchgear, power transformers, and electronic power converters. Earthing has to follow EN 50522 and the functional requirements of EN IEC 61936-1.
The document also requires the enclosure to be designed against mechanical stress using the Eurocodes, with handling loads considered where subassemblies are shipped separately. Internal arc protection is addressed in Clause 6.9, and the accessible sides of the main components have to be respected when they are installed. This matters because the assembly may be in locations accessible to staff and, in some cases, to the public.
Type tests and routine tests
Clause 7 lists the mandatory type tests for insulation, temperature rise, short-time and peak withstand current, degree of protection, mechanical strength, internal arc performance, auxiliary and control circuits, sound level, and electromagnetic fields. Some tests can be replaced by calculation or another suitable verification method when the document allows it.
Annex A gives the method for Internal Arc Classification, and Clause 7.8 limits internal arc tests to the relevant compartment classes and accessibility cases. Clause 8 lists routine tests on the main circuit, auxiliary and control circuits, resistance where applicable, functional checks, and tests after site assembly. For buyers and inspectors, this is the core acceptance framework.
Selection, procurement, installation, and safety
Clause 9 gives selection guidance, including rated values, enclosure class, and internal arc considerations. Clause 10 lists the information to be exchanged with enquiries, tenders, and orders, and Table 5 summarises the technical requirements and ratings that should be agreed.
Clauses 11 and 12 cover transport, storage, installation, operation, maintenance, and safety. Clause 11 requires the manufacturer to specify the information needed for safe transport and installation, and Clause 12 ties safety to earthing, IP coding, and internal arc aspects. In practice, this helps users define responsibilities before equipment arrives on site.
What terms does SIST-TS CLC/TS 50711:2026 define?
- Prefabricated traction substation - a prefabricated traction substation is an assembly transported to site as a complete unit or in prepared subassemblies, with an enclosure containing at least AC or DC traction switchgear.
- Nominal voltage (Un) - nominal voltage is the approximate voltage value used to identify the traction system that the substation is intended to supply.
- AC traction switchgear - AC traction switchgear is high-voltage switchgear designed according to CLC/TS 50152-4 and operated at an AC traction supply voltage.
- DC traction switchgear - DC traction switchgear is high-voltage or low-voltage switchgear designed according to EN 50123-6 and operated at a DC traction supply voltage.
- Non-traction switchgear - non-traction switchgear is switchgear used at supply voltages other than the AC or DC traction-system voltages covered by this document.
- Walk-in type - a walk-in type prefabricated traction substation is operated from inside the enclosure.
- Non-walk-in type - a non-walk-in type prefabricated traction substation is operated from outside the enclosure.
- Prefabricated switching station - a prefabricated switching station is a prefabricated traction substation that includes traction switchgear and other main components, but not power transformers or electronic power converters.
Who uses SIST-TS CLC/TS 50711:2026?
SIST-TS CLC/TS 50711:2026 is used by railway infrastructure owners, traction power engineers, switchgear and enclosure manufacturers, integrators, test laboratories, contractors, and quality managers. It is especially useful when specifying, designing, type testing, purchasing, delivering, installing, or accepting fixed traction substations for AC or DC railway systems.
Buyers use it to state the required ratings, enclosure class, and internal arc performance. Manufacturers use it to design the enclosure, select compliant main components, prepare nameplates, and plan type and routine tests. Test bodies and inspectors use it to confirm temperature rise, dielectric strength, mechanical strength, earthing, and internal arc behaviour.
What changed in SIST-TS CLC/TS 50711:2026 from the previous edition?
SIST-TS CLC/TS 50711:2026 is based on EN IEC 62271-202:2022 and adapts that framework for railway traction substations. It replaces or refines several clauses so they fit AC and DC electric traction systems, railway service conditions, and railway-specific product standards.
The document also introduces its own treatment of rated power, rated class of enclosure, and enclosure thermal performance, and it replaces the sound-level and thermal annex content with railway-specific methods. It adds railway-focused references such as EN 50123-6, CLC/TS 50152-4, EN 50121-5, EN 50122-1, EN 50125-2, EN 50328, EN 50329, EN 50522, and EN IEC 61936-1.
Which standards are used with SIST-TS CLC/TS 50711:2026?
| Standard | What it contributes |
|---|---|
| EN 62271-1:2017 | Common specifications for high-voltage switchgear and controlgear |
| EN IEC 62271-202:2022 | Base structure and railway prefabricated substation concepts |
| EN 50123-6:2003 | DC traction switchgear |
| CLC/TS 50152-4:2021 | AC metal-enclosed traction switchgear |
| EN 50123-1:2003 | General DC switchgear provisions |
| EN 50328:2003 | Electronic power converters for substations |
| EN 50329:2003 | Traction transformers |
| EN 50121-5:2017 | EMC emission and immunity for fixed power supply installations |
| EN 50122-1:2022 | Earthing and return circuit safety |
| EN 50124-1:2017 | Insulation coordination and creepage distances |
| EN 50125-2:2002 | Environmental conditions for fixed electrical installations |
| EN 50163:2004 | Supply voltages of traction systems |
| EN 50522:2022 | Earthing of power installations above 1 kV AC |
| EN IEC 61936-1:2021 | General rules for high-voltage power installations |
| EN 60529:1991 | IP degrees of protection |
| EN 1990 to EN 1999 | Structural design rules, including concrete, steel, timber, masonry, and aluminium |
| EN 62194:2005 | Thermal performance of enclosures |
| IEC/TR 62271-312:2021 | Transferability of type tests for prefabricated substations |
What does the SIST-TS CLC/TS 50711:2026 document contain?
The document contains the clause-by-clause requirements for service conditions, ratings, design, testing, selection, procurement information, transport, installation, safety, and environmental influence. It includes formulas for rated power and losses, plus a method for relating enclosure losses to thermal performance.
It also includes detailed test provisions for dielectric tests, temperature rise tests, short-circuit withstand, internal arc tests, sound level verification, and electromagnetic field assessment. Figures and tables support the practical methods, including temperature-rise arrangements, internal arc identification, earthing examples, transferability criteria, and a summary table of technical requirements and ratings.
Relations
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Refers
kSIST FprEN 1999-1-1:2022 - Eurocode 9 - Design of aluminium structures - Part 1-1: General rules - Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
- Effective Date
- 19-May-2026
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Frequently Asked Questions
SIST-TS CLC/TS 50711:2026 is a technical specification published by the Slovenian Institute for Standardization (SIST). Its full title is "Railway applications - Fixed installations - High-voltage/low-voltage prefabricated substations in AC and DC electric traction systems". This standard covers: This document specifies - the service conditions; - rated characteristics; - general structural requirements; and - test methods of prefabricated traction substations for use in AC and DC electric traction systems, which as a minimum contain an enclosure and a traction switchgear designed and manufactured according to - EN 50123 6 in DC electric traction systems; - CLC/TS 50152 4 in AC electric traction systems. Traction substations using non-type tested traction switchgear are covered by EN IEC 61936 1:2021. NOTE 1 Due to the type testing requirements on the prefabricated traction substations only type tested traction switchgear is considered. The enclosures of the prefabricated traction substations for use in AC and DC electric traction systems are - designed for outdoor installation at locations with or without public accessibility; - connected by insulated cable; - operated from inside (walk-in type) or outside (non-walk-in type). NOTE 2 Prefabricated traction substations for railway applications are typically of the walk-in type due to the rating and resulting dimensions of the AC or DC traction switchgear. Prefabricated traction substations can be situated at ground level or partially or completely below ground level. In general a prefabricated traction substation comprises an enclosure, a traction switchgear and can include the following additional main components: - power transformers; - electronic power converters; - high-voltage and/or low-voltage switchgear and controlgear; - high-voltage and/or low-voltage interconnections; - auxiliary equipment and circuits. However, relevant provisions of this document are applicable to designs where not all these main components exist. NOTE 3 The term "main component”"is defined in 3.3.103 of EN IEC 62271 202:2022. NOTE 4 For example, a switching station in an AC electric traction system consisting of an AC metal-enclosed traction switchgear and auxiliary circuits only. NOTE 5 EN IEC 61936 1:2021 provides general rules for the design and erection of high-voltage power installations. As well, it specifies additional requirements for the external connections, erection and operation at the place of installation of high-voltage prefabricated traction substations compliant with EN IEC 62271 202:2022, which are regarded as a main component of such installation. Non-prefabricated traction substations, are generally covered by EN IEC 61936 1:2021. This document covers designs using natural ventilation and/or any other kind of cooling system. Due to the large number of different main components being addressed in this document the expression "main components shall comply with (the applicable subclause of) their specific product standard" is used in this document. This means that reference is to - EN 50123 6:2003 for DC traction switchgear; - to other parts of the EN 50123 series for switching devices also measurement, control and protection devices for DC traction applications; - CLC/TS 50152 4:2021 for AC traction switchgear; - other parts of the EN 50152 series for switching devices and also measurement, control and protection devices for AC traction applications; - EN 50328:2003 for electronic power converters; - EN 50329:2003 for traction power transformers; - EN IEC 61439-1:2021 for low-voltage non-traction switchgear; and - EN IEC 62271 200:2021 for high-voltage non-traction switchgear.
This document specifies - the service conditions; - rated characteristics; - general structural requirements; and - test methods of prefabricated traction substations for use in AC and DC electric traction systems, which as a minimum contain an enclosure and a traction switchgear designed and manufactured according to - EN 50123 6 in DC electric traction systems; - CLC/TS 50152 4 in AC electric traction systems. Traction substations using non-type tested traction switchgear are covered by EN IEC 61936 1:2021. NOTE 1 Due to the type testing requirements on the prefabricated traction substations only type tested traction switchgear is considered. The enclosures of the prefabricated traction substations for use in AC and DC electric traction systems are - designed for outdoor installation at locations with or without public accessibility; - connected by insulated cable; - operated from inside (walk-in type) or outside (non-walk-in type). NOTE 2 Prefabricated traction substations for railway applications are typically of the walk-in type due to the rating and resulting dimensions of the AC or DC traction switchgear. Prefabricated traction substations can be situated at ground level or partially or completely below ground level. In general a prefabricated traction substation comprises an enclosure, a traction switchgear and can include the following additional main components: - power transformers; - electronic power converters; - high-voltage and/or low-voltage switchgear and controlgear; - high-voltage and/or low-voltage interconnections; - auxiliary equipment and circuits. However, relevant provisions of this document are applicable to designs where not all these main components exist. NOTE 3 The term "main component”"is defined in 3.3.103 of EN IEC 62271 202:2022. NOTE 4 For example, a switching station in an AC electric traction system consisting of an AC metal-enclosed traction switchgear and auxiliary circuits only. NOTE 5 EN IEC 61936 1:2021 provides general rules for the design and erection of high-voltage power installations. As well, it specifies additional requirements for the external connections, erection and operation at the place of installation of high-voltage prefabricated traction substations compliant with EN IEC 62271 202:2022, which are regarded as a main component of such installation. Non-prefabricated traction substations, are generally covered by EN IEC 61936 1:2021. This document covers designs using natural ventilation and/or any other kind of cooling system. Due to the large number of different main components being addressed in this document the expression "main components shall comply with (the applicable subclause of) their specific product standard" is used in this document. This means that reference is to - EN 50123 6:2003 for DC traction switchgear; - to other parts of the EN 50123 series for switching devices also measurement, control and protection devices for DC traction applications; - CLC/TS 50152 4:2021 for AC traction switchgear; - other parts of the EN 50152 series for switching devices and also measurement, control and protection devices for AC traction applications; - EN 50328:2003 for electronic power converters; - EN 50329:2003 for traction power transformers; - EN IEC 61439-1:2021 for low-voltage non-traction switchgear; and - EN IEC 62271 200:2021 for high-voltage non-traction switchgear.
SIST-TS CLC/TS 50711:2026 is classified under the following ICS (International Classification for Standards) categories: 29.280 - Electric traction equipment. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST-TS CLC/TS 50711:2026 has the following relationships with other standards: It is inter standard links to SIST EN 1993-1-8:2005, SIST EN 50163:2005, kSIST FprEN 1998-1-1:2024, SIST EN 1993-1-10:2005, kSIST FprEN 1999-1-4:2022, kSIST FprEN 1993-1-2:2023, SIST EN 60529:1997/A1:2000, SIST EN 60529:1997/A2:2014, kSIST FprEN 1993-1-14:2025, kSIST FprEN 1992-1-2:2023, kSIST FprEN 1999-1-1:2022, kSIST FprEN 1996-1-2:2024, SIST EN 50522:2022/A1:2024, kSIST FprEN 1999-1-2:2022, kSIST FprEN 1997-1:2024. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST-TS CLC/TS 50711:2026 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-oktober-2026
Železniške naprave - Fiksni postroji - Visokonapetostne/nizkonapetostne
predizdelane napajalne postaje v sistemih izmeničnih in enosmernih električnih
vlek
Railway applications - Fixed installations - High-voltage/low-voltage prefabricated
substations in AC and DC electric traction systems
Bahnanwendungen - Ortsfeste Anlagen - Fabrikfertige Stationen für
Hochspannung/Niederspannung in AC und DC Bahnenergieversorgungssystemen
Applications ferroviaires - Installations fixes - Postes préfabriqués haute tension/basse
tension dans AC et DC réseau de traction électrique
Ta slovenski standard je istoveten z: CLC/TS 50711:2026
ICS:
29.280 Električna vlečna oprema Electric traction equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL SPECIFICATION CLC/TS 50711
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION May 2026
ICS 29.280
English Version
Railway applications - Fixed installations - High-voltage/low-
voltage prefabricated substations in AC and DC electric traction
systems
Applications ferroviaires - Installations fixes - Postes Bahnanwendungen - Ortsfeste Anlagen - Fabrikfertige
préfabriqués haute tension/basse tension dans AC et DC Stationen für Hochspannung/Niederspannung in AC und
réseau de traction électrique DC Bahnenergieversorgungssystemen
This Technical Specification was approved by CENELEC on 2026-04-06.
CENELEC members are required to announce the existence of this TS in the same way as for an EN and to make the TS available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TS 50711:2026 E
Contents Page
European foreword . 6
Introduction . 7
1 Scope [1] . 8
2 Normative references [2] . 9
3 Terms and definitions [3] . 11
4 Normal and special service conditions [4] . 13
4.1 Normal service conditions [4.1] . 13
4.2 Special service conditions [4.2] . 13
5 Ratings [5] . 13
5.1 General [5.1] . 13
5.2 Rated voltage (U ) [5.2] . 14
r
5.3 Rated insulation level (U , U , U ) [5.3] . 14
d p s
5.4 Rated frequency (f ) [5.4] . 14
r
5.5 Rated continuous current (I ) [5.5] . 14
r
5.6 Rated short-time withstand current (I ) [5.6] . 15
k
5.7 Rated peak withstand current (I ) [5.7] . 15
p
5.8 Rated durations of short-circuit (t ) [5.8] . 15
k
5.9 Rated supply voltage of auxiliary and control circuits (U ) [5.9] . 15
a
5.10 Rated supply frequency of auxiliary and control circuits [5.10] . 15
5.11 Rated pressure of compressed gas supply for controlled pressure systems [5.11] . 15
5.12 Rated power of prefabricated traction substation and class of enclosure [5.101] . 16
5.12.1 General . 16
5.12.2 Rated class of enclosure [5.101.2] . 16
5.12.3 Rated losses . 16
5.12.4 Rated power of the prefabricated traction substation [5.101.1] . 17
5.12.5 Losses of the prefabricated traction substation . 18
5.12.6 Examples . 19
5.13 Ratings of the Internal Arc Classification (IAC) [5.102] . 20
5.13.1 General [5.102.1] . 20
5.13.2 Internal arc identifier . 20
5.13.3 Types of accessibility [5.102.2] . 21
5.13.4 Accessible sides . 22
5.13.5 Rated arc fault current and rated arc fault duration [5.102.3 and 5.102.4] . 22
6 Design and construction [6] . 23
6.1 General . 23
6.2 Requirements for liquids [6.1] . 23
6.3 Requirements for gases in switchgear and controlgear [6.2] . 23
6.4 Earthing of switchgear and controlgear [6.3] . 23
6.5 Nameplates [6.11] . 24
6.6 Creepage distances for outdoor insulators [6.15] . 24
6.7 Electromagnetic compatibility (EMC) [6.19] . 24
6.8 Protection of the prefabricated traction substation against mechanical stress
[6.101] . 24
6.9 Internal arc fault [6.103] . 24
6.10 Enclosure [6.104] . 24
6.10.1 General [6.104.1] . 24
6.10.2 Environmental considerations [6.104.3]. 25
6.10.3 Covers and doors [6.104.4] . 25
6.11 Other provisions [6.105] . 25
6.12 Sound emission [6.106] . 25
6.13 Electromagnetic fields [6.107] . 25
6.14 Solar radiation [6.108] . 25
7 Type tests [7] . 26
7.1 Applicability . 26
7.2 General [7.1] . 26
7.3 Dielectric tests [7.2] . 27
7.3.1 General [7.2.1] . 27
7.3.2 Arrangement of the equipment [7.2.4] . 27
7.3.3 Tests of switchgear and controlgear of Ur ≤ 245 kV [7.2.7] . 27
7.3.4 Tests on the high-voltage main components [7.2.101] . 27
7.3.5 Tests on low-voltage interconnection [7.2.102] . 27
7.4 Continuous current test [7.5] . 28
7.4.1 General [7.5.101] . 28
7.4.2 Test conditions [7.5.102] . 28
7.4.3 Test methods [7.5.103] . 29
7.4.4 Measurements [7.5.104] . 30
7.4.5 Acceptance criteria [7.5.105] . 31
7.4.6 Continuous current test under solar radiation [7.5.106] . 32
7.4.7 Calculation of temperature rise . 32
7.4.8 Transfer of results . 33
7.5 Short-time withstand current and peak withstand current tests [7.6] . 33
7.6 Electromagnetic compatibility tests (EMC) [7.9] . 34
7.7 Calculations and mechanical tests [7.101] . 34
7.8 Internal arc test [7.102] . 34
7.9 Measurement or calculation of electromagnetic fields [7.103] . 36
8 Routine tests [8] . 36
8.1 General [8.1] . 36
8.2 Dielectric test on the main circuit [8.2]. 36
8.3 Test on auxiliary and control circuits [8.3] . 36
8.4 Measurement of the resistance of the main circuit [8.4] . 36
8.5 Other functional tests [8.101] . 36
8.6 Tests after assembly on site [8.102] . 36
9 Guide to the selection of prefabricated traction substation [9] . 37
9.1 General [9.101] . 37
9.2 Selection of rated values [9.102] . 37
9.3 Selection of class of enclosure [9.103] . 37
9.4 Internal arc fault [9.104] . 37
9.4.1 General [9.104.1] . 37
9.4.2 Supplementary protective measures [9.104.3] . 37
9.4.3 Considerations for the selection and installation [9.104.4]. 37
9.5 Summary of technical requirements and ratings [9.105] . 37
10 Information to be given with enquiries, tenders and orders (informative) [10] . 42
10.1 General [10.1] . 42
10.2 Information with enquiries and orders [10.2] . 42
10.3 Information with tenders [10.3] . 43
11 Transport, storage, installation, operation, maintenance [11] . 43
11.1 General [11.1] . 43
11.2 Conditions during transport, storage and installation [11.2] . 44
11.3 Installation [11.3] . 44
11.4 Operating instructions [11.4] . 44
11.5 Maintenance [11.5]. 44
12 Safety [12] . 44
12.1 General [12.101] . 44
12.2 Electrical aspects [12.102] . 44
12.3 Internal arc aspects [12.105] . 44
13 Influence of the product on the environment [13] . 44
Annex A (normative) Internal arc fault – Method to verify the Internal Arc Classification
(IAC) . 45
A.1 General [A.1] . 45
A.2 Indicators (for assessing the thermal effects of the gases) [A.3] . 46
A.3 Test procedure [A.6] . 46
Annex B (normative) Test to verify the sound level of a prefabricated traction substation . 47
Annex C (informative) Examples of earthing circuits . 48
Annex D (informative) Method of evaluating the thermal performance of enclosures . 50
D.1 General . 50
D.2 Flow chart for establishing the absorption factor . 51
D.3 Evaluation of the heat load . 52
D.4 Environmental conditions . 52
D.4.1 Ambient temperature limits . 52
D.4.2 Solar radiation . 52
D.4.3 Wind . 53
D.5 Determination of the enclosure absorption factor . 53
D.6 Result and presentation . 53
Bibliography . 54
Figures
Figure 1 — Illustrative arrangements of temperature rise tests . 29
Figure 2 — Example of air temperature measurement locations inside a prefabricated
traction substation . 31
Figure A.1 — Flow chart Determination of internal arc identifiers . 45
Figure C.1 — Example of earthing circuit with main components installed insulated from
the floor respectively enclosure . 49
Figure D.1 — Flow chart with concept of rated losses, class of enclosure and rated
power . 51
Figure D.2 — Flow chart for establishing the absorption factor . 52
Tables
Table 1 — Determination of the rated power for Example 4 . 20
Table 2 — Type tests . 26
Table 3 — Transferability criteria for temperature rise performance . 33
Table 4 — Transferability criteria for internal arc fault withstand performance . 35
Table 5 — Summary of technical requirements and ratings for prefabricated traction
substations . 38
Table D.1 — Convection heat transfer coefficients . 53
European foreword
This document (CLC/TS 50711:2026) has been prepared by CLC/SC 9XC “Electric supply and earthing
systems for public transport equipment and ancillary apparatus (Fixed installations)”.
include switchgear operated at traction system voltages as specified in EN 50163.
It is based on EN IEC 62271-202:2022 “High-voltage switchgear and controlgear - Part 202: High-voltage/low-
voltage prefabricated traction substation” and contains detailed requirements specific for prefabricated traction
substations operated in a railway environment.
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.
Any feedback and questions on this document should be directed to the users’ national committee. A complete
listing of these bodies can be found on the CENELEC website.
Introduction
A prefabricated traction substation is defined as a type-tested assembly comprising an enclosure containing
AC and/or DC traction switchgears and in general also all or some of the following main components: power
transformers, high-voltage and/or low-voltage switchgear, electronic power converters, electrical high-voltage
and/or low-voltage interconnections. The prefabricated traction substation can include all necessary auxiliary
and control equipment for its operation. The purpose being to supply traction power from a high-voltage system
and/or vice versa (high-voltage/low-voltage traction substation) or distribute electric power in an electric
traction system (traction switching station).
These prefabricated traction substations can be in locations accessible to the public and should ensure
protection not only to authorized persons but also to general public under the specified service conditions.
Therefore, in addition to the specified characteristics, ratings and relevant test procedures, particular attention
has been paid to the specification concerning the protection of persons, both operators and general public with
respect to the railway environment. Use of type-tested main components and suitable design and construction
of the assembly ensure this protection. The correct design and performance of the prefabricated traction
substation is verified by means of relevant type tests and routine tests described in this document, including
internal arc verification (if applicable).
This document needs to be read in conjunction with EN 62271-1:2017 and EN IEC 62271-202:2022.
Where a particular clause of EN IEC 62271-202:2022 is not mentioned in this document, that clause applies
as far as reasonable. Where this document states “addition” or “replacement”, the relevant text of
EN IEC 62271-202:2022 needs to be adapted accordingly.
The numbering of clauses in EN 62271 series is not used in this European Document. For easier
understanding the numbering of clauses in EN IEC 62271-202:2022 is given in square brackets.
Where terms defined in EN 62271-1:2017 and EN IEC 62271-202:2022 conflict with definitions of the same
terms as given in IEC 60050-811:2017 or of the other railway application documents listed in the normative
references, the definitions in EN 62271-1:2017 and EN IEC 62271-202:2022 need to be used.
NOTE 1 The suffix N which appears in this document for rated values is not present in EN 62271-1 and
EN IEC 62271−202.
References in subclauses of EN 62271-1:2017 and EN IEC 62271-202:2022 need to be replaced by
references to applicable subclauses in this document as far as reasonably possible. Also the
term ”prefabricated substation” needs to be read ”prefabricated traction substation” for use in this document.
The term ”switchgear and controlgear” is used in the EN 62271 series. It will be kept for the headlines even
when the text of the clause or subclause addresses other kinds of main components.
NOTE 2 Expressions in single quotes indicate a technical requirement which can be available in the specific product
standard under a different title.
NOTE 3 Expressions in double quotes indicate terms consisting of several words.
1 Scope [1]
This document specifies
— the service conditions;
— rated characteristics;
— general structural requirements; and
— test methods
of prefabricated traction substations for use in AC and DC electric traction systems, which as a minimum
contain an enclosure and a traction switchgear designed and manufactured according to
— EN 50123-6 in DC electric traction systems;
— CLC/TS 50152-4 in AC electric traction systems.
Traction substations using non-type tested traction switchgear are covered by EN IEC 61936-1:2021.
NOTE 1 Due to the type testing requirements on the prefabricated traction substations only type tested traction
switchgear is considered.
The enclosures of the prefabricated traction substations for use in AC and DC electric traction systems are
— designed for outdoor installation at locations with or without public accessibility;
— connected by insulated cable;
— operated from inside (walk-in type) or outside (non-walk-in type).
NOTE 2 Prefabricated traction substations for railway applications are typically of the walk-in type due to the rating and
resulting dimensions of the AC or DC traction switchgear.
Prefabricated traction substations can be situated at ground level or partially or completely below ground level.
In general a prefabricated traction substation comprises an enclosure, a traction switchgear and can include
the following additional main components:
— power transformers;
— electronic power converters;
— high-voltage and/or low-voltage switchgear and controlgear;
— high-voltage and/or low-voltage interconnections;
— auxiliary equipment and circuits.
However, relevant provisions of this document are applicable to designs where not all these main components
exist.
NOTE 3 The term “main component” is defined in 3.3.103 of EN IEC 62271-202:2022.
NOTE 4 For example, a switching station in an AC electric traction system consisting of an AC metal-enclosed traction
switchgear and auxiliary circuits only.
NOTE 5 EN IEC 61936-1:2021 provides general rules for the design and erection of high-voltage power installations.
As well, it specifies additional requirements for the external connections, erection and operation at the place of installation
of high-voltage prefabricated traction substations compliant with EN IEC 62271-202:2022, which are regarded as a main
component of such installation. Non-prefabricated traction substations, are generally covered by EN IEC 61936-1:2021.
This document covers designs using natural ventilation and/or any other kind of cooling system.
Due to the large number of different main components being addressed in this document the expression “main
components shall comply with (the applicable subclause of) their specific product standard” is used in this
document. This means that reference is to
— EN 50123-6:2003 for DC traction switchgear;
— to other parts of the EN 50123 series for switching devices also measurement, control and protection
devices for DC traction applications;
— CLC/TS 50152-4:2021 for AC traction switchgear;
— other parts of the EN 50152 series for switching devices and also measurement, control and protection
devices for AC traction applications;
— EN 50328:2003 for electronic power converters;
— EN 50329:2003 for traction power transformers;
— EN IEC 61439-1:2021 for low-voltage non-traction switchgear; and
— EN IEC 62271-200:2021 for high-voltage non-traction switchgear.
2 Normative references [2]
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 1990 (all parts), Eurocode - Basis of structural and geotechnical design
EN 1991 (all parts), Eurocode 1 - Actions on structures
EN 1992 (all parts), Eurocode 2 - Design of concrete structures
EN 1993 (all parts), Eurocode 3 - Design of steel structures
EN 1994 (all parts), Eurocode 4 - Design of composite steen and concrete structures
EN 1995 (all parts), Eurocode 5 - Design of timber structure
EN 1996 (all parts), Eurocode 6 - Design of masonry structures
EN 1997 (all parts), Eurocode 7 - Geotechnical design
EN 1998 (all parts), Eurocode 8 - Design of structures for earthquake resistance
As impacted by EN 50123-6:2003:A1:2014.
As impacted by EN 50328:2003/corrigendum Dec. 2006.
As impacted by EN 50329:2003/corrigendum Dec. 2006 and EN 50329:2003/A1:2010.
As impacted by EN IEC 61439-1:2021/AC2022-01 and EN IEC 61439-1:2021/AC2023-11.
As impacted by EN IEC 62271-200:2021/A1:2024.
EN 1999 (all parts), Eurocode 9 - Design of aluminium structures
EN 50121-5:2017, Railway applications - Electromagnetic compatibility - Part 5: Emission and immunity of
fixed power supply installations and apparatus
EN 50122-1:2022, Railway applications - Fixed installations - Electrical safety, earthing and the return circuit
- Part 1: Protective provisions against electric shock
EN 50123-1:2003, Railway applications - Fixed installations - D.C. switchgear - Part 1: General
EN 50123-6:2003, Railway applications - Fixed installations - D.C. switchgear - Part 6: D.C. switchgear
assemblies
EN 50124-1:2017, Railway applications - Insulation coordination - Part 1: Basic requirements - Clearances
and creepage distances for all electrical and electronic equipment
EN 50125-2:2002, Railway applications - Environmental conditions for equipment - Part 2: Fixed electrical
installations
CLC/TS 50152-4:2021, Railway applications - Fixed installations - Particular requirements for AC switchgear
- Part 4: AC metal-enclosed traction switchgear
EN 50163:2004, Railway applications - Supply voltages of traction systems
EN 50329:2003, Railway applications - Fixed installations - Traction transformers
EN 50500:2008, Measurement procedures of magnetic field levels generated by electronic and electrical
apparatus in the railway environment with respect to human exposure
EN 50522:2022, Earthing of power installations exceeding 1 kV a.c
EN ISO 52016-1:2017, Energy performance of buildings - Energy needs for heating and cooling, internal
temperatures and sensible and latent heat loads - Part 1: Calculation procedures (ISO 52016-1:2017)
EN 60529:1991, Degrees of protection provided by enclosures (IP Code)
EN IEC 61936-1:2021, Power installations exceeding 1 kV AC and 1,5 kV DC - Part 1: AC (IEC 61936-1:2021)
As impacted by EN 50121-5:2017/A1:2019.
As impacted by EN 50122-1:2022/A1:2025.
As impacted by EN 50123-6:2003/A1:2014.
As impacted by EN 50124-1:2017/prA1:2024.
As impacted by EN 50125-2:2002/corrigendum Jun.2010.
As impacted by EN 50163:2004/A1:2007, EN 50163:2004/corrigendum May 2010, EN 50163:2004/AC:2013,
EN 50163:2004/A2:2020 and EN 50163:2004//A3:2022.
As impacted by EN 50329:2003/corrigendum Dec. 20026 and EN 50329:2003/A1:2010.
As impacted by EN 50500:2008/A1:2015.
As impacted by EN 50522:2022/A1:2024.
As impacted by EN 60529:1991/corrigendum May 1993, EN 60529:1991/A1:2000, EN 60529:1991/A2:2013,
EN 60529:1991/A2:2013/AC2019-02 and EN 60529:1991/AC2016-12.
EN 62271-1:2017, High-voltage switchgear and controlgear - Part 1: Common specifications for alternating
current switchgear and controlgear (IEC 62271-1:2017)
EN IEC 62271-200:2021, High-voltage switchgear and controlgear - Part 200: AC metal-enclosed
switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV (IEC 62271-200:2021)
EN IEC 62271-202:2022, High-voltage switchgear and controlgear - Part 202: AC prefabricated substations
for rated voltages above 1 kV and up to and including 52 kV (IEC 62271-202:2022)
IEC/TR 62271-312:2021, High-voltage switchgear and controlgear - Part 312: Guidance for the transferability
of type tests of high-voltage/low-voltage prefabricated substations
3 Terms and definitions [3]
For the purposes of this document, the terms and definitions given in EN IEC 62271-202:2022 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/”
NOTE 1 The terms “enclosure (of a prefabricated substation)”, ”compartment (of a prefabricated substation)” and ”main
component (of a prefabricated substation)”, definitions 3.3.101, 3.3.102 and 3.3.103 of EN IEC 62271-202:2022 are
essential for the understanding of this document.
NOTE 2 The term “enclosure (of a prefabricated substation)” as defined in 3.3.101 of EN IEC 62271-202:2022 does
not constitute that a prefabricated traction substation consists of a single enclosure only.
NOTE 3 In this document the terms
— assembly relates to the enclosure of the substation with the main components installed inside and
— compartment relates to a subsection of the substation enclosure.
This is different to EN IEC 62271-200:2021 where both terms are related to the switchgear and controlgear only.
3.1
nominal voltage
U
n
suitable approximate voltage value used to designate or identify a given supply system
Note 1 to entry: This value is also assigned to the voltage of a power transformer to show its usability in the supply
system.
Note 2 to entry: An electric traction system that is supplied by use of auto-transformers with 2 phases, having a phase
shift of 180° between them, is commonly named 2 x U according to the U supplied to the contact line system.
n n
[SOURCE: EN 50124-1:2017, 3.4.1, modified - Notes to entry added]
As impacted by EN 62271-1:2017/A1:2021.
As impacted by EN IEC 62271-200:2021/A1:2024.
As impacted by EN IEC 62271-202:2022/AC:2023-09.
3.2
AC traction switchgear
high-voltage switchgear designed according to CLC/TS 50152-4:2021 and operated at an AC supply voltage
of traction systems according to 4.1 of EN 50163:2004
3.3
DC traction switchgear
high-voltage or low-voltage switchgear designed according to EN 50123-6:2003 and operated at a DC supply
voltage of traction systems according to 4.1 of EN 50163:2004
3.4
non-traction switchgear
high-voltage or low-voltage switchgear operated at a supply voltage other than AC or DC supply voltages of
traction systems according to 4.1 of EN 50163:2004
Note 1 to entry: Non-traction switchgears are high-voltage or low-voltage switchgears used in general power supply
applications e.g. low-voltage AC or DC distribution boards or high-voltage switchgear and controlgear providing a three-
phase AC supply to power transformer rectifiers.
Note 2 to entry: This term is defined to easily distinguish AC from DC traction switchgear in this document.
3.5
converter
operative unit for electronic power conversion, comprising one or more electronic valve
devices, power transformers and filters if necessary and auxiliaries if any
Note 1 to entry, In English, the two spellings “convertor” and “converter” are in use, and both are correct. In this
document, the spelling “converter” is used in order to avoid duplications.
[SOURCE: IEC 60050-551:1998 551-12-01, modified - the term with the spelling convertor has been removed
and “transformers” has been replaced with “power transformers”]
3.6
structure
building or other object constructed to form a rigid support and/or to house several other objects
Note 1 to entry: E.g. supporting structure, enclosure or similar.
3.7
traction substation
substation
substation the main function of which is to supply an electric traction system and which
includes a traction switchgear as a minimum
Note 1 to entry: The synonym substation is used only when the context is clear.
Note 2 to entry: It includes equipment for protection and switching-off.
[SOURCE: IEC 60050-811:2017, 811-36-02, modified - “and which includes a traction switchgear as a
minimum” added to the definition, –Note 2 to entry added]
3.8
prefabricated
practice of assembling all the main components on or into a structure in a factory or other manufacturing sites
including all power, control and auxiliary interconnections also testing of the assemblies which are then
transported as a complete unit or in sub-assemblies to the construction site where the structure is to be located
Note 1 to entry: The place of final use is a construction site and not seen as factory or manufacturing site.
Note 2 to entry: All power, control and auxiliary interconnections include that all internal connections are present and
established. All external interfaces are prepared ready for connection.
Note 3 to entry: Subassemblies are only separated for transport and reconnected on site at predefined and fully
prepared interfaces. Subassemblies are a means to cope with transport restrictions.
3.9
prefabricated traction substation [3.2.101]
traction substation which is prefabricated and comprising an enclosure containing as a minimum an AC traction
switchgear or a DC traction switchgear
Note 1 to entry: Prefabricated enclosures themselves are not to be considered as prefabricated traction substations if
transported to the site of use without main components.
3.10
prefabricated AC traction substation
prefabricated traction substation containing an AC traction switchgear and in general complemented by high-
voltage and low-voltage interconnections as well as auxiliary equipment and circuits
3.11
prefabricated DC traction substation
prefabricated traction substation containing a DC traction switchgear and in general complemented by power
transformers, electronic power converters, high-voltage switchgear and controlgear, high-voltage and low-
voltage interconnections, auxiliary equipment and circuits
3.12
prefabricated switching station
prefabricated traction substation containing a traction switchgear and other main components except power
transformers and electronic power converters
3.13
standard size compartment
compartment of a prefabricated traction substation having a total internal volume of 15 m or higher and a total
internal volume excluding the main components of 10 m or higher
4 Normal and special service conditions [4]
4.1 Normal service conditions [4.1]
Subclause 4.1 of EN IEC 62271-202:2022 is applicable, except as follows:
— main components shall comply with the requirements for ‘normal service conditions’ of the specific product
standard.
NOTE 1 The altitude reference condition is 1 000 m as per EN 62271-1:2017. The altitude reference of
EN 50124-1:2017 (up to 2 000 m) applies to insulation coordination only and is not considered as reference condition in
this document.
Subclause 4.1.3 of EN 62271-1:2017 does not apply.
NOTE 2 Subclause 4.1.3 of EN 62271-1:2017 addresses service conditions for outdoor electrical equipment.
4.2 Special service conditions [4.2]
Subclause 4.2 of EN IEC 62271-202:2022 is replaced by the following:
For special service conditions, agreement shall be made between purchaser and supplier. EN 50125-2:2002
shall be taken as guidance for the selection of appropriate classifications.
5 Ratings [5]
5.1 General [5.1]
Subclause 5.1 of EN IEC 62271-202:2022 is replaced by the following:
The ratings of a prefabricated traction substation are the following:
a) nominal voltage Un of the traction system;
b) rated frequency (fr) of the traction switchgear;
c) rated power of the prefabricated traction substation, see 5.12.4;
d) rated class of enclosure, see 5.12.2;
e) rated losses (of the enclosure), see 5.12.3;
f) losses of the prefabricated traction substation, see 5.12.5;
g) ratings of the internal arc designation (IAC or IAV), if assigned by the manufacturer, see 5.13.
For main components the ratings of their applicable product standard apply.
5.2 Rated voltage (U ) [5.2]
r
Subclause 5.2 of EN IEC 62271-202:2022 is replaced by the following text:
There is no rated voltage assigned to the prefabricated traction substation. It is characterized by its nominal
voltage U of the traction system it is intended to supply. The nominal voltage U assigned to the prefabricated
n n
traction substation shall be the nominal voltage of th
...