SIST EN 50122-1:2022/A1:2025
(Amendment)Fixed installations for railway applications - Electrical safety, earthing and the return circuit - Part 1: Protective provisions against electric shock
Fixed installations for railway applications - Electrical safety, earthing and the return circuit - Part 1: Protective provisions against electric shock
This document specifies requirements for the protective provisions relating to electrical safety in fixed installations associated with AC and/or DC traction systems and to any installations that can be endangered by the electric traction power supply system. This also includes requirements applicable to vehicles on electrified lines. It also applies to all aspects of fixed installations which are necessary to ensure electrical safety during maintenance work within electric traction power supply systems.
This document applies to new electric traction power supply systems and major revisions to electric traction power supply systems for:
a) railways;
b) guided mass transport systems such as 1) tramways,
2) elevated and underground railways,
3) mountain railways,
4) trolleybus systems,
5) electric traction power supply systems for road vehicles, which use an overhead contact line system, and
6) magnetically levitated systems, which use a contact line system;
c) material transportation systems.
This document does not apply to:
a) electric traction power supply systems in underground mines,
b) cranes, transportable platforms and similar transportation equipment on rails, temporary structures (e.g. exhibition
structures) in so far as these are not supplied directly or via transformers from the contact line system and are not
endangered by the electric traction power supply system,
c) suspended cable cars,
d) funicular railways,
e) existing vehicles.
This document does not specify working rules for maintenance. The requirements within this document related to protection against electric shock are applicable to persons only.
Ortsfeste Anlagen für Bahnanwendungen - Elektrische Sicherheit, Erdung und Rückleitung - Teil 1: Schutzmaßnahmen gegen elektrischen Schlag
Installations Fixes pour applications ferroviaires - Sécurité électrique, mise à la terre et circuit de retour - Partie 1: Mesures de protection contre les chocs électriques
Fiksni postroji za železniške naprave - Električna varnost, ozemljitev in povratni tokokrog - 1. del: Zaščitni ukrepi proti električnemu udaru - Dopolnilo A1
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2025
Fiksni postroji za železniške naprave - Električna varnost, ozemljitev in povratni
tokokrog - 1. del: Zaščitni ukrepi proti električnemu udaru - Dopolnilo A1
Fixed installations for railway applications - Electrical safety, earthing and the return
circuit - Part 1: Protective provisions against electric shock
Ortsfeste Anlagen für Bahnanwendungen - Elektrische Sicherheit, Erdung und
Rückleitung - Teil 1: Schutzmaßnahmen gegen elektrischen Schlag
Installations Fixes pour applications ferroviaires - Sécurité électrique, mise à la terre et
circuit de retour - Partie 1: Mesures de protection contre les chocs électriques
Ta slovenski standard je istoveten z: EN 50122-1:2022/A1:2025
ICS:
13.260 Varstvo pred električnim Protection against electric
udarom. Delo pod napetostjo shock. Live working
29.280 Električna vlečna oprema Electric traction equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN 50122-1:2022/A1
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2025
ICS 29.280
English Version
Fixed installations for railway applications - Electrical safety,
earthing and the return circuit - Part 1: Protective provisions
against electric shock
Installations Fixes pour applications ferroviaires - Sécurité Ortsfeste Anlagen für Bahnanwendungen - Elektrische
électrique, mise à la terre et circuit de retour - Partie 1: Sicherheit, Erdung und Rückleitung - Teil 1:
Mesures de protection contre les chocs électriques Schutzmaßnahmen gegen elektrischen Schlag
This amendment A1 modifies the European Standard EN 50122-1:2022; it was approved by CENELEC on 2025-06-23. CENELEC
members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this amendment 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 amendment 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, 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
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 50122-1:2022/A1:2025 E
Contents Page
European foreword . 4
1 Modification to the Title . 5
2 Modification to 3.1, Electrical safety and hazards . 5
3 Modifications to 3.3, Return circuit . 5
4 Modifications to 3.4, Electric traction power supply system . 6
5 Modifications to 3.5, Contact line . 6
6 Modifications to 3.6, Corrosion and corrosion protection . 6
7 Modifications to 3.9, General terms . 6
8 Modification to 4.1, Overhead contact line . 6
9 Modification to 4.3, Trolleybuses and road vehicles using an overhead contact line . 7
10 Modification to 5.1.2, Design procedure . 7
11 Modification to 5.1.3, Electrical clearances . 8
12 Modification to 5.2.1, Calculation method for protection by clearance . 8
13 Modification to 5.2.2, Dimensions of clearances . 9
14 Modification to 5.2.6, Clearances above standing surfaces on vehicles . 9
15 Modification to 5.3.2, Common requirements for electrically protective obstacles . 9
16 Modification to 5.3.3.2, Taut string line method . 9
17 Modification to 5.3.4.2.2, Taut string line method . 9
18 Modification to 5.3.4.2.4, Taut string line method . 9
19 Modification to 5.4, Protection against direct contact with live parts mounted on vehicles .10
20 Modification to 5.6.5, Requirements for top contact ground level conductor rails in public areas
.............................................................................................................................................................10
21 Modification to 6.2.1.2, Exceptions in tunnels .10
22 Modification to 6.2.2.2, Exceptions in tunnels .10
23 Modification to 6.2.3.3, Bonding of overhead contact line supporting structures to the return
circuit .11
24 Modification to 7.1, General .11
25 Modification to 7.2.1, Equipment of protection Class I .11
26 Modification to 7.2.2, Equipment of protection Class II .11
27 Modification to 7.2.3, Cables .11
28 Modification to 7.2.4, Low voltage connected equipment .11
29 Modification to 7.3.1, Design of low voltage non-traction power supply .11
30 Modification to 7.3.2, Low voltage power supply by a TT system on the railway side .12
31 Modification to 7.3.3, Low voltage power supply by TN system .12
32 Modification to 7.3.4, Low voltage power supply by IT system .12
33 Modification to 7.3.5.1, AC railways . 12
34 Modification to 7.3.5.2, DC railways . 12
35 Modification to 8.2, Equipotential bonding . 12
36 Modification to 9.2.2.2, Effective touch voltage limits . 13
37 Modification to 9.3.2.2, Effective touch voltage limits . 13
38 Modification to 10.3.1, General requirements . 13
39 Modification to 10.5, Means of achieving safe isolation between sections . 13
40 Modification to B.2, Examples . 13
European foreword
This document (EN 50122-1:2022/A1:2025) has been prepared by SC 9XC, “Electric supply and earthing
systems for public transport equipment and ancillary apparatus (fixed installations)”, of CLC/TC 9X, “Electrical
and electronic applications for railways”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2026-08-31
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2028-08-31
conflicting with this document have to be
withdrawn
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.
This document has been prepared under a Standardization Request addressed to CENELEC by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
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.
1 Modification to the Title
Modify the first part of the title to read:
“Fixed installations for railway application - Electrical safety, earthing and the return circuit - Part 1: Protective
provisions against electric shock”
2 Modification to 3.1, Electrical safety and hazards
Replace the definition of 3.1.11 exposed-conductive-part with the following:
“conductive part of equipment that can be touched and that is not live under normal conditions, but that can
become energized when basic insulation fails
Note 1 to entry: A conductive part of electrical equipment, which can become energized only through contact with an
exposed-conductive-part which has become energized, is not considered to be an exposed-conductive-part itself.
[SOURCE: IEC 60050-195:2021, 195-06-10, modified – “become live” was replaced with “become energized”,
Note 1 to entry has been added.]”
Replace the whole terminological entry 3.1.17 with the following:
“protective conductor
conductor provided for purposes of electrical safety
[SOURCE: IEC 60050-195:2021, 195-02-09]”.
Add a new terminological entry 3.1.18:
“protective earthing conductor
PE conductor
protective conductor provided for protective earthing
[SOURCE: IEC 60050-195:2021, 195-02-11, modified, “protective grounding conductor, US” was deleted]”.
Renumber terminological entries:
— 3.1.18 in 3.1.19
— 3.1.19 in 3.1.20
— 3.1.20 in 3.1.21
3 Modifications to 3.3, Return circuit
Replace the definition of 3.3.1 extended return circuit with the following“
“part of the electric traction power supply system, which leads the current from loads such as vehicles or other
equipment to the source
EXAMPLE
— running rails;
— return conductor rails;
— return conductors;
— substation return conductors;
— booster transformer return conductors.
Note 1 to entry: The auto transformer system negative feeder is part of the feeding circuit.”
In 3.3.12 replace “per length of track” with “per length”.
4 Modifications to 3.4, Electric traction power supply system
In 3.4.7 replace “IEC 60050:441:1984” with ”IEC 60050-441:1984”.
In 3.4.8 and 3.4.9 replace “IEC 60050:601:1985” with ”IEC 60050-601:1985”.
5 Modifications to 3.5, Contact line
Replace the first line of the definition of 3.5.2 contact line with the following:
“conductor system for supplying electric energy to vehicles through current-collecting equipment”
In 3.5.10 replace “broken overhead contact wire” with “broken contact wire”.
6 Modifications to 3.6, Corrosion and corrosion protection
Delete terminological entry 3.6.2
Renumber terminological entry 3.6.3 in 3.6.2, delete the specific use “” and replace the
definition with:
“unintended current in earth and/or in conductive structures
Note 1 to entry: In AC electric traction power supply systems, currents in earth are intended.”
Renumber terminological entry 3.6.4 in 3.6.3
7 Modifications to 3.9, General terms
In 3.9.7 replace “fault-free” with “normal”.
8 Modification to 4.1, Overhead contact line
In the first paragraph, the third paragraph, the Note 1 and the Note 2 replace “overhead contact wire” with
“contact wire” (four times).
In Figure 1, replace the Key with the following:
“
TOR top of rail level (cant to be neglected)
HP highest point of the catenary wire or contact wire above TOR
OCLZ overhead contact line zone
CCZ current collector zone
TCL track centre line
LL lower limit of CCZ, if OCLZ is not present
X maximum unidirectional (half) horizontal width of OCLZ at top of rail level
Y maximum unidirectional (half) horizontal width of CCZ
Z difference between height of HP and S
H
S width of lateral movement of the current collector
S lateral safety distance for the broken or dewired current collector
S vertical safety distance for the broken or dewired current collector
S electrical clearance (= d in accordance with 5.1)
el
S maximum limit of current collector zone above TOR
H
L current collector width (shape and height of current collector are only for illu
...
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