SIST EN IEC 60974-4:2025

SLOVENSKI STANDARD
01-september-2025
Oprema za obločno varjenje - 4. del: Perodični pregledi in preskušanje (IEC 60974-
4:2025)
Arc welding equipment - Part 4: Periodic inspection and testing (IEC 60974-4:2025)
Lichtbogenschweißeinrichtungen - Teil 4: Wiederkehrende Inspektion und Prüfung (IEC
60974-4:2025)
Matériel de soudage à l'arc - Partie 4: Inspection et essais périodiques (IEC 60974-
4:2025)
Ta slovenski standard je istoveten z: EN IEC 60974-4:2025
ICS:
25.160.30 Varilna oprema Welding equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60974-4

NORME EUROPÉENNE
EUROPÄISCHE NORM August 2025
ICS 25.160 Supersedes EN 60974-4:2016
English Version
Arc welding equipment - Part 4: Periodic inspection and testing
(IEC 60974-4:2025)
Matériel de soudage à l'arc - Partie 4: Inspection et essais Lichtbogenschweißeinrichtungen - Teil 4: Wiederkehrende
périodiques Inspektion und Prüfung
(IEC 60974-4:2025) (IEC 60974-4:2025)
This European Standard was approved by CENELEC on 2025-07-08. 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, 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 IEC 60974-4:2025 E

European foreword
The text of document 26/769/FDIS, future edition 4 of IEC 60974-4, prepared by TC 26 "Electric
welding" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2026-08-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2028-08-31
document have to be withdrawn
This document supersedes EN 60974-4:2016 and all of its amendments and corrigenda (if any).
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.
Endorsement notice
The text of the International Standard IEC 60974-4:2025 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60038:2009 NOTE Approved as EN 60038:2011
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-151 - International Electrotechnical Vocabulary (IEV) - - -
Part 151: Electrical and magnetic devices
IEC 60974-1 2021 Arc welding equipment - Part 1: Welding power EN IEC 60974-1 2022
sources
+ A11 2022
- - + A12 2023
- - + A13 2025
IEC 60974-6 2015 Arc welding equipment - Part 6: Limited duty EN 60974-6 2016
equipment
IEC 61140 - Protection against electric shock - Common EN 61140 -
aspects for installation and equipment
IEC 61557-2 2019 Electrical safety in low voltage distribution EN IEC 61557-2 2021
systems up to 1 000 V AC and 1 500 V DC -
Equipment for testing, measuring or monitoring
of protective measures - Part 2: Insulation
resistance
IEC 61557-4 2019 Electrical safety in low voltage distribution EN IEC 61557-4 2021
systems up to 1 000 V AC and 1 500 V DC -
Equipment for testing, measuring or monitoring
of protective measures - Part 4: Resistance of
earth connection and equipotential bonding
IEC 61557-16 2023 Electrical safety in low voltage distribution EN IEC 61557-16 2024
systems up to 1 000 V AC and 1 500 V DC -
Equipment for testing, measuring or monitoring
of protective measures - Part 16: Equipment for
testing the effectiveness of the protective
measures of electrical equipment and/or medical
electrical equipment
IEC 60974-4 ®
Edition 4.0 2025-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 4: Periodic inspection and testing

Matériel de soudage à l'arc –
Partie 4: Inspection et essais périodiques
ICS 25.160  ISBN 978-2-8327-0462-2

IEC 60974-4:2025-06(en-fr)
– 2 – IEC 60974-4:2025 © IEC 2025
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 General requirements . 9
4.1 Qualification of personnel . 9
4.2 Test conditions . 9
4.3 Measuring instruments . 9
4.4 PERIODIC INSPECTION and testing. 9
4.5 MAINTENANCE . 9
4.6 Test after REPAIR . 10
4.7 Test sequence . 10
5 Protection against electrical shock . 10
5.1 VISUAL INSPECTION . 10
5.2 Continuity of the protective circuit . 11
5.3 Insulation resistance . 11
5.4 WELDING CIRCUIT TOUCH CURRENT . 12
5.5 TOUCH CURRENT in normal condition . 13
5.6 Protective conductor current . 14
5.7 NO-LOAD VOLTAGE (U ) . 15
6 Functional test . 17
6.1 General . 17
6.2 Supply-circuit on/off switching device . 17
6.3 Voltage-reducing device. 17
6.4 Magnetic gas valve . 17
6.5 Signal and control lamps . 17
7 Documentation . 18
7.1 Test report . 18
7.2 Labelling . 18
Annex A (informative) Checklist for the VISUAL INSPECTION . 19
Annex B (informative) Example of a test report after REPAIR . 20
Annex C (informative) Equipment not built in accordance with current IEC 60974-1 . 21
C.1 Welding equipment not built in accordance with IEC 60974-1 . 21
C.2 Determination of NO-LOAD VOLTAGE for welding equipment built according to
IEC 60974-1:1998 and IEC 60974-1:1998/AMD1:2000 or earlier . 21
Annex D (normative) Battery-powered WELDING POWER SOURCES . 22
D.1 General . 22
D.2 Protection against electrical shock . 22
D.2.1 VISUAL INSPECTION . 22
D.2.2 Continuity of the protective circuit . 23
D.2.3 Insulation resistance . 23
D.2.4 WELDING CIRCUIT TOUCH CURRENT. 23
D.2.5 TOUCH CURRENT in normal condition . 23
D.2.6 Protective conductor current . 23
D.2.7 NO-LOAD VOLTAGE (U ) . 23
IEC 60974-4:2025 © IEC 2025 – 3 –
D.3 Functional tests . 23
Bibliography . 24

Figure 1 – Example for the measurement of insulation resistance . 12
Figure 2 – Example for the measurement of WELDING CIRCUIT TOUCH CURRENT . 13
Figure 3 – Example for the measurement of TOUCH CURRENT in normal condition . 13
Figure 4 – Principles of protective conductor current measurement for single phase

equipment . 15
Figure 5 – Measurement of RMS values. 16
Figure 6 – Measurement of peak values . 16

Table 1 – Test sequence on used arc welding equipment . 10
Table 2 – Insulation resistance . 11
Table 3 – Allowable NO-LOAD VOLTAGEs depending on the environment . 15

– 4 – IEC 60974-4:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ARC WELDING EQUIPMENT –
Part 4: Periodic inspection and testing

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual EXPERTS and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60974-4 has been prepared by IEC technical committee 26: Electric welding. It is an
International Standard.
This fourth edition cancels and replaces the third edition published in 2016. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• examples for the measurements in respect of EN 50699,
• consideration of measuring equipment in respect of IEC 61557 series,
• more determinations of NO-LOAD VOLTAGE for welding equipment built according to
IEC 60974-1:1998 and IEC 60974-1:1998/AMD1:2000 or earlier,

IEC 60974-4:2025 © IEC 2025 – 5 –
• new Annex D providing additional information to be considered when testing battery-
powered WELDING POWER SOURCES and connected chargers.
The text of this International Standard is based on the following documents:
Draft Report on voting
26/769/FDIS 26/777/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The list of all the parts of the IEC 60974 series, under the general title Arc welding equipment,
can be found on the IEC website.
In this document, the following print types are used:
• conformity statements: in italic type.
• terms defined in Clause 3: in SMALL ROMAN CAPITALS.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
– 6 – IEC 60974-4:2025 © IEC 2025
ARC WELDING EQUIPMENT –
Part 4: Periodic inspection and testing

1 Scope
This part of IEC 60974 specifies test procedures for PERIODIC INSPECTION and, after REPAIR, to
ensure electrical safety. These test procedures are also applicable for MAINTENANCE.
This document is applicable to power sources for arc welding and allied processes designed in
accordance with IEC 60974-1 or IEC 60974-6. Stand-alone ancillary equipment designed in
accordance with other parts of IEC 60974 can be tested in accordance with relevant
requirements of this part of IEC 60974.
This document includes requirements for battery-powered ARC WELDING POWER SOURCES, which
are given in Annex D.
NOTE 1 The WELDING POWER SOURCE can be tested with any ancillary equipment fitted that can affect the test
results.
This document is not applicable to testing of new power sources or engine-driven power
sources.
NOTE 2 For a power source not built in accordance with IEC 60974-1, see Annex C.
2 Normative references
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.
IEC 60050-151, International Electrotechnical Vocabulary (IEV) – Part 151: Electrical and
magnetic devices
IEC 60974-1:2021, Arc welding equipment – Part 1: Welding power sources
IEC 60974-6:2015, Arc welding equipment – Part 6: Limited duty equipment
IEC 61140, Protection against electric shock – Common aspects for installation and equipment
IEC 61557-2:2019, Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC – Equipment for testing, measuring or monitoring of protective measures – Part 2:
Insulation resistance
IEC 61557-4:2019, Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC – Equipment for testing, measuring or monitoring of protective measures – Part 4:
Resistance of earth connection and equipotential bonding
IEC 61557-16:2023, Electrical safety in low voltage distribution systems up to 1 000 V AC and
1 500 V DC – Equipment for testing, measuring or monitoring of protective measures – Part 16:
Equipment for testing the effectiveness of the protective measures of electrical equipment
and/or medical electrical equipment

IEC 60974-4:2025 © IEC 2025 – 7 –
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-151,
IEC 60974-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
WELDING POWER SOURCE
ARC WELDING POWER SOURCE
equipment for supplying current and voltage and having the required characteristics suitable
for arc welding and allied processes
Note 1 to entry: A WELDING POWER SOURCE can also supply services to other equipment and auxiliaries for example
auxiliary power, cooling liquid, consumable arc welding electrode and gas to shield the arc and the welding area.
[SOURCE: IEC 60050-851:2008, 851-13-01]
3.2
EXPERT
person who can judge the work assigned and recognize possible hazards on the basis of
professional training, knowledge, experience and knowledge of the relevant equipment
Note 1 to entry: Several years of practice in the relevant technical field may be taken into consideration in
assessment of professional training.
[SOURCE: IEC 60050-851:2008, 851-11-10]
3.3
INSTRUCTED PERSON
person informed about the tasks assigned and about the possible hazards involved in neglectful
behaviour
Note 1 to entry: If necessary, the person has undergone some training.
[SOURCE: IEC 60050-851:2008, 851-11-13]
3.4
PERIODIC INSPECTION
inspection of all equipment, systems and installations carried out on a routine basis
[SOURCE: IEC 60050-426:2020, 426-14-07]
3.5
MAINTENANCE
combination of all technical and management actions intended to retain an item in, or restore it
to, a state in which it can perform as required
Note 1 to entry: Management is assumed to include supervision activities.
[SOURCE: IEC 60050-192:2015, 192-06-01]

– 8 – IEC 60974-4:2025 © IEC 2025
3.6
REPAIR
direct action taken to effect restoration
Note 1 to entry: REPAIR includes fault localization (192-06-19), fault diagnosis (192-06-20); fault correction (192-06-
21); and function checkout (192-06-22).
[SOURCE: IEC 60050-192:2015, 192-06-14]
3.7
NO-LOAD VOLTAGE
voltage, exclusive of any arc striking or arc stabilizing voltage, between the accessible output
terminals of a WELDING POWER SOURCE when the WELDING CIRCUIT is open but energized
[SOURCE: IEC 60050-851:2008, 851-12-24, modified – "but energized" has been added.]
3.8
TOUCH CURRENT
electric current passing through a human body or through livestock when it touches one or
more accessible parts of an installation or of equipment
Note 1 to entry: TOUCH CURRENT is measured by using a measuring network that simulates the impedance of the
human body.
[SOURCE: IEC 60050-195:2021, 195-05-21, modified – A note to entry has been added.]
3.9
VISUAL INSPECTION
inspection by eye to verify that there are no apparent discrepancies with respect to provisions
of the standard concerned
[SOURCE: IEC 60050-851:2008, 851-11-11]
3.10
WELDING CIRCUIT
conductive material through which the WELDING CURRENT is intended to flow
Note 1 to entry: In arc welding, the arc is a part of the WELDING CIRCUIT.
Note 2 to entry: In certain arc welding processes, the welding arc can be established between two electrodes. In
such a case, the workpiece is not necessarily a part of the WELDING CIRCUIT.
[SOURCE: IEC 60050-851:2008, 851-14-10, modified – "may" has been changed to "can".]
3.11
WELDING CURRENT
current delivered by a WELDING POWER SOURCE during welding
Note 1 to entry: This entry revises IEC 60050-851:2008, 851-12-28, which will be updated.

IEC 60974-4:2025 © IEC 2025 – 9 –
3.12
ENVIRONMENT WITH INCREASED RISK OF ELECTRIC SHOCK
environment where the probability of electric shock by arc welding is increased in relation to
normal arc welding conditions
Note 1 to entry: Such environments are found, for example:
a) in locations in which freedom of movement is restricted, so that the operator is forced to perform the welding in
a cramped (for example kneeling, sitting, lying) position with physical contact with conductive parts,
b) in locations which are fully or partially limited by conductive elements, and in
...