IEC 60974-12:2011

Arc welding equipment - Part 12: Coupling devices for welding cables

IEC 60974-12:2011 is applicable to coupling devices for cables used in arc welding and allied processes, designed for connection and disconnection without using tools. This part of IEC 60974 specifies safety and performance requirements of coupling devices. This part of IEC 60974 is not applicable to coupling devices for underwater welding. This third edition cancels and replaces the second edition published in 2005. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- dimensions given in Annex A become normative,
- designation is based on the range of cross-sectional area of the welding cable intended to be connected.

Matériel de soudage à l'arc - Partie 12: Dispositifs de connexion pour câbles de soudage

La CEI 60974-12:2011 s'applique aux dispositifs de connexion pour câbles utilisés lors du soudage et des techniques connexes conçus pour assurer les opérations de connexion et de déconnexion sans emploi d'outils. La présente partie de la CEI 60974 spécifie les exigences de sécurité et de performance pour les dispositifs de connexion. Cette partie de la CEI 60974 ne s'applique pas aux dispositifs de connexion utilisés pour le soudage sous l'eau. Cette troisième édition annule et remplace la deuxième édition parue en 2005. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- les dimensions données en Annexe A deviennent normative,
- la désignation est basée sur la plage de la section du câble de soudage prévue pour être connectée.

General Information

• Status: Published
• Publication Date: 17-May-2011
• ICS: 25.160.30 - Welding equipment
• Technical Committee: TC 26 - Electric welding
• Drafting Committee: WG 1 - TC 26/WG 1
• Current Stage: DELPUB - Deleted Publication
• Start Date: 08-Jul-2022
• Completion Date: 15-Oct-2021

Relations

• Revises: IEC 60974-12:2005 - Arc welding equipment - Part 12: Coupling devices for welding cables
• Effective Date: 05-Sep-2023
• Revised: IEC 60974-12:2022 - Arc welding equipment - Part 12: Coupling devices for welding cables
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60974-12 ®
Edition 3.0 2011-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 12: Coupling devices for welding cables

Matériel de soudage à l’arc –
Partie 12 : Dispositifs de connexion pour câbles de soudage

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IEC 60974-12 ®
Edition 3.0 2011-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 12: Coupling devices for welding cables

Matériel de soudage à l’arc –
Partie 12 : Dispositifs de connexion pour câbles de soudage

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX M
ICS 25.160.30 ISBN 978-2-88912-502-9

– 2 – 60974-12  IEC:2011
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Environmental conditions . 6
5 Type tests . 6
5.1 Test conditions . 6
5.2 Test sequence . 6
6 Designation . 6
7 Protection against electric shock . 7
7.1 Voltage rating . 7
7.2 lnsulation resistance . 7
7.3 Dielectric strength . 8
7.3.1 General requirement . 8
7.3.2 Additional requirements for striking and stabilizing voltage rating . 8
7.4 Protection of live parts against unintentional contact . 8
8 Thermal rating . 9
8.1 Temperature rise . 9
8.2 Resistance to hot objects . 9
9 Mechanical requirements . 10
9.1 Retaining means . 10
9.2 Welding cable entry . 10
9.3 Penetration of the welding cable insulation . 10
9.4 Welding cable connection . 10
9.5 Crush strength. 10
9.6 Dimensions . 11
10 Marking . 11
11 Instructions for use . 11
Annex A (normative) Dimensions . 12

Figure 1 – Device for testing the resistance to hot objects . 9
Figure A.1 – Male element . 12
Figure A.2 – Female element . 12

Table 1 – Relation between coupling device test current and welding cables' cross-
sectional area . 7
Table 2 – Voltage rating of coupling devices . 7
Table 3 – Crush force . 11
Table A.1 – Dimensions for Figures A.1 and A.2 . 13

60974-12  IEC:2011 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ARC WELDING EQUIPMENT –
Part 12: Coupling devices for welding cables

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
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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) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60974-12 has been prepared by IEC technical committee 26:
Electric welding.
This third edition cancels and replaces the second edition published in 2005. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
• dimensions given in Annex A become normative;
• designation is based on the range of cross-sectional area of the welding cable intended to
be connected.
– 4 – 60974-12  IEC:2011
The text of this standard is based on the following documents:
FDIS Report on voting
26/441/FDIS 26/446/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60974 series can be found, under the general title Arc welding
equipment, on the IEC website.
In this standard, the following print types are used:
- conformity statements: in italic type.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
60974-12  IEC:2011 – 5 –
ARC WELDING EQUIPMENT –
Part 12: Coupling devices for welding cables

1 Scope
This part of IEC 60974 is applicable to coupling devices for cables used in arc welding and
allied processes, designed for connection and disconnection without using tools.
This part of IEC 60974 specifies safety and performance requirements of coupling devices.
This part of IEC 60974 is not applicable to coupling devices for underwater welding.
2 Normative references
The following referenced documents are indispensable for the application 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 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60974-1, Arc welding equipment – Part 1: Welding power sources
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the IEC 60050-151, the
IEC 60974-1, as well as the following apply.
3.1
coupling device
device connecting two welding cables together or connecting a welding cable to welding
equipment
3.2
retaining means
mechanical arrangement that holds the coupling device in position and prevents an
unintentional withdrawal, when properly connected
3.3
arc striking and stabilizing voltage
voltage superimposed on the welding circuit to initiate or maintain the arc

– 6 – 60974-12  IEC:2011
4 Environmental conditions
The coupling device shall be capable of operation when the following environmental
conditions prevail:
a) range of ambient air temperature:
– during operation: –10 °C to + 40 °C;
b) relative humidity of the air: up to 90 % at 20 °C.
The coupling device shall withstand storage and transport at an ambient air temperature
of –20 °C to + 55 °C without any damage to function and performance.
5 Type tests
5.1 Test conditions
All type tests shall be carried out on the same new and completely assembled coupling
device.
All type tests shall be carried out at an ambient air temperature between 10 °C and 40 °C.
The accuracy of measuring instruments shall be:
a) electrical measuring instruments: class 1 (± 1 % of full-scale reading), except for the
measurement of insulation resistance and dielectric strength where the accuracy of the
instruments is not specified, but shall be taken into account for the measurement;
b) temperature measuring devices: ± 2 K.
5.2 Test sequence
The type tests given below shall be carried out in the following sequence:
a) general visual inspection;
b) temperature rise, see 8.1;
c) crush strength, see 9.5;
d) insulation resistance, see 7.2;
e) dielectric strength, see 7.3.
The other type tests in this part of IEC 60974 not mentioned above may be carried out in any
convenient sequence.
6 Designation
Coupling devices shall be designated by the range of cross-sectional area of the welding
cable intended to be connected. The test current at an ambient air temperature of 40 °C is
given in Table 1 based on maximum cross-section area. The welding coupling device shall
accept the minimum cross-sectional area as given in Table 1. Minimum cross-sectional area
may be reduced to extend the coupling device fitting range.

60974-12  IEC:2011 – 7 –
Table 1 – Relation between coupling device test current
and welding cables' cross-sectional area
Range of cross-sectional area Coupling device test current at
60 % duty cycle
mm
A
up to 10 125
10 to 16 150
16 to 25 200
25 to 35 250
35 to 50 300
50 to 70 400
70 to 95 500
NOTE Welding cables are rated based on cross-sectional area. Test
current is defined in order that coupling device withstands the rated
current of the welding cable.
Conformity shall be checked by measurement.
7 Protection against electric shock
7.1 Voltage rating
Coupling devices shall be rated in accordance with the process as given in Table 2 and the
arc striking and stabilizing voltage if applicable.
Table 2 – Voltage rating of coupling devices
Degree of
Insulation
Voltage rating Dielectric strength
protection in
resistance
Process
accordance with
V peak V r.m.s.
MΩ
IEC 60529
All processes except
113 2,5 1 000 IP 3X
plasma cutting
Plasma cutting 500 2,5 2 100 IP 3X

7.2 lnsulation resistance
The insulation resistance of a new coupling device shall, after the humidity treatment, be not
less than 2,5 MΩ.
Conformity shall be checked by the following test.
a) Humidity treatment
A humidity cabinet is maintained at a temperature t between 20 °C and 30 °C and a
relative humidity between 91 % and 95 %.
The coupling device without cables fitted is brought to a temperature between t and t + 4 K
and is then placed for 48 h in the humidity cabinet.
b) Insulation resistance measurement
Immediately after the humidity treatment, the coupling device is wiped clean and tightly
wrapped in a metal foil covering the external surface of the insulation.

– 8 – 60974-12  IEC:2011
The insulation resistance is measured by application of a d.c. voltage of 500 V between
the live parts and the metal foil, the reading being made after stabilization of the
measurement.
7.3 Dielectric strength
7.3.1 General requirement
The insulation shall withstand an a.c. test voltage of 1 000 V r.m.s. without flashover or
breakdown. Any discharges unaccompanied by a voltage drop are disregarded.
Conformity shall be checked by the following test.
The coupling device is wiped clean and tightly wrapped in a metal foil covering the external
surface of the insulation.
The a.c. test voltage shall be of an approximate sine waveform with a peak value not
exceeding 1,45 times the r.m.s. value, having a frequency of 50 Hz or 60 Hz, applied for 1 min
between the live parts and the metal foil.
7.3.2 Additional requirements for striking and stabilizing voltage rating
For couplers for use with arc striking and stabilizing voltage, the insulation shall withstand the
rated peak arc striking and stabilizing voltage as rated by the manufacturer. The insulation
shall withstand a high frequency voltage of pulse width 0,2 μs to 8 μs, a repetition frequency
of 50 Hz to 300 Hz and shall be 20 % higher than the rated peak arc striking and stabilizing
voltage as determined by the manufacturer.
Conformity shall be checked by the following test.
For couplers intended for use with arc striking and stabilizing voltage, the couplers shall be
subjected to the high-frequency test voltage. The full value of the high-frequency voltage is
applied for 2 s between the electrode circuit and
a) conductive surfaces;
b) other isolated circuits.
Flashover or breakdown shall not occur. Any discharges unaccompanied by a voltage drop
(corona) are disregarded.
Alternatively, for couplers intended for use with arc striking and stabilizing voltage, an a.c.
test voltage of approximately sine waveform at 50 Hz or 60 Hz may be used.
7.4 Protection of live parts against unintentional contact
Parts designed to carry welding current and likely to be live after disconnection shall be
recessed to a depth of at least 10 % of the internal diameter of the insulation with a minimum
depth of 2 mm with respect to the insulating body.
As a consequence, insulation has to be able to withstand normal service conditions so that
the protecting length is maintained during the life of the coupling device.
Conformity shall be checked by linear measurement and visual inspection.

60974-12  IEC:2011 – 9 –
8 Thermal rating
8.1 Temperature rise
The temperature rise caused by the current passing through a coupling device normally
coupled and fitted with an untinned copper welding cable of maximum cross-sectional area as
indicated in Table 1 shall not exceed 45 K at the hottest spot of the external surface.
Conformity shall be checked by the following test.
The coupling device is normally coupled and fitted with at least 2 m long welding cables. The
coupling device is suspended by its welding cables from two wooden laths 1 m apart, hanging
between the two laths in the horizontal plane about 200 mm above the ground in a draught-
free area.
A continuous d.c. current equal to 75 % of the test current (equivalent to approximately 60 %
duty cycle) is passed through the coupling device until the rate of the temperature rise does
not exceed 2 K/h. During the total test time, the d.c. current shall be kept constant with a
tolerance of ± 2 %.
8.2 Resistance to hot objects
The insulation shall be capable of withstanding hot objects and the effects of a normal amount
of weld spatter without being ignited or becoming unsafe.
Conformity shall be checked with a device in accordance with Figure 1.

θ
∅2,5 ± 0,05
F
1 2
+0,2
F = 1    N
100 ± 0,5
IEC  784/05
Key
Dimensions in millimetres
1 18/8 chrome-nickel steel
θ test temperature
2 coupling device
Figure 1 – Device for testing the resistance to hot objects
An electric current (of approximately 25 A) is passed through the rod until a steady-state
+5
temperature θ of 300 °C is reached. During the test, the temperature of the heated rod
shall be maintained. This temperature will be measured by a contact thermometer or
thermocouple.
The heated rod in a horizontal position is then applied for 2 min to the insulation at the
weakest point (for example, minimum insulation thickness and closest distance to live parts).
The heated rod shall not penetrate through the insulation and contact live parts.

– 10 – 60974-12  IEC:2011
An attempt is made to ignite any gases which may be emitted in the region of the contact
point by means of an electric spark or small flame. If the gases are flammable, the burning
shall stop as soon as the heated rod is removed.
9 Mechanical requirements
9.1 Retaining means
A retaining means shall be provided to prevent the unintentional separation of the coupling
device as a result of a longitudinal pull.
NOTE If possible, indicating marks, for example two lines opposite each other, should show by visual inspection
that the retaining means has functioned.
Conformity shall be checked by manual operation and visual inspection.
9.2 Welding cable entry
The cable entries of cable couplers shall be designed so as to prevent damage to the cable
due to flexing.
Conformity shall be checked by visual inspection.
9.3 Penetration of the welding cable insulation
The design of cable couplers shall be such that the insulation of the cables can enter to a
depth of at least twice the outer diameter of the welding cable with a minimum of 30 mm.
Conformity shall be checked by measurement with a welding cable of the maximum cross-
sectional area as specified by the manufacturer.
9.4 Welding cable connection
The design of the coupling device shall be such that welding cables with a cross-sectional
area within the range as specified by the manufacturer can be replaced. The connection shall
withstand the mechanical stress of the tensile test without separation.
Conformity shall be checked by visual inspection and by the following test.
A plug, a connector or a plug connector is fitted in accordance with the manufacturer’s
instructions, with a welding cable of maximum cross-sectional area. The connection is
subjected to 10 pulls with a force of 40 N/mm² of the cross-sectional area with a maximum of
2 000 N applied to the welding cable. The force of each pull is gradually increased from zero
to the specified value in 1 s and maintained for 1 s.
After the test, the conductor shall not have been noticeably displaced.
This test shall be repeated with a welding cable having the minimum permissible cross-
sectional area as specified by the manufacturer.
If more than one method of cable fixing is provided, all methods shall be tested.
9.5 Crush strength
Coupling devices shall withstand the mechanical stress of the crush test without the insulation
being destroyed or the mechanical functioning being impaired.
Conformity shall be checked by the following test, manual operation and visual inspection.

60974-12  IEC:2011 – 11 –
A cable coupler connected and fitted, in accordance with the manufacturer’s instructions, with
welding cables of maximum cross-sectional area is placed between the parallel plates of a
press, the axis of the cable coupler being at a right angle to the direction of the crush force.
The crush force is applied and gradually increased up to the values given in Table 3.
Table 3 – Crush force
Cross-sectional area of welding cable Crush force
mm N
up to 25 1 200
25 to 50 1 500
above 50 2 000
This test shall be repeated with a welding cable of minimum cross-sectional area as specified
by the manufacturer.
9.6 Dimensions
Coupling devices shall be designed in accordance with dimensions given in Annex A.
10 Marking
The following information shall be legibly and indelibly marked on coupling devices designed
to be attached to welding cables:
a) name of the manufacturer, distributor, importer or the registered trademark;
b) maximum permissible cross-sectional area of the welding cable;
c) minimum permissible cross-sectional area of the welding cable;
d) rated peak arc striking and stabilizing voltage if applicable;
e) reference to this part of IEC 60974, confirming that the coupling device complies with the
requirements.
For coupling devices having a maximum permissible cross-sectional area less than or equal
to 16 mm², the dimensions of which are such that it is not possible to put on all the markings
clearly, item c) can be omitted and shown on the packing or in the literature.
Coupling devices designed to be mounted on a panel need not be marked.
Conformity shall be checked by reading the marking.
11 Instructions for use
Each coupling device shall be delivered with an instruction sheet which includes the following
information:
a) correct coupling and uncoupling of the coupling device;
b) correct connection of the welding cable;
c) choice of welding cable, type and size;
d) relation of permissible current and duty cycle
...