IEC 60974-6:2010

IEC 60974-6
®
Edition 2.0 2010-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Arc welding equipment –
Part 6: Limited duty equipment

Matériel de soudage à l’arc –
Partie 6: Matériel à service limité

IEC 60974-6:2010

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IEC 60974-6
®
Edition 2.0 2010-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside


Arc welding equipment –
Part 6: Limited duty equipment

Matériel de soudage à l’arc –
Partie 6: Matériel à service limité

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
W
CODE PRIX
ICS 25.160.30 ISBN 978-2-88912-265-3
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – 60974-6 Ó IEC:2010
CONTENTS
FOREW ORD . 6
1 Sc o pe . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Environmental conditions. 10
5 Tests . 10
5.1 Test conditions . 10
5.2 Measuring instruments. 10
5.3 Conformity of components. 10
5.4 Type tests . 10
5.5 Routine tests . 11
6 Protection against electric shock . 11
6.1 Insulation . 11
6.1.1 General . 11
6.1.2 Clearances . 11
6.1.3 Creepage distances. 11
6.1.4 Insulation resistance. 12
6.1.5 Dielectric strength . 12
6.2 Protection against electric shock in normal service (direct contact). 12
6.2.1 Protection provided by the enclosure . 12
6.2.2 Capacitors . 12
6.2.3 Automatic discharge of input capacitors . 13
6.3 Protection against electric shock in case of a fault condition (indirect contact) . 13
6.3.1 Protective provisions . 13
6.3.2 Isolation of the supply circuit and the welding circuit . 13
6.3.3 Insulation between windings of the supply circuit and the welding
circuit . 13
6.3.4 Internal conductors and connections . 13
6.3.5 Additional requirements for plasma cutting systems . 13
6.3.6 Movable coils and cores. 13
6.3.7 Touch current in fault condition . 13
7 Thermal requirements . 15
7.1 Devices for thermal protection and thermal control . 15
7.2 Heating test . 15
7.2.1 Test conditions . 15
7.2.2 Tolerances of the test parameters . 15
7.2.3 Rated maximum welding current . 15
7.2.4 Calculation . 16
7.3 Temperature measurement . 16
7.3.1 Measurement condition . 16
7.3.2 Surface temperature sensor . 16
7.3.3 Resistance . 16
7.3.4 Embedded temperature sensor . 16
7.3.5 Determination of the ambient air temperature . 16
7.3.6 Recording of temperatures . 16
7.4 Limits of temperature . 16

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60974-6 Ó IEC:2010 – 3 –
7.4.1 Windings, commutators and slip-rings . 16
7.4.2 External surfaces . 17
7.4.3 Other components . 17
7.5 Loading test . 17
7.6 Commutators and slip-rings . 17
8 Thermal control device . 18
8.1 Construction . 18
8.2 Location . 18
8.3 Operation . 18
8.4 Resetting . 18
8.5 Operating capacity . 18
8.6 Indication . 18
9 Thermal protection . 19
9.1 Construction . 19
9.2 Location . 19
9.3 Operation . 19
10 Abnormal operation . 19
10.1 General requirements . 19
10.2 Stalled fan test. 20
10.3 Short circuit test . 20
10.4 Overload test . 20
11 Connection to the input supply network . 20
11.1 Input supply . 20
11.1.1 Supply voltage . 20
11.1.2 Supply current . 20
11.1.3 Engine driven welding power source . 20
11.2 Multi supply voltage . 21
11.3 Means of connection to the supply circuit . 21
11.4 Supply circuit terminals . 21
11.5 Cable anchorage . 21
11.6 Inlet openings . 21
11.7 Supply circuit on/off switching device . 21
11.8 Supply cables . 21
11.9 Supply coupling device (attachment plug) . 21
12 Output . 22
12.1 Rated no-load voltage . 22
12.1.1 Rated no-load voltage for arc welding power source . 22
12.1.2 Rated no-load voltage for plasma cutting power source . 22
12.1.3 Additional requirements . 23
12.1.4 Measuring circuit . 23
12.2 Type test values of the conventional load voltage . 25
12.2.1 Manual metal arc welding with covered electrodes . 25
12.2.2 Tungsten inert gas . 25
12.2.3 Metal inert/active gas and flux cored arc welding . 25
12.2.4 Plasma cutting . 25
12.2.5 Additional requirements . 25
12.3 Mechanical switching devices used to adjust output . 25
12.4 Welding circuit connections . 25

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– 4 – 60974-6 Ó IEC:2010
12.4.1 Protection against unintentional contact . 25
12.4.2 Location of coupling devices . 25
12.4.3 Outlet openings. 25
12.4.4 Marking . 25
12.4.5 Connections for plasma cutting torches . 25
12.5 Power supply to external devices . 25
12.6 Auxiliary power output . 26
12.7 Welding cables . 26
13 Control circuits . 26
14 Hazard reducing device . 26
15 Mechanical provisions . 27
15.1 General requirements . 27
15.2 Enclosure . 27
15.2.1 Enclosure materials . 27
15.2.2 Enclosure strength . 27
15.3 Handling means . 27
15.4 Drop withstand . 27
15.5 Tilting stability . 27
16 Auxiliaries . 27
16.1 General . 27
16.2 Wire feeder . 27
16.2.1 General . 27
16.2.2 Test conditions . 27
16.2.3 Thermal requirements . 27
16.2.4 Protection against unintentional contact . 27
16.3 Torch . 28
16.3.1 General . 28
16.3.2 Test conditions . 28
16.3.3 Thermal requirements . 28
16.4 Electrode holder. 28
16.5 Pressure regulator . 28
17 Rating plate . 28
17.1 General requirements . 28
17.2 Description . 28
17.3 Contents . 29
17.4 Tolerances . 31
18 Adjustment of the output . 31
19 Instructions and markings . 31
19.1 Instructions . 31
19.1.1 General . 31
19.1.2 Instruction manual . 32
19.1.3 Safety instructions . 32
19.2 Markings . 33
Annex A (informative) Test probes . 34
Annex B (informative) Examples of rating plates . 35
Annex C (informative) Symbols-only precautionary label . 36
Bibliography . 37

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60974-6 Ó IEC:2010 – 5 –

Figure 1 – Measurement of touch current in fault condition . 14
Figure 2 – Measuring network for weighted touch current . 14
Figure 3 – Measurement of r.m.s values . 24
Figure 4 – Measurement of peak values . 24
Figure 5 – Principle of the rating plate . 29
Figure A.1 – Test probe 12 of IEC 61032 . 34
Figure A.2 – Test probe 13 of IEC 61032 . 34
Figure B.1 – Rating plate . 35
Figure C.1 – Example of precautionary label for engine driven manual metal arc
welding power sourceBibliography . 36

Table 1 – Temperature limits according to the class of insulation. 17
Table 2 – Summary of rated no-load voltages . 23
Table 3 – Hazard reducing device requirements for plasma cutting power source . 26

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– 6 – 60974-6 Ó IEC:2010
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ARC WELDING EQUIPMENT –

Part 6: Limited duty equipment


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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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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
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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 60974-6 has been prepared by IEC technical committee 26:
Electric welding.
This second edition cancels and replaces the first edition published in 2003. It constitutes a
technical revision.
The main significant technical changes with respect to the previous edition are the following:
– extension of the scope;
– amendment of the title;
– touch current at fault condition (see 6.3.7);
– new definition of thermal requirements based two independent devices, one for thermal
protection and one for thermal control (see 7.1);
– new definition for thermal performances at 20 °C (see 7.2);
– thermal safety requirements are based on operating temperature for normal condition and
maximum temperature in overload condition (see 7.4);

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60974-6 Ó IEC:2010 – 7 –
– addition of abnormal operation test for thermal control device (see 10.4);
– new requirement for auxiliaries (see Clause 16);
– new rating plate definition (see Clause 17);
– introduction of new mandatory warning symbols (see 12.1.117.3, Box 17b) and 19.2);
– induced changes due to publication of IEC 60974-1:2005.
The text of this standard is based on the following documents:
FDIS Report on voting
26/429/FDIS 26/437/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.
This standard is to be used in conjunction with IEC 60974-1:2005.
In this standard, the following print types are used:
– conformity statements: in italic type.
A list of all the parts in the IEC 60974 series, published under the general title Arc welding
equipment, can be found on the IEC website.
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.

IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

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– 8 – 60974-6 Ó IEC:2010
ARC WELDING EQUIPMENT –

Part 6: Limited duty equipment



1 Scope
This part of IEC 60974 specifies safety and performance requirements applicable to limited
duty arc welding and cutting power sources, and auxiliaries designed for use by laymen.
Electrically powered equipment is intended to be connected to the single phase public low-
voltage supply system. Engine driven power sources can not exceed output power of 7,5 kVA.
NOTE 1 This equipment is typically used by non-professionals in residential areas.
This part of IEC 60974 is not applicable to arc welding and cutting power sources that require
for operation:
· arc striking and stabilizing devices;
· liquid cooling systems;
· gas consoles;
· three-phase input supply;
and which are intended for industrial and professional use only.
This part of IEC 60974 is not applicable to arc welding and cutting power sources and
ancillary equipment used in:
...