IEC 60974-2:2019
(Main)Arc welding equipment - Part 2: Liquid cooling systems
Arc welding equipment - Part 2: Liquid cooling systems
IEC 60974-2:2019 specifies safety and construction requirements for industrial and professional liquid cooling systems used in arc welding and allied processes to cool torches.
This document is applicable to liquid cooling systems which are stand-alone (separate from the welding equipment) or built-in (housed in a single enclosure with other welding equipment).
This fourth edition cancels and replaces the third edition published in 2013 and constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) changes induced by the publication of IEC 60974-1:2017;
b) reference in 11.1 changed.
Matériel de soudage à l'arc - Partie 2: Systèmes de refroidissement par liquide
L'IEC 60974-2:2019 spécifie les exigences de sécurité et de construction des systèmes de refroidissement par liquide industriels et professionnels utilisés en soudage à l'arc et les procédés connexes pour refroidir des torches.
Le présent document s'applique aux systèmes de refroidissement par liquide qui sont indépendants (séparés du matériel de soudage) ou incorporés (intégrés dans une seule enveloppe avec d’autres matériels de soudage).
Cette quatrième édition annule et remplace la troisième édition parue en 2013. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) modifications résultant de la publication de l’IEC 60974-1:2017;
b) référence au 11.1 modifiée.
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Standards Content (Sample)
IEC 60974-2 ®
Edition 4.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 2: Liquid cooling systems
Matériel de soudage à l’arc –
Partie 2: Systèmes de refroidissement par liquide
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IEC 60974-2 ®
Edition 4.0 2019-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Arc welding equipment –
Part 2: Liquid cooling systems
Matériel de soudage à l’arc –
Partie 2: Systèmes de refroidissement par liquide
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.160.30 ISBN 978-2-8322-6497-3
– 2 – IEC 60974-2:2019 © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Environmental conditions . 7
5 Tests . 7
5.1 Test conditions . 7
5.2 Measuring instruments . 7
5.3 Conformity of components . 7
5.4 Type tests . 7
5.5 Routine tests. 7
6 Protection against electric shock . 8
6.1 Insulation . 8
6.1.1 General . 8
6.1.2 Clearances . 8
6.1.3 Creepage distances . 8
6.1.4 Insulation resistance . 8
6.1.5 Dielectric strength . 8
6.2 Protection against electric shock in normal service (direct contact) . 8
6.3 Protection against electric shock in case of a fault condition (indirect
contact) . 8
6.3.1 Protective provisions . 8
6.3.2 Isolation between windings of the supply circuit and the welding circuit . 8
6.3.3 Internal conductors and connections . 8
6.3.4 Touch current in fault condition . 8
6.4 Connection to the supply network . 8
6.4.1 Supply voltage . 8
6.4.2 Multi-supply voltage . 9
6.4.3 Means of connection to the supply circuit . 9
6.4.4 Marking of terminals . 9
6.4.5 Protective circuit . 9
6.4.6 Cable anchorage . 9
6.4.7 Inlet openings . 9
6.4.8 Supply circuit on/off switching device . 9
6.4.9 Supply cables . 9
6.4.10 Supply coupling device (attachment plug) . 9
6.5 Leakage current between welding circuit and protective earth . 9
7 Mechanical provisions . 10
7.1 General . 10
7.2 Cooling liquid overflow . 10
7.3 Hose coupling devices and hose connections . 10
8 Cooling system . 10
8.1 Rated maximum pressure . 10
8.2 Thermal requirements . 11
8.2.1 Heating test . 11
8.2.2 Tolerances of test parameters . 11
8.2.3 Duration of test . 11
8.3 Pressure and temperature . 11
9 Abnormal operation . 11
9.1 General requirements . 11
9.2 Stalled test. 12
10 COOLING POWER . 12
11 Rating plate . 13
11.1 General . 13
11.2 Description . 13
11.3 Contents . 14
11.4 Tolerances . 15
12 Instructions and markings . 15
12.1 Instructions . 15
12.2 Markings . 16
12.2.1 General . 16
12.2.2 Inlet and outlet . 16
12.2.3 Pressure warning . 16
Annex A (informative) Example diagram of built-in and stand-alone LIQUID COOLING
SYSTEMS . 17
Annex B (informative) Example for a rating plate of stand-alone cooling system . 18
Figure 1 – Leakage current measurement configuration . 10
Figure 2 – Measuring circuit for determination of the COOLING POWER . 13
Figure 3 – Principle of the rating plate of stand-alone cooling systems . 14
Figure A.1 – Example diagram of built-in LIQUID COOLING SYSTEMS . 17
Figure A.2 – Example diagram of stand-alone LIQUID COOLING SYSTEMS . 17
Figure B.1 – Single-phase stand-alone cooling unit . 18
Table 1 – Example of cooling liquid data at 60 °C . 13
– 4 – IEC 60974-2:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ARC WELDING EQUIPMENT –
Part 2: Liquid cooling systems
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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indispensable for the correct application of this publication.
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60974-2 has been prepared by IEC technical committee 26:
Electric welding.
This fourth edition cancels and replaces the third edition published in 2013 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) changes induced by the publication of IEC 60974-1:2017;
b) reference in 11.1 changed.
The text of this International Standard is based on the following documents:
FDIS Report on voting
26/670/FDIS 26/675/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this standard, the following print types are used:
– conformity statements: in italic type.
– terms used throughout this standard which have been defined in clause 3: SMALL ROMAN
CAPITALS.
This document shall be used in conjunction with IEC 60974-1:2017.
A list of all parts of IEC 60974, under the general title Arc welding equipment, can be found
on the IEC web site.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 60974-2:2019 © IEC 2019
ARC WELDING EQUIPMENT –
Part 2: Liquid cooling systems
1 Scope
This part of IEC 60974 specifies safety and construction requirements for industrial and
professional LIQUID COOLING SYSTEMS used in arc welding and allied processes to cool torches.
This document is applicable to LIQUID COOLING SYSTEMS which are stand-alone (separate from
the welding equipment) or built-in (housed in a single enclosure with other welding
equipment).
This document is not applicable to refrigerated cooling systems.
NOTE 1 Typical allied processes are electric arc cutting and arc spraying.
NOTE 2 This part of IEC 60974 does not include electromagnetic compatibility (EMC) requirements that are given
in IEC 60974-10.
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 60974-1:2017, Arc welding equipment – Part 1: Welding power sources
IEC 60974-7:2013, Arc welding equipment – Part 7: Torches
IEC 60974-10:2014, Arc welding equipment – Part 10: Electromagnetic compatibility (EMC)
requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60974-1 and
IEC 60974-7 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
cooling power
P
power related to the coolant flow rate and temperature rise
3.2
liquid cooling system
system that circulates and cools liquid used for decreasing the temperature of torches
3.3
cooling power at 1 l/min
P
1 l/min
COOLING POWER at 1 l/min flow rate defined for comparison
4 Environmental conditions
As specified in Clause 4 of IEC 60974-1:2017.
5 Tests
5.1 Test conditions
As specified in 5.1 of IEC 60974-1:2017.
Stand-alone cooling systems may be tested without a welding power source.
Built-in cooling systems shall be tested with the welding power source.
5.2 Measuring instruments
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) thermometer: ± 2 K;
c) pressure measuring instruments: class 2,5 (± 2,5 % of full-scale reading);
d) flow-rate measuring instruments: class 2,5 (± 2,5 % of full-scale reading).
5.3 Conformity of components
As specified in 5.3 of IEC 60974-1:2017.
5.4 Type tests
All type tests shall be carried out on the same cooling system unless specified otherwise.
As a condition of conformity the type tests given below shall be carried out in the following
sequence:
a) general visual inspection (as defined in 3.1.7 of IEC 60974-1:2017);
b) mechanical provisions (as specified in Clause 7);
c) protection provided by the enclosure (as specified in 6.2.1 of IEC 60974-1:2017);
d) insulation resistance (as specified in 6.1.4);
e) dielectric strength (as specified in 6.1.5).
The other tests included in this document and not listed here may be carried out in any
convenient sequence.
5.5 Routine tests
All routine tests given below shall be carried out on each cooling system in the following
sequence:
a) visual inspection in accordance with manufacturer’s specification;
– 8 – IEC 60974-2:2019 © IEC 2019
b) continuity of the protective circuit (as specified in 10.5.3 of IEC 60974-1:2017);
c) dielectric strength (as specified in 6.1.5).
6 Protection against electric shock
6.1 Insulation
6.1.1 General
As specified in 6.1.1 of IEC 60974-1:2017.
6.1.2 Clearances
As specified in 6.1.2 of IEC 60974-1:2017.
6.1.3 Creepage distances
As specified in 6.1.3 of IEC 60974-1:2017.
6.1.4 Insulation resistance
As specified in 6.1.4 of IEC 60974-1:2017.
The test may be carried out without cooling liquid.
6.1.5 Dielectric strength
As specified in 6.1.5 of IEC 60974-1:2017.
The test may be carried out without cooling liquid.
6.2 Protection against electric shock in normal service (direct contact)
As specified in 6.2 of IEC 60974-1:2017.
6.3 Protection against electric shock in case of a fault condition (indirect contact)
6.3.1 Protective provisions
As specified in 6.3.1 of IEC 60974-1:2017.
6.3.2 Isolation between windings of the supply circuit and the welding circuit
As specified in 6.3.2 of IEC 60974-1:2017.
6.3.3 Internal conductors and connections
As specified in 6.3.3 of IEC 60974-1:2017.
6.3.4 Touch current in fault condition
As specified in 6.3.6 of IEC 60974-1:2017.
6.4 Connection to the supply network
6.4.1 Supply voltage
As specified in 10.1 of IEC 60974-1:2017.
6.4.2 Multi-supply voltage
As specified in 10.2 of IEC 60974-1:2017.
6.4.3 Means of connection to the supply circuit
As specified in 10.3 of IEC 60974-1:2017.
6.4.4 Marking of terminals
As specified in 10.4 of IEC 60974-1:2017.
6.4.5 Protective circuit
As specified in 10.5 of IEC 60974-1:2017.
6.4.6 Cable anchorage
As specified in 10.6 of IEC 60974-1:2017.
6.4.7 Inlet openings
As specified in 10.7 of IEC 60974-1:2017.
6.4.8 Supply circuit on/off switching device
As specified in 10.8 of IEC 60974-1:2017.
6.4.9 Supply cables
As specified in 10.9 of IEC 60974-1:2017.
6.4.10 Supply coupling device (attachment plug)
If a supply coupling device is provided as a part of the LIQUID COOLING SYSTEM, its rated values
shall be not less than the maximum effective supply current I .
1eff
For supply networks up to 125 V, the rated current shall, additionally, not be less than either
a) or b):
a) 70 % of the rated maximum supply current;
b) 70 % of the supply current, as measured with the fan motor or pump stalled, whichever is
greater.
Conformity shall be checked by visual inspection, measurement and calculation.
6.5 Leakage current between welding circuit and protective earth
With the cooling system filled with the cooling liquid specified by the manufacturer
(see 12.1 e)), the leakage current from the torch to the protective earth connection of the
cooling system shall not exceed 10 mA DC.
Conformity shall be checked by applying a DC voltage of 500 V at room temperature between
the protective earth connection and a copper pipe to simulate the torch connected to the
outlet of the cooling system by a hose with a maximum length of 0,5 m as shown in Figure 1.
The minimum inner diameter of the hose shall be 5 mm. The minimum length of the copper
pipe shall be 10 cm with a minimum internal diameter of 5 mm. The cooling system and the
simulated torch are filled with liquid for the test. The pump is operating.
– 10 – IEC 60974-2:2019 © IEC 2019
NOTE The design of the torch can influence the leakage current value; therefore, a conventional copper pipe is
used to simulate the torch during the conformity test.
Key
1 LIQUID COOLING SYSTEM
2 Hose
3 Copper pipe
Figure 1 – Leakage current measurement configuration
7 Mechanical provisions
7.1 General
As specified in Clause 14 of IEC 60974-1:2017.
The test shall be carried out with cooling liquid.
7.2 Cooling liquid overflow
When filling the cooling system in accordance with the manufacturer's instructions, overflow
or spillage shall not result in electric shock.
Conformity shall be checked by the following treatment and test. The liquid container is
completely filled. A further quantity of liquid equal to 15 % of the capacity of the container or
0,25 l, whichever is the greater, is then poured in steadily over a period not to exceed 60 s.
Immediately after this treatment, the equipment shall pass the dielectric strength test of 6.1.5
between input circuits and exposed conductive parts.
7.3 Hose coupling devices and hose connections
If hose coupling devices or hose connections, which often have to be undone, are placed
above or near to live parts, these live parts shall be protected from cooling liquid by splash
proof enclosures, with drains or other appropriate measures. An exception is made for live
parts of the welding circuit.
8 Cooling system
8.1 Rated maximum pressure
The manufacturer shall determine the rated maximum pressure attainable by the cooling
system (see 11.3 c), box 12).
Conformity shall be checked by measuring the pressure when the outlet is blocked.
8.2 Thermal requirements
8.2.1 Heating test
LIQUID COOLING SYSTEMS shall be capable of operating at rated COOLING POWER without
causing any component to exceed its rated temperature.
Conformity shall be checked in accordance with Clause 10.
8.2.2 Tolerances of test parameters
+10 %
a) p pressure: p
−2 %
+10 %
b) q volume flow: q
v
v −2 %
c) T temperature: T ± 2 K
8.2.3 Duration of test
As specified in 7.1.3 of IEC 60974-1:2017.
8.3 Pressure and temperature
LIQUID COOLING SYSTEMS shall be capable of operating without leakage at the maximum
pressure with a cooling liquid temperature of 70 °C.
Conformity shall be checked by visual inspection during 120 s of operation or until shutdown
by a protection system, immediately following the heating test while the outlet of the cooling
system is blocked.
9 Abnormal operation
9.1 General requirements
A cooling system shall not break down and increase the risk of electric shock or fire under the
conditions of operation of 9.2. These tests are conducted without regard to temperature
attained on any part, or the continued proper functioning of the cooling system. The only
criterion is that the cooling system does not become unsafe. These tests may be conducted
on any cooling system that functions correctly.
The cooling system, protected internally by, for example, a circuit-breaker or thermal
protection, meets this requirement if the protection device operates before an unsafe
condition occurs.
Conformity shall be checked by the following tests.
a) A layer of dry absorbent surgical type cotton is placed under the cooling system,
extending beyond each side for a distance of 150 mm.
b) Starting from the cold state, the cooling system is operated in accordance with 9.2.
c) During the test, the cooling system shall not emit flames, molten metal or other materials
that ignite the cotton indicator.
d) Following the test and within 5 min, the cooling system shall be capable of withstanding a
dielectric test in accordance with 6.1.5 b) of IEC 60974-1:2017.
– 12 – IEC 60974-2:2019 © IEC 2019
9.2 Stalled test
A cooling system, which relies on motor-driven fan(s) and pump(s) for conformity with the
tests of 8.2, is operated at rated supply voltage or rated load speed for a period of 4 h while
the fan motor(s) and pump(s) is(are) stalled, or running without cooling liquid, or disabled,
which produces the maximum heating.
NOTE The intention of this test is to run the cooling system with the fan stationary. The fan can be blocked
mechanically or disconnected.
10 COOLING POWER
COOLING POWER data shall be given in kW for 100 % duty cycle, with the cooling liquid as
recommended by the manufacturer and at an ambient air temperature at 25 °C (see
tolerances of test parameters in 8.2.2). For these values the volume flow shall be 1 l/min.
This test may be carried out on a separate cooling system.
A built-in cooling system may additionally be heated by the welding power source. Therefore,
the test shall be performed together with the welding power source, set for maximum heating.
This test is not required for LIQUID COOLING SYSTEMS specified by the manufacturer to be used
only with dedicated torches.
Conformity shall be checked by the following test and calculation:
a) the LIQUID COOLING SYSTEM is filled with the amount and type of cooling liquid
recommended in the manufacturer's instructions (see 12.1 e));
b) the LIQUID COOLING SYSTEM is connected to a measuring circuit according to Figure 2;
c) the valve is adjusted to obtain a flow of 1 l/min (see tolerances of test parameters in
8.2.2);
d) the electric heater is adjusted to give a stable condition at a temperature of 65 °C at the
inlet of the LIQUID COOLING SYSTEM (see tolerances of test parameters in 8.2.2);
LIQUID COOLING SYSTEM. Heat
e) the inlet and outlet temperature is measured directly at the
losses of the measuring device should be as low as possible;
f) the test is carried out for a period of not less than 60 min and continued until the rate of
temperature rise does not exceed 2 K/h.
The COOLING POWER is calculated by the following formulae:
P = (T− T ) ××q c q = q ×ρ
v
12 m m
where
P is the COOLING POWER (kW);
T is the temperature of inlet flow (K);
T is the temperature of outlet flow (K);
T – T is the temperature difference (K);
1 2
q is the mass flow (kg/s);
m
q is the volume flow (l/s);
v
c is the specific heat capacity of the cooling liquid (see example in Table 1)(kJ/(kg×K));
ρ is the density of the cooling liquid (see example in Table 1) (kg/l).
Key
1 LIQUID COOLING SYSTEM 4 Thermometer (T ) 7 Electrical heater
2 Inlet flow 5 Adjustable valve 8 Thermometer (T )
3 Outlet flow 6 Flow meter
Figure 2 – Measuring circuit for determination of the COOLING POWER
Table 1 – Example of cooling liquid data at 60 °C
Liquid Specific heat capacity Density
(c)
(ρ)
kJ/(kg × K) kg/l
Water 4,18 0,98
Water/ethanol (50/50) 3,85 0,88
Water/ethylene glycol (50/50) 3,44 1,07
Water/propylene glycol (50/50) 3,69 1,04
Water/ethylene glycol (10/90) 2,67 1,10
Water/propylene glycol (10/90) 2,85 1,02
NOTE 1 Figures in parentheses in column 1 are volume ratios.
NOTE 2 Water is not suitable for the negative temperature range of operating conditions given in Clause 4.
NOTE 3 60 °C is an approximate average temperature of the coolant with a LIQUID COOLING SYSTEM inlet
temperature of 65 °C.
11 Rating plate
11.1 General
As specified in Clause 15.1 of IEC 60974-1:2017.
11.2 Description
The rating plate shall be divided into three sections:
a) identification of stand-alone cooling systems;
b) energy supply of stand-alone cooling systems;
c) LIQUID COOLING SYSTEM.
The arrangement and sequence of the data shall comply with the principle shown in Figure 3
(for an example, see Figure B.1).
– 14 – IEC 60974-2:2019 © IEC 2019
The dimensions of the rating plate are not specified and may be chosen freely.
NOTE Additional information can be given.
In the case of built-in cooling systems, section c) of Figure 3 shall be added to the rating plate
of the welding power source, as specified in Clause 15 of IEC 60974-1:2017.
a) Identification
1)
2) 3)
4)
b) Energy supply
6) 7)
5)
8) 9) If applicable
c) LIQUID COOLING SYSTEM
10) 11) 12)
IEC
Figure 3 – Principle of the rating plate of stand-alone cooling systems
11.3 Contents
a) Identification
Box 1 Name and address of the manufacturer or distributor or importer and, optionally,
a trade mark and the country of origin, if required.
Box 2 Type (identification) as given by the manufacturer.
Box 3 Traceability of design and manufacturing data, for example, serial number.
Box 4 Reference to this part of IEC 60974 confirming that the cooling system complies
with its requirements.
b) Energy supply
Box 5 1(3)~ . Hz Energy supply symbol.
Number of phases (for example, 1 or 3), symbol for
alternating current ~ and the rated frequency (for
example, 50 Hz or 60 Hz).
Box 6 U . V Rated supply voltage.
Box 7 I . A Rated maximum supply current.
1max
Box 8 IP Degree of protection, for example, IP 21 or IP 23.
Box 9 Symbol for class II equipment, if applicable.
c) LIQUID COOLING SYSTEM
Box 10 Symbol for cooling.
Box 11 P . kW Rated COOLING POWER AT 1 l/min of cooling liquid
1 l/min
flow at 25 °C, if required by Clause 10.
In addition, COOLING POWER at different volume flow
values specified by manufacturer may be given.
Box 12 p . Pa (bar) Rated maximum pressure.
max
Conformity shall be checked by visual inspection and by checking of the complete data.
11.4 Tolerances
Manufacturers shall meet rating plate values within the following tolerances by controlling
component and manufacturing tolerances:
a) P COOLING POWER in kW.
The value shall be not less than that stated on the rating plate.
b) p rated maximum pressure in Pa (bar).
max
The value shall be not greater than that stated on the rating plate.
Conformity shall be checked by comparing the values with those stated on the rating plate.
12 Instructions and markings
12.1 Instructions
Each cooling system shall be delivered with instructions including the following, as applicable:
a) general description;
b) mass and correct methods of handling stand-alone LIQUID COOLING SYSTEMS;
c) meaning of indications and graphical symbols;
d) interface requirements for an arc welding power source, for example control power,
control signals, static characteristics and means of connections;
e) recommended cooling liquid and correct operational use of the LIQUID COOLING SYSTEM, for
example cooling conditions, location, pump characteristic, COOLING POWER characteristic,
antifreezes, recommended additives, pressure range, pressure and low water level
sensors, etc.;
f) limitations and explanation of thermal protection, if relevant;
g) limitations related to the degree of protection provided, for example a cooling system with
a degree of protection of IP 21S is not suitable for storage or use in rain or snow;
h) conditions under which extra precautions are to be observed when welding or cutting, for
example environment with increased hazard of electric shock;
LIQUID COOLING SYSTEM;
i) maintenance and service of the
j) a list of parts typically replaced due to wear;
k) warning against the use of non-suitable and conductive cooling liquids and antifreezes;
l) precautions against toppling over, if the LIQUID COOLING SYSTEM shall be placed on a tilted
plane;
m) correct handling and disposal of the cooling liquid;
n) EMC classification in accordance with IEC 60974-10 (stand-alone cooling systems only);
o) correction factor on the COOLING POWER for the ambient temperature of +40 °C.
– 16 – IEC 60974-2:2019 © IEC 2019
Conformity shall be checked by reading the instructions.
12.2 Markings
12.2.1 General
As specified in 17.2 of IEC 60974-1:2017.
12.2.2 Inlet and outlet
The inlet and outlet connections for the cooling liquid shall be clearly and indelibly marked
with the following symbols.
a) Inlet
b) Outlet
Alternatively a colour code may be used
12.2.3 Pressure warning
If the rated maximum pressure of the LIQUID COOLING SYSTEM is higher than 0,5 MPa (5 bar), a
warning shall be attached, for instance:
p X Mpa
max
Annex A
(informative)
Example diagram of built-in and
stand-alone LIQUID COOLING SYSTEMS
Figure A.1 shows an example diagram of built-in LIQUID COOLING SYSTEMS, and Figure A.2 an
example diagram of stand-alone LIQUID COOLING SYSTEMS.
Key
1 Tank 6 Welding circuit
2 Heat exchanger 7 Welding transformer
3 Pump 8 Transformer
4 Grounded cooling liquid pipes 9 Contact tip
5 Torch
Figure A.1 – Example diagram of built-in LIQUID COOLING SYSTEMS
Key
1 Tank 5 Torch
2 Heat exchanger 6 Welding circuit
3 Pump 9 Contact tip
4 Grounded cooling liquid pipes
Figure A.2 – Example diagram of stand-alone LIQUID COOLING SYSTEMS
– 18 – IEC 60974-2:2019 © IEC 2019
Annex B
(informative)
Example for a rating plate of stand-alone cooling system
a) Identification
1) Manufacturer Trademark
Address
2) Type 3) Serial No.
4) IEC 60974-2
b) Energy supply
6) U = 230 V 7) I = 1,2 A
5) 1 1max
8) IP 23S 9) —
1~ 50 Hz
c) LIQUID COOLING SYSTEM
11) P = 0,55 kW 12) p = 0,38 MPa
1 l/min max
10)
IEC
Figure B.1 – Single-phase stand-alone cooling unit
___________
– 20 – IEC 60974-2:2019 © IEC 2019
SOMMAIRE
AVANT-PROPOS . 22
1 Domaine d’application . 24
2 Références normatives . 24
3 Termes et définitions . 24
4 Conditions ambiantes . 25
5 Essais . 25
5.1 Conditions d'essai . 25
5.2 Instruments de mesure . 25
5.3 Conformité des composants . 25
5.4 Essais de type . 25
5.5 Essais individuels de série . 26
6 Protection contre les chocs électriques . 26
6.1 Isolement . 26
6.1.1 Généralités . 26
6.1.2 Distances d’isolement dans l'air . 26
6.1.3 Lignes de fuite . 26
6.1.4 Résistance d'isolement . 26
6.1.5 Rigidité diélectrique . 26
6.2 Protection contre les chocs électriques en service normal (contact direct) . 26
6.3 Protection contre les chocs électriques en cas de défaut (contacts indirects) . 26
6.3.1 Mesures de protection . 26
6.3.2 Isolation entre les enroulements du circuit d'alimentation et le circuit de
soudage . 26
6.3.3 Conducteurs et connexions internes . 26
6.3.4 Courant de contact en cas de défaut . 27
6.4 Raccordement au réseau d'alimentation . 27
6.4.1 Tension d'alimentation . 27
6.4.2 Tension d'alimentation multiple . 27
6.4.3 Moyens de raccordement au circuit d'alimentation . 27
6.4.4 Marquage des bornes . 27
6.4.5 Circuit de protection . 27
6.4.6 Serre-câble .
...
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