SIST EN ISO 5826:2003

SLOVENSKI STANDARD
SIST EN ISO 5826:2003
01-december-2003
Oprema za elektrouporovno varjenje - Transformatorji - Splošne specifikacije,
veljavne za vse transformatorje (ISO 5826:1999)
Resistance welding equipment - Transformers - General specifications applicable to all
transformers (ISO 5826:1999)
Widerstandsschweißeinrichtungen - Transformatoren - Allgemeine Anforderungen (ISO
5826:1999)
Matériel de soudage par résistance - Transformateurs - Spécifications générales
applicables a tous les transformateurs (ISO 5826:1999)
Ta slovenski standard je istoveten z: EN ISO 5826:2003
ICS:
25.160.30 Varilna oprema Welding equipment
29.180 Transformatorji. Dušilke Transformers. Reactors
SIST EN ISO 5826:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 5826:2003

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SIST EN ISO 5826:2003
EUROPEAN STANDARD
EN ISO 5826
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2003
ICS 25.160.30; 29.180
English version
Resistance welding equipment - Transformers - General
specifications applicable to all transformers (ISO 5826:1999)
Matériel de soudage par résistance - Transformateurs - Widerstandsschweißeinrichtungen - Transformatoren -
Spécifications générales applicables à tous les Allgemeine Anforderungen (ISO 5826:1999)
transformateurs (ISO 5826:1999)
This European Standard was approved by CEN on 3 April 2003.
CEN 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 Management Centre or to any CEN 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 CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5826:2003 E
worldwide for CEN national Members.

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SIST EN ISO 5826:2003
EN ISO 5826:2003 (E)
Foreword
The text of ISO 5826:1999 has been prepared by Technical Committee ISO/TC 44 "Welding and
allied processes" of the International Organization for Standardization (ISO) and has been taken
over as EN ISO 5826:2003 by Technical Committee CEN/TC 121 "Welding", the secretariat of
which is held by DS.
This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by November 2003, and conflicting national
standards shall be withdrawn at the latest by November 2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and
the United Kingdom.
Endorsement notice
The text of ISO 5826:1999 has been approved by CEN as EN ISO 5826:2003 without any
modifications.
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SIST EN ISO 5826:2003
INTERNATIONAL ISO
STANDARD 5826
Second edition
1999-11-15
Resistance welding equipment —
Transformers — General specifications
applicable to all transformers
Matériel de soudage par résistance — Transformateurs — Spécifications
générales applicables à tous les transformateurs
A
Reference number
ISO 5826:1999(E)

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SIST EN ISO 5826:2003
ISO 5826:1999(E)
Contents Page
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Symbols.2
5 Physical environment and operating conditions.3
6 Test conditions .3
7 Protection against electric shock.5
8 Thermal requirements.6
9 Rated no-load output voltage (U ) .9
20
10 Rated short-circuit voltage (U ).9
cc
11 Cooling liquid circuit .9
12 Dynamic behaviour.10
13 Rating plate .10
14 Instruction manual.12
Annex A (informative) Example of a rating plate.13
Annex B (normative) Corrections for higher altitudes and cooling medium temperatures .14
Annex C (normative) Notes on physical concepts and comments on some definitions.15
Annex D (normative) Type code .21
Bibliography.22
©  ISO 1999
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet iso@iso.ch
Printed in Switzerland
ii

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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO 5826 was prepared by Technical Committee ISO/TC 44, Welding and allied processes,
Subcommittee SC 6, Resistance welding.
This second edition cancels and replaces the first edition (ISO 5826:1983), which has been technically revised.
Annexes B, C and D form a normative part of this International Standard. Annex A is for information only.
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SIST EN ISO 5826:2003

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SIST EN ISO 5826:2003
INTERNATIONAL STANDARD  © ISO ISO 5826:1999(E)
Resistance welding equipment — Transformers — General
specifications applicable to all transformers
1 Scope
This International Standard give specifications applicable to transformers for resistance welding equipment without
connected rectifier.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 669, Resistance welding equipment — Mechanical and electrical requirements.
IEC 60051-2, Direct acting indicating analogue electrical measuring instruments and their accessories — Part 2:
Special requirements for ammmeters and voltmeters.
IEC 60085, Thermal evaluation and classification of electrical insulation.
IEC 60204-1, Electrical equipment of industrial machines — Part 1: General requirements.
IEC 60529, Degrees of protection provided by enclosures (IP code).
IEC 60536-2, Classification of electrical and electronic equipment with regard to protection against electric shock —
Part 2: Guidelines to requirements for protection against electric shock.
IEC 60664-1, Insulation coordination for equipment within low-voltage systems — Part 1: Principles, requirements
and tests.
IEC 60905, Loading guide for dry-type power transformers.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 669 apply.
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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
4 Symbols
The symbols used in this International Standard are listed in Table 1.
Table 1 — List of symbols
Symbol Description Reference
I rated permanent input current 10, 12
1
p
I input current at a given duty factor annex C
1
X
I output current annex C
2
I permanent output current at 100 % duty factor 13.2, annex C
2
p
I output current at a given duty factor annex C
2
X
I output current at 50 % duty factor 13.2
2/50
m mass 13.2
P power annex C
P permanent input power (at 100 % duty factor) 10, 11, 13.2, annex C
p
P input power at a given duty factor annex C
X
P input power at 50 % duty factor 13.2
50
Q required total rate of cooling liquid flow 11, 13.2
R initial resistance of a winding 8.2.1, 8.3.2
1
R resistance of a winding at the end of the heating test 8.3.2
2
t time annex C
t on-load time annex C
1
T cycle time annex C
U rated short-circuit voltage 10
cc
U input short-circuit voltage 10
1
cc
U rated supply voltage 9, 10, 13.2
1N
U rated output no-load voltage 9, 13.2
20
X duty factor annex C
X duty factor of the magnetic circuit annex C
m
Z total impedance refered to the output 10
2
Dp pressure drop of the cooling liquid circuit 11, 13.2
Du temperature differences annex C
1, 2
u temperature annex C
u cooling medium temperature annex C
a
u equilibrium temperature annex C
m
u temperature when the transformer starts to cool annex C
n
temperatures for calculation of the thermal time constant or the
u 8.2.1, 8.3.2, annex C
0, 1, 2
winding temperatures during the heating test
t thermal time constant annex C
t thermal time constant at given on-load time annex C
2
t thermal time constant at permanent output current annex C
2
p
2

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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
5 Physical environment and operating conditions
5.1 General
Transformers shall be suitable for use in the physical environment and operating conditions as specified below.
When the physical environment and/or operating conditions are outside those specified below, an agreement may
be needed between the supplier and the user, (see e.g. annex B of IEC 60204-1:1997).
5.2 Ambient air temperature
Transformers shall be capable of operating correctly in an ambient air temperature between 1 5 °C and 1 40 °C.
In case of other maximum temperatures of the cooling medium, see annex B.
5.3 Humidity
Transformers shall be capable of operating correctly within a relative humidity range of 30 % to 95 %.
Harmful effects of occasional condensation shall be avoided by proper design of the equipment or, where
necessary, by proper additional measures (e.g. air conditioners, drain holes).
5.4 Altitude
Transformers shall be capable of operating correctly at altitudes up to 1 000 m above mean sea level.
In case of other altitudes, see annex B.
5.5 Transportation and storage
Transformers shall be designed to withstand, or suitable precautions shall be taken to protect against, transportation
and storage temperatures between 2 25 °C and 1 55 °C and for short periods not exceeding 24 h up to 1 70 °C.
Suitable means shall be provided to prevent damage from humidity, vibration and shock.
5.6 Provisions for handling
Transformers shall be provided with suitable means for handling by cranes or similar equipment.
5.7 Temperature of the cooling liquid
The temperature of the cooling liquid may be up to 1 30 °C at the inlet of the transformer.
NOTE Condensation caused by high cooling liquid flow or low cooling liquid temperature in relation to the relative humidity
should be prevented.
6 Test conditions
6.1 General
The tests shall be carried out on new, dry and completely assembled transformers at an ambient air temperature
between 1 10 °C and 1 40 °C. The ventilation shall be identical with that prevailing under normal service
conditions. When placing the measuring devices, the only access permitted shall be through openings with cover
plates, inspection doors or easily removable panels provided by the manufacturer. The measuring devices used
shall not interfere with the normal ventilation of the transformer or cause transfer of heat to or from it.
Liquid cooled transformers shall be tested with liquid conditions as specified by the manufacturer.
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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
The accuracy of measuring instruments shall be:
a) electrical measuring instruments: Class 0,5 (0,5 % full scale, see IEC 60051-2);
b) thermometer: 2 K.
±
Unless otherwise specified, the tests required in this International Standard are type tests.
The sequence for some of the type tests is specified in 6.2.
The routine tests are specified in 6.3.
Compliance with other standards referred to shall be checked according to these standards.
6.2 Type tests
All type tests shall be carried out on the same transformer except otherwise specified.
Those type tests given below shall be carried out in the following sequence without delay between f), g), h) and i).
a) General visual inspection;
b) Insulation resistance (see 7.1) preliminary check;
c) Thermal rating (see clause 8);
d) Rated short-circuit voltage (see clause 10);
e) Protection provided by the enclosure (see 7.3.1);
f) Insulation resistance (see 7.1);
g) Dielectric strength (see 7.2);
h) Dynamic characteristic (see clause 12);
i) General visual inspection.
The other tests of this International Standard not mentioned above may be carried out in any convenient sequence.
NOTE The preliminary check on insulation resistance is required to determine whether the transformer is safe to connect
to the supply.
6.3 Routine tests
Each transformer shall be submitted successively to the following routine tests.
a) General visual inspection;
b) Dielectric strength (see 7.2);
c) Rated no-load output voltage (see clause 9);
d) Cooling liquid circuit (see clause 11);
e) General visual inspection.
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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
7 Protection against electric shock
7.1 Insulation resistance
The insulation resistance shall not be less than 50 MV.
Compliance is checked by measuring the insulation resistance using a d.c. voltage of 500 V between
a) the input and output windings and
b) the windings and the frame.
7.2 Dielectric strength (routine test)
The insulation shall withstand the following test voltages without any flashover or breakdown and no damage shall
occur which might impair the function of the insulation.
Compliance is checked according to IEC 60664-1 and the following test.
An a.c. voltage, having the frequency of the mains supply, of:
a) 4 000 V r.m.s. for integrated gun transformers and
b) 2 500 V r.m.s. for all other transformers
is applied between the inlet and one winding of the outlet circuit, of class I or class II transformers. However, if the
design of class I is so that one point of the secondary is connected to earth, the test voltage can be decreased to
2 500 V r.m.s.
An a.c. voltage of 1 000 V r.m.s. having the same shape is applied between one winding of the outlet circuit and
earth.
The 1 000 V test voltage shall be applied instantaneously.
The 2 500 V and 4 000 V test voltages shall be applied progressively so that the prescribed value is reached in
about 20 s.
In both cases, the test voltage shall be continuously maintained at the required value for 60 s, then stopped as
quickly as the equipment allows, without creating overvoltage during stopping.
NOTE Dielectric tests shall not normally be repeated on a same transformer. If, for any reason, they should be, they should
be tested again with a test voltage of only 75 % of the above-mentioned values.
7.3 Protection against electric shock in normal service (direct contact)
The minimum degree of protection for transformers provided by the enclosure shall be IP 54 as specified in
IEC 60529.
If the transformer is intended to be in-built, the degree of protection may be IP 00.
Compliance is checked according to IEC 60529.
7.4 Protection against electric shock in case of a fault condition (indirect contact)
Transformers shall be built to protection class I or II according to IEC 60536-2.
Compliance is checked by visual inspection.
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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
7.5 Isolation of input and output circuits
The welding circuit shall be electrically isolated from the input circuit and from all other circuits having a voltage
higher than the no-load voltage by reinforced or double insulation. If another circuit is connected to the output
circuit, the power of the other circuit shall be supplied by an isolating transformer or equivalent means.
Compliance is checked by visual inspection of the design.
8 Thermal requirements
8.1 Limits of temperature rise
The thermal requirements for transformers are given as follows:
a) for windings: in accordance with 8.1.1;
b) for accessible surfaces: in accordance with 8.1.2.
8.1.1 Windings
The temperature rise of windings shall not exceed the values given in Table 2.
No part shall be allowed to reach any temperature that will damage another part even though that part might be in
compliance with Table 2.
Table 2 — Temperature limits for windings
Limits of temperature rise
K
Class Peak
of insulation in temperature in
Air cooled windings Liquid cooled windings
accordance with accordance with
IEC 60085 IEC 60905
Embedded Embedded
°C °C temperature Resistance temperature Resistance
sensor sensor
105 (A) 140 60 60 70 70
120 (E) 155 75 75 85 85
130 (B) 165 85 85 95 95
155 (F) 190 110 105 120 115
180 (H) 220 135 130 145 140
200 235 155 145 165 155
220 250 175 160 185 170
NOTE 1 The highest temperature occuring in a winding (hot spot) can be measured by embedded temperature sensors. The
temperature measured by the resistance method gives the average between all temperatures occurring in the windings.
NOTE 2 Other classes of insulation having higher temperature limits than those given in Table 2 are available, see
IEC 60085.
Compliance is checked by measurement in accordance with 8.2.
8.1.2 Accessible surfaces
The temperature rise with reference to the ambient air temperature (see 5.2) and the cooling liquid (see 5.7) for
accessible surfaces shall not exceed the limits given in Table 3.
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SIST EN ISO 5826:2003
© ISO
ISO 5826:1999(E)
Table 3 — Limits of temperature rise for accessible surfaces
Limits of temperature rise
K
Accessible surface
Air cooled transformers Liquid cooled transformers
Bare metal enclosures 25 35
Painted metal enclosures 35 45
Non-metallic enclosures 45 55
Metal handles 10 20
Non-metallic handles 30 40
Compliance is checked by measurement in accordance with 8.2 using a surface temperature sensor (see 8.3.3).
8.2 Heating test
T
...