EN 50504:2008

SLOVENSKI STANDARD
01-januar-2009
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SIST ENV 50184:2002
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Validation of arc welding equipment
Validierung von Lichtbogenschweißeinrichtungen
Validation du matériel de soudage à l'arc
Ta slovenski standard je istoveten z: EN 50504:2008
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 50504
NORME EUROPÉENNE
July 2008
EUROPÄISCHE NORM
ICS 25.160.10
English version
Validation of arc welding equipment

Validation du matériel de soudage à l'arc Validierung von
Lichtbogenschweißeinrichtungen

This European Standard was approved by CENELEC on 2008-06-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50504:2008 E
Foreword
This European Standard has been prepared by the Technical Committee CENELEC TC 26A,
Electric arc welding equipment.
The text of the draft was submitted to the formal vote and was approved by CENELEC as
EN 50504 on 2008-06-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2009-06-01

– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2011-06-01

This European Standard has been developed under the authority of CLC/TC 26A, Electric arc
welding equipment. Welding is considered to be a special process because the final result
may not always be capable of being verified by testing, hence it requires continuous control
and/or adherence to documented procedures.
This European Standard has been developed to identify the controls and procedures required.
It requires the use of calibrated welding equipment, then the quality/consistency of the weld
depends upon accurate and repeatable setting of parameters such as current, voltage, speed,
gas flow, etc.
This European Standard concentrates on validating equipment built to the constructional
standard EN 60974-1. The accuracy of this equipment is designated as standard grade.
A higher level of accuracy (precision grade) is introduced in this document.
As a code of practice, this European Standard takes the form of guidance and
recommendations. It should not be quoted as if it were a specification and particular care
should be taken to ensure that claims of compliance are not misleading.
A standard does not purport to include all necessary provisions of a contract. Users of
standards are responsible for their correct application.
Compliance with a standard does not of itself confer immunity from legal obligations.
__________
– 3 – EN 50504:2008
Contents
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Validation accuracies . 7
5 Consistency . 8
6 Frequency of validation and calibration . 8
7 Validators of welding equipment . 8
8 Validation . 8
8.1 General . 8
8.2 Manual metal arc welding with covered electrodes . 9
8.3 Tungsten inert gas . 9
8.4 Metal inert/active gas and flux cored arc welding . 10
8.5 Auxiliary co mponents . 10
9 Validation techniques . 10
9.1 General . 10
9.2 Safety precautions . 10
9.3 Instrumentation. 11
9.4 Power source loads . 12
9.5 Method . 13
10 Validation labels and ce rtifi c ates . 14
10.1 Validation labels . 14
10.2 Validation certificate . 15
Annex A (informative) Accuracies for precision grade power sources . 16
Annex B (informative) Wire feed equipment . 17
B.1 Validation accuraci es . 17
B.2 Requirements for validation . 17
B.3 Method . 18
Annex C (informative) Slope, pulse and synergic controls . 19
C.1 Validation accuracy . 19
C.2 Requirements for validation . 19
C.3 Method . 19
C.4 Pulsed MIG and synergic controls . 20
Annex D (informative) Precautions to be taken with TIG welding equipment . 21
Annex E (informative) Validation of ancillary components in a welding s ystem . 22
Annex F (informative) Voltage drops in the welding circuit . 23
Bibliography . 25
Figure
Figure F.1 . 23
Tables
Table 1 – Validation accuracies for standard grade power sources . 7
Table A.1 – Validation accuracies for precision grade power sources . 16
Table B.1 – Validation accuracies for wire feed equipment . 17
Table F.1 – Voltage drop in copper and aluminium welding cables at normal and elevated
temperatures . 24

Introduction
The quality and consistency of a weld depends on the welder, the materials and the welding
equipment. Variability in the output of the welding equipment will affect the quality of the weld.
In some arc welding processes, e.g. MMA, the welder controls the process through his
experience and measurement of run out length is used to monitor the heat input. However, in
other arc welding processes the quality of the weld depends upon accurate and repeatable
setting of parameters such as current, voltage, speed, gas flow, pulse characteristics, etc.
The relevant construction standard for arc welding equipment is EN 60974-1. This standard
sets the reference level for the accuracy and consistency of the welding output. EN 60974-1
derives its specification for performance accuracy from the requirements of manual welding.
In manual welding the welder plays a key role in adapting and adjusting the output of the
equipment to meet the requirements of the weld. This adaptability allows equipment to be
constructed with a relaxed specification for calibration of output.
Mechanised welding methods lack the skilled adaptability of the manual welder and require
precise control of all aspects of the welding process. The control of the output of the welding
equipment is of particular importance. Manufacturers have responded to this need by
producing equipment with an accuracy of output control and calibration, which exceed the
requirements of EN 60974-1.
In addition to the demands of mechanized welding, manual welding methods have become
more refined and welding procedures often call for the precise control of power source
outputs to limit the freedom of the manual welder in order to produce particular results.
The improvement in equipment construction, the adoption of mechanized welding, the
introduction of quality assurance programmes and the increased understanding of the factors
which control weld quality have led to the demand for more rigorous calibration and validation
of welding equipment performance.
The term calibration has been used in the foregoing text to introduce the general subject of
checking that the welding equipment output meets the manufacturer's specification and is fit
for the purpose of making welds. This is a commonly accepted term for this checking
operation but it does not meet the strict definition of the word calibration.
Clause 3 of this document gives the definition of calibration. The operation of calibration can
be applied only to determining and adjusting the errors of a measuring instrument. An item of
welding equipment is not a measuring instrument though the meters fitted to the welding
equipment are and can be calibrated. The difficulty of terminology and the checking task is
further compounded as many pieces of welding equipment do not have calibrated outputs but
are scaled in arbitrary units. Again this is a function of the manual welding usage in which the
skill of the manual welder is used to adjust and set the welding variables. It is necessary to
use an alternative term to describe the operation of verifying that the welding equipment is fit
for the intended purpose. The term selected is validation.
Validation is the operation which verifies that the welding equipment conforms to the
operating specification for that equipment. If the equipment fails to conform to the
specification then the correction of the errors within the equipment is outside the scope of this
European Standard. That operation is the province of the manufacturers or equipment
specialists.
– 5 – EN 50504:2008
It is implicit in the introduction of a more rigorous standard of accuracy of control of output for
welding equipment that the scope of application of that standard should be defined. This
European Standard defines two levels of accuracy. One is derived directly from EN 60974-1
and is called standard grade. A higher level of accuracy for more exacting welding
applications is defined, called precision grade, and this is given in Annex A for information.
The use of precision grade is dependent upon the welding application.
The welding equipment covered by this European Standard will be fitted with controls
intended to regulate the output of the welding equipment. The controls may be scaled in
absolute units (amperes, volts and metres per minute) or in arbitrary units (numbers, letters,
geometrical marks). Controls scaled in absolute units may b
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