1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Validation of arcwelding equipmentBS EN 50504:2008NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRI
2、GHT LANational forewordThis British Standard is the UK implementation of EN 50504:2008. Thisstandard supersedes BS 7570:2000 which is withdrawn. It is technicallyidentical to BS 7570:2000The UK participation in its preparation was entrusted to TechnicalCommittee WEE/6, Electric arc welding equipment
3、A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application. BSI 2008ISBN 978 0 580 58174 8ICS 25.160.30Compliance with a Bri
4、tish Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 50504:200831 January 2009. EUROPEAN STANDARD EN 5050
5、4 NORME EUROPENNE EUROPISCHE NORM July 2008 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploit
6、ation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50504:2008 E ICS 25.160.10 English version Validation of arc welding equipment Validation du matriel de soudage larc Validierung von Lichtbogenschweieinrichtungen This European Standard was approved by CENELEC on
7、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
8、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 t
9、he 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, Luxemb
10、ourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 50504:2008EN 50504:2008 2 Foreword This European Standard has been prepared by the Technical Committee CENELEC TC 26A, Electric arc welding equipment. The tex
11、t 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 b
12、y 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 o
13、f 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 depen
14、ds 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 accurac
15、y (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 standa
16、rd 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. _ BS EN 50504:2008 3 EN 50504:2008 Contents Introduction . 4 1 Scope 6 2 Norm
17、ative 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 in
18、ert/active gas and flux cored arc welding . 10 8.5 Auxiliary components 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 certificates . 14 10.1 Validation labels . 14 10.2 Validation ce
19、rtificate . 15 Annex A (informative) Accuracies for precision grade power sources . 16 Annex B (informative) Wire feed equipment 17 B.1 Validation accuracies 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
20、 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 system . 22 Annex F (informative) Voltage drops in the weld
21、ing 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 a
22、luminium welding cables at normal and elevated temperatures . 24 BS EN 50504:2008EN 50504:2008 4 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.
23、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 curr
24、ent, 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
25、 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 m
26、ethods 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 con
27、trol 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
28、 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 o
29、f 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 manufacturers specification and is fit for the purpose of making welds. This is a commonly accepted term for this checkin
30、g 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 mea
31、suring 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 t
32、he 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 i
33、s 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 pr
34、ovince of the manufacturers or equipment specialists. BS EN 50504:2008 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 define
35、s 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
36、 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)
37、. Controls scaled in absolute units may be validated and the consistency of those controls scaled in arbitrary units may be assessed. The welding equipment may be fitted with meters that measure the output of the equipment and these meters should normally be validated against the appropriate standar
38、d, unless a different method is used to control the welding process. The use of meters and measuring instrument packages with welding equipment that is required to produce welds of integrity and reliability is strongly recommended. This code of practice recommends the use of resistive loads to valid
39、ate the power source and associated meters. Alternatively, independent instrumentation may be used to monitor the welding process, rather than validating the power source itself. The method of control and type of instrumentation should be detailed on the welding procedure sheet. BS EN 50504:2008EN 5
40、0504:2008 6 1 Scope This European Standard specifies validation methods for arc welding equipment constructed and used to the accuracy specified in EN 60974-1 or other equivalent standards. The accuracy of this equipment is designated as standard grade. This European Standard is applicable to a) arc
41、 welding power sources, b) wire feeders, c) welding instrumentation. This European Standard is not applicable to arc striking and stabilizing device. Calibration, verification and validation of equipment for other welding processes and ancillary equipment which may affect the quality of the weld, e.
42、g. flow gauges, thermocouples, robots and manipulators are given in EN ISO 17662. 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
43、referenced document (including any amendments) applies. EN 60051-1:1998, Direct acting indicating analogue electrical measuring instruments and their accessories Part 1: Definitions and general requirements common to all parts (IEC 60051-1:1997) EN 60974-1, Arc welding equipment Part 1: Welding powe
44、r sources (IEC 60974-1) EN ISO 17662, Welding Calibration, verification and validation of equipment used for welding, including ancillary activities (ISO 17662) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 60974-1 and the following apply. 3.1 calib
45、ration operations for the purpose of determining the magnitude of the errors of a measuring instrument and if necessary to determine other metrological properties 3.2 validation operations for the purpose of demonstrating that an item of welding equipment or a welding system conforms to the operatin
46、g specification for that welding equipment or system 3.3 accuracy closeness of an observed quantity to the defined or true value BS EN 50504:2008 7 EN 50504:2008 3.4 consistency test test to determine the repeatability of the equipment output over a period of time NOTE The results obtained from the
47、present validation are compared to the results of the initial tests. The repeatability/consistency is the difference between these readings. 3.5 class designation according to the accuracy of a measuring instrument conforming to EN 60051-1 NOTE For example class 2,5 refers to 2,5 % full scale deflec
48、tion. 3.6 portable welding monitor (brief case monitor) assembly of measuring instruments packaged in a portable case used to measure, record and/or analyse the welding equipment output 3.7 standard grade grade of validating equipment built to the constructional standard EN 60974-1 3.8 precision gra
49、de grade of validating equipment built to the constructional standard EN 60974-1 but with a higher level of accuracy for more exacting welding applications NOTE See Annex A for power sources and Annex B for wire feeders. 4 Validation accuracies When tested in accordance with Clause 9, the validation accuracies for standard grade power source controls and instrumentation should conform to Table 1. Table 1 Validation accuracies for standard grade power sources Quantity AccuracyCurrent and voltage 10 % of the
