BS EN 60974-8-2009 Arc welding equipment — nPart 8 Gas consoles for welding and plasma ncutting systems《弧焊设备 第8部分 焊接和等离子切割设备用气体控制台》.pdf

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 1Arc welding equipment Part 8: Gas consoles for welding and plasma cutting systemsBS EN 60974-8:2009National forew

2、ordThis British Standard is the UK implementation of EN 60974-8:2009. It isidentical to IEC 60974-8:2009. It supersedes BS EN 60974-8:2004 which iswithdrawn.The UK participation in its preparation was entrusted to Technical CommitteeWEE/6, Electric arc welding equipment.A list of organizations repre

3、sented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct application. BSI 2009ISBN 978 0 580 58740 5ICS 25.160.30Compliance with a British Standard cannot confer i

4、mmunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 30 September 2009Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 60974-8:2009EUROPEAN STANDARD EN 60974-8 NORME EUROPENNE EUROPIS

5、CHE NORM March 2009 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: avenue Marnix 17, B - 1000 Brussels 2009 CENELEC - All rights of exploitation in any form and by a

6、ny means reserved worldwide for CENELEC members. Ref. No. EN 60974-8:2009 E ICS 25.160 Supersedes EN 60974-8:2004English version Arc welding equipment - Part 8: Gas consoles for welding and plasma cutting systems (IEC 60974-8:2009) Matriel de soudage larc - Partie 8: Consoles de gaz pour soudage et

7、systmes de coupage plasma (CEI 60974-8:2009) Lichtbogenschweieinrichtungen - Teil 8: Gaskonsolen fr Schwei- und Plasmaschneidsysteme (IEC 60974-8:2009) This European Standard was approved by CENELEC on 2009-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which st

8、ipulate 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 Stan

9、dard 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 natio

10、nal 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

11、, Switzerland and the United Kingdom. BS EN 60974-8:2009EN 60974-8:2009 - 2 - Foreword The text of document 26/381/CDV, future edition 2 of IEC 60974-8, prepared by IEC TC 26, Electric welding, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60974-8 on 2009-03-01. Th

12、is European Standard supersedes EN 60974-8:2004. The significant changes with respect to EN 60974-8:2004 are the following: removal of intrinsically safe design; introduction of gas mixing function; new informative rating plate layout; induced changes due to publication of EN 60974-1:2005. This stan

13、dard is to be used in conjunction with EN 60974-1. 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) 2009-12-01 latest date by which the national standards conflicting with the

14、EN have to be withdrawn (dow) 2012-03-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60974-8:2009 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be

15、 added for the standards indicated: IEC 60204-1 NOTE Harmonized as EN 60204-1:2006 (modified). IEC 60664-1 NOTE Harmonized as EN 60664-1:2007 (not modified). IEC 60974-2 NOTE Harmonized as EN 60974-2:2008 (not modified). IEC 60974-3 NOTE Harmonized as EN 60974-3:2007 (not modified). IEC 60974-7 NOTE

16、 Harmonized as EN 60974-7:2005 (not modified). IEC 61010-1 NOTE Harmonized as EN 61010-1:2001 (not modified). _ BS EN 60974-8:2009- 3 - EN 60974-8:2009 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following referenced docu

17、ments are indispensable for the application 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. NOTE When an international publication has been modified by common modificatio

18、ns, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60050-151 -1)International Electrotechnical Vocabulary (IEV) - Part 151: Electrical and magnetic devices - - IEC 60529 -1)Degrees of protection provided by enclosures (IP Code) EN 60529 + corr. May 19912)1993 I

19、EC 60974-1 2005 Arc welding equipment - Part 1: Welding power sources EN 60974-1 2005 1)Undated reference. 2)Valid edition at date of issue. BS EN 60974-8:2009 2 60974-8 IEC:2009 CONTENTS 1 Scope.6 2 Normative references .6 3 Terms and definitions .6 4 Environmental conditions7 5 Tests 7 5.1 Test co

20、nditions7 5.2 Measuring instruments 7 5.3 Conformity of components.7 5.4 Type tests .7 5.5 Routine tests .8 5.5.1 External gas console .8 5.5.2 Internal gas console 8 6 Protection against electric shock 8 6.1 Insulation 8 6.2 Protection against electric shock in normal service (direct contact) .8 6.

21、2.1 Protection provided by the enclosure.8 6.2.2 Capacitors.8 6.3 Protection against electric shock in case of a fault condition (indirect contact) 8 7 Thermal requirements.9 7.1 Heating test.9 7.2 Maximum temperature.9 8 Connections for plasma cutting torches 9 9 Mechanical requirements9 9.1 Protec

22、tion against fire or explosion9 9.2 Gas line purging 9 9.3 Enclosure10 9.3.1 Design requirements10 9.3.2 Enclosure purging10 9.3.3 Safe design of gas console11 9.3.4 Open structure.11 9.3.5 Solid filled enclosure .11 9.4 External gas console .11 9.5 Internal gas console 12 10 Gas lines 12 10.1 Gas h

23、oses and tubing12 10.2 Gas fittings12 10.3 Leak test .12 11 Control circuits .13 12 Rating plate13 12.1 External gas console .13 12.2 Internal gas console 13 13 Instructions and markings.14 13.1 Instructions .14 13.2 Marking .14 BS EN 60974-8:200960974-8 IEC:2009 3 Annex A (informative) Mechanized p

24、lasma system diagram .15 Annex B (informative) Example of a rating plate layout 16 Bibliography17 Figure A.1 Example of a mechanized plasma system.15 Figure B.1 Principle of a rating plate 16 Table 1 Colour coding and marking12 BS EN 60974-8:2009 6 60974-8 IEC:2009 ARC WELDING EQUIPMENT Part 8: Gas

25、consoles for welding and plasma cutting systems 1 Scope This part of IEC 60974 specifies safety and performance requirements for gas consoles intended to be used with combustible gases or oxygen. These gas consoles are designed to supply gases for use in arc welding, plasma cutting, gouging and alli

26、ed processes in non-explosive atmospheres. The gas console can be external or internal to the power source enclosure. In the latter case, this standard also applies to the power source. NOTE See Annex A for mechanised plasma system diagram. 2 Normative references The following referenced documents a

27、re indispensable for the application 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 60050-151, International Electrotechnical Vocabulary Part 151: Electrical and mag

28、netic devices IEC 60529, Degrees of protection provided by enclosures (IP Code) IEC 60974-1:2005, Arc welding equipment Part 1: Welding power sources 3 Terms and definitions For the purposes of this document, the following terms and definitions, as well as those of IEC 60050-151and IEC 60974-1, appl

29、y. 3.1 gas console device for gas-flow routing, mixing or both that contains electrical apparatus in a single or multiple enclosure, or open structure 3.2 lower explosion limit LEL concentration of flammable gas or vapour in air, below which the gas atmosphere is not explosive IEV 426-02-09, modifie

30、d 11 1Figures in square brackets refer to the bibliography. BS EN 60974-8:200960974-8 IEC:2009 7 3.3 lower flammability limit LFL minimum concentration of combustible gas in a mixture where a combustion can be ignited by an ignition source 3.4 upper explosion limit UEL concentration of flammable gas

31、 or vapour in air, above which the gas atmosphere is not explosive IEV 426-02-10, modified 3.5 upper flammability limit UFL maximum concentration of combustible gas in a mixture where a combustion can be ignited by an ignition source 3.6 external gas console gas console not incorporated in a power s

32、ource 3.7 internal gas console gas console incorporated in a power source 3.8 single-fault condition condition in which one means for protection against hazard is defective NOTE If a singe-fault condition results unavoidably in another single-fault condition, the two failures are considered as one s

33、ingle-fault condition. IEC 61010-1, definition 3.5.11, modified 7 4 Environmental conditions As specified in Clause 4 of IEC 60974-1. 5 Tests 5.1 Test conditions As specified in 5.1 of IEC 60974-1. 5.2 Measuring instruments As specified in 5.2 of IEC 60974-1. 5.3 Conformity of components As specifie

34、d in 5.3 of IEC 60974-1. 5.4 Type tests As specified in 5.4 of IEC 60974-1. BS EN 60974-8:2009 8 60974-8 IEC:2009 The other tests included in this standard may be carried out in any convenient sequence. 5.5 Routine tests 5.5.1 External gas console All routine tests shall be carried out on each exter

35、nal gas console in the following sequence: a) general visual inspection, see 3.7 of IEC 60974-1; b) continuity of protective circuit, see 10.4.2 of IEC 60974-1; c) dielectric strength, see 6.1.5 of IEC 60974-1; d) leak test, see 10.3; e) general visual inspection, see 3.7 of IEC 60974-1. 5.5.2 Inter

36、nal gas console All routine tests, as specified in 5.5 of IEC 60974-1, shall be carried out on each internal gas console, with the following addition: g) leak test, see 10.3. 6 Protection against electric shock 6.1 Insulation As specified in 6.1 of IEC 60974-1, with the following exception: Printed

37、circuit boards shall be enclosed, coated, or encapsulated. 6.2 Protection against electric shock in normal service (direct contact) 6.2.1 Protection provided by the enclosure The minimum degree of protection for gas consoles shall be IP21S in accordance with IEC 60529. Conformity shall be checked by

38、 a) applying the articulated finger and ball, as specified in IEC 60529, to any openings and ensuring it does not contact any hazardous parts; and b) verifying that immediately after the water test, as specified in IEC 60529, the unit satisfies insulation resistance and the dielectric strength tests

39、 and is able to operate. No power is applied to the unit while performing these tests. 6.2.2 Capacitors As specified in 6.2.2 of IEC 60974-1. 6.3 Protection against electric shock in case of a fault condition (indirect contact) As specified in 6.3 of IEC 60974-1. BS EN 60974-8:200960974-8 IEC:2009 9

40、 7 Thermal requirements 7.1 Heating test As specified in 7.1 of IEC 60974-1. For an external gas console, only the relevant tests are performed. 7.2 Maximum temperature The temperature at any point shall not exceed the ignition temperature of any combustible gas intended to be used in the gas consol

41、e. Conformity shall be checked by operating the gas console as specified by the manufacturer a) with the combinations of gas(es) and flow rates which creates the worst-case condition, as specified by the manufacturer; b) with the cooling liquid as specified by the manufacturer. 8 Connections for pla

42、sma cutting torches As specified in 11.4.6 of IEC 60974-1, where the torch connects to the gas console. 9 Mechanical requirements As specified in Clause 14 of IEC 60974-1, with the following additions. 9.1 Protection against fire or explosion The gas console shall be designed to prevent fire or expl

43、osion under normal operating conditions and under a single-fault condition (for example, defective valve, hose, etc.). Where a gas console uses a combustible gas, any circuit, subassembly, or component shall not be capable of creating temperatures or a spark with sufficient energy to cause an igniti

44、on. Where a gas console uses a combustible gas in a mixture, the mixture shall not be included within flammability limit that is defined by LFL and UFL. Conformity shall be checked by a) design evaluation and calculations of the circuits, subassembly, or component verification; or b) applying a faul

45、t (for example, open circuit, short circuit, and/or restriction of movement) to the circuits, subassembly, or component until an event occurs (for example, a spark which does not cause ignition, fuse opens, unit shuts down, etc.) or a steady-state temperature is achieved. 9.2 Gas line purging The ga

46、s console shall have a means to purge gas lines when changing to a different type of gas (for example, oxidizing or oxygen containing to combustible) to reduce the risk of fire or explosion. In some cases, a small amount of combustible gas or oxygen may accumulate in the torch. This volume shall be

47、small enough so that no risk can result. The purging shall occur after each change in gas routing or when the previous gas routing is unknown. BS EN 60974-8:2009 10 60974-8 IEC:2009 NOTE 1 A means of accomplishing this can be by purging the lines with a sufficient volume of an inert gas. NOTE 2 When

48、 a risk of fire or explosion exists in the gas lines due to changing gas, the purging can be performed with the following pressure cycle: 1. reduce the pressure of the gas console circuit to atmosphere pressure; 2. purge the gas console circuit with the purging gas; 3. increase the pressure to the m

49、aximum pressure of purging gas; 4. reduce the pressure of the gas console circuit to atmosphere pressure. Conformity shall be checked by risk analysis and the following test. The gas lines, when installed with all devices (valves, fittings, etc.) shall be filled with a combustible gas and measured with a gas detector. Immediately after, the gas lines shall be purged according to the instruction manual. Once purging has been completed, the contents of th