1、September 2007DEUTSCHE NORM English price group 12No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 25.160.10!$IF“138253
2、5www.din.deDDIN EN ISO 17657-3Resistance welding Welding current measurement for resistance welding Part 3: Current sensing coil (ISO 17657-3:2005)English version of DIN EN ISO 17657-3:2007-09Widerstandsschweien Schweistrommessung fr das Widerstandsschweien Teil 3: Strommessspule (ISO 17657-3:2005)E
3、nglische Fassung DIN EN ISO 17657-3:2007-09SupersedesDIN ISO 17657-3:2006-02www.beuth.deDocument comprises 23 pages 11.07DIN EN ISO 17657-3:2007-09 2 National foreword This standard has been prepared by Technical Committee ISO/TC 44 “Welding and allied processes”, Subcommittee SC 6 “Resistance weldi
4、ng” (Secretariat: DIN, Germany) and has been adopted as EN ISO 17657-3:2007 by Technical Committee CEN/TC 121 “Welding”. The responsible German body involved in its preparation was the Normenausschuss Schweitechnik (Welding Standards Committee), Joint Committee NA 092-00-12 AA Widerstandsschweien (D
5、VS AG V 3). DIN EN ISO 17657 consists of the following parts, under the general title Resistance welding Welding current measurement for resistance welding: Part 1: Guidelines for measurement Part 2: Welding current meter with current sensing coil Part 3: Current sensing coil Part 4: Calibration sys
6、tem Part 5: Verification of welding current measuring system The DIN Standard corresponding to the International Standard referred to in the EN is as follows: ISO 669 DIN ISO 669 Amendments This standard differs from DIN ISO 17657-3:2006-02 as follows: a) The text of ISO 17657-3 has been adopted by
7、CEN without any modification. Previous editions DIN ISO 17657-3: 2006-02 National Annex NA (informative) Bibliography DIN ISO 669, Resistance welding Resistance welding equipment Mechanical and electrical requirements EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 17657-3 June 2007 ICS 25.
8、160.10 English Version Resistance welding - Welding current measurement for resistance welding - Part 3: Current sensing coil (ISO 17657-3:2005) Soudage par rsistance - Mesurage des courants en soudage par rsistance - Partie 3: Tore de mesure de courant (ISO 17657-3:2005) Widerstandsschweien - Schwe
9、istrommessung fr das Widerstandsschweien - Teil 3: Strommessspule (ISO 17657-3:2005) This European Standard was approved by CEN on 19 May 2007. 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 n
10、ational standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version
11、in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmar
12、k, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATI
13、ON EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 17657-3:2007: EContents Page 2 EN ISO 17657-3:2007 (E)Foreword .3 Introduction 4 1 Sc
14、ope5 2 Normative references .5 3 Terms and definitions .5 4 Physical environment and operating conditions 6 5 Classification of current sensing coils and designation of product 6 5.1 Class of current sensing coils .6 5.2 Standard values of the conversion coefficient 6 5.3 Designation of products .7
15、6 Requirements for current sensing coils .7 6.1 Current sensing coil and connecting lead .7 6.2 Conversion coefficient .7 6.3 Measuring accuracy .8 6.4 Mechanical strength .8 6.5 Setting position error .8 6.6 Influence of ambient temperature 8 6.7 Thermal property of cover materials 8 6.8 Test .8 7
16、Test procedures 9 7.1 Conversion coefficient .9 7.2 Measuring accuracy .10 7.3 Mechanical tests .10 7.4 Setting position error test 12 7.5 Thermal test .12 7.6 Contact test .12 8 Marking 12 Annex A (informative) Design of current sensing coils .13 Annex B (informative) Governing parameters of the co
17、nversion coefficient 16 Annex C (informative) Type of current sensing coils and their recommended specification range .17 Annex D (informative) Frequency response of current sensing coils 21 Foreword The text of ISO 17657-3:2005 has been prepared by Technical Committee ISO/TC 44 “Welding and allied
18、processes” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 17657-3:2007 by Technical Committee CEN/TC 121 “Welding”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication o
19、f an identical text or by endorsement, at the latest by December 2007, and conflicting national standards shall be withdrawn at the latest by December 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this
20、European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United
21、 Kingdom. Endorsement notice The text of ISO 17657-3:2005 has been approved by CEN as EN ISO 17657-3:2007 without any modifications. 3 EN ISO 17657-3:2007 (E)Introduction Requests for official interpretations of any aspect of this part of ISO 17657 should be directed to the Secretariat of ISO/TC 44/
22、SC 6 via your national standards body. A complete listing of these bodies can be found at http:/www.iso.org. 4 EN ISO 17657-3:2007 (E)1 Scope This part of ISO 17657 specifies current sensing coils of the toroidal-coil type as a current sensor for welding current meters or a welding current measuring
23、 system used to monitor the welding current in resistance welding, and is applicable for both current types, i.e. alternating current of 50 Hz or 60 Hz and direct current. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated refe
24、rences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 669, Resistance welding Resistance welding equipment Mechanical and electrical requirements ISO 17657-4, Resistance welding Welding current measuremen
25、t for resistance welding Part 4: Calibration system 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 669 and the following apply. 3.1 current sensing coil (toroidal coil) multi-wound coil, in which wire is wound around a non-magnetic core of constant
26、cross-section, used for detecting the magnetic flux generated by current NOTE The coil is mounted around or encircles a conductor through which the current to be measured passes. 3.2 reference current sensing coil current sensing coil calibrated at a higher accuracy than the highly accurate class de
27、fined in this part of ISO 17657 3.3 conversion coefficient ratio of output voltage from a current sensing coil against the welding current, expressed in millivolts per kiloamp (mV/kA) NOTE The value is proportional to the frequency of the measured current, and is defined with a perfectly full-wave c
28、urrent of 50 Hz as the test current. 5 EN ISO 17657-3:2007 (E)3.4 frequency response feature indicating the influence of frequency of test current on the conversion coefficient 3.5 accuracy scatter and deviation of the conversion coefficient NOTE The output load of the current sensing coil strongly
29、influences the value of the conversion coefficient. If the output load and/or input impedance of an integrator changes, the conversion coefficient may deviate even though both devices have been separately calibrated in a highly accurate class. 4 Physical environment and operating conditions Unless o
30、therwise specified, the current sensing coil shall be capable of operating under the following conditions: at an ambient air temperature between +5 C and +40 C; in relative humidity up to 95 %; at altitudes up to 1 000 m above mean sea level; where gas, fine dust, oil mist, spatters, etc. are includ
31、ed in the air such as those caused by ordinary arc or spot welding work. When the operating conditions are not of any of those specified above, an agreement may be needed between the manufacturer and the purchaser. 5 Classification of current sensing coils and designation of product 5.1 Class of cur
32、rent sensing coils The current sensing coils shall be classified depending on construction, conversion coefficient and measuring accuracy. Classifications by the accuracy are shown in Table 1. Table 1 Classification of current sensing coils Classification Measuring accuracy Application Highly accura
33、te class 0,5 % of full scale Laboratory use Accurate class 1,0 % of full scale Routine use for highly accurate systems Ordinary class 3,0 % of full scale Routine use for ordinary systems 5.2 Standard values of the conversion coefficient Rated values of the standard conversion coefficient, K, shall b
34、e of 150 mV/kA, 220 mV/kA and 1,5 V/kA for full-wave alternating current of 50 Hz. NOTE If a different test frequency is used for defining the conversion coefficient, the value can be converted by using equation (1) described in 7.1. 6 EN ISO 17657-3:2007 (E)5.3 Designation of products The following
35、 shall be indicated: design type as designated by type of construction; conversion coefficient; specified accuracy class; coil size (length for flexible type, and inner diameter for rigid type). The designation of length can be omitted if the value is not needed. EXAMPLE 1 Flexible type of 800 mm le
36、ngth, conversion coefficient of 150 mV/kA at 50 Hz, and accurate class. Flexible (800 mm) 150 mV/kA, 50 Hz, class 1.0 EXAMPLE 2 Rigid type of 200 mm inner diameter, conversion coefficient of 180 mV/kA at 60 Hz, and highly accurate class. Rigid (200 mm) 180 mV/kA, 60 Hz, class 0.5 6 Requirements for
37、current sensing coils 6.1 Current sensing coil and connecting lead The current sensing coil, connector and connecting lead from the coil to the integrator/amplifier shall be designed such that the coil is sensitive only to magnetic flux generated by current flow through the conductor within the coil
38、. Any external magnetic flux across the coil is not measured. The output of the coil is proportional to a derivative of the measured current waveform. If a flexible or rigid hatched-type coil is used, both ends of the sensing coil shall be fixed leaving little or no space between the ends. To avoid
39、wave distortion, the connecting lead and connector should be protected from magnetic flux and should have low inductance. A low inductive resistance shall be connected to the ends of the connecting lead as the output load, RL. The value should be constant between 200 and 1 k. 6.2 Conversion coeffici
40、ent The rated conversion coefficient of current sensing coils should conform with those described in 5.2. The values shall be checked, and adjusted according to the method described in 7.1 using full-wave currents. The scatter of the conversion coefficient shall be checked using a reference current
41、meter and data acquisition system, or a reference current sensing coil and a data acquisition system. The correction shall be performed by inserting a small resistance, ra, in the end of coil or the end of connection lead as shown in Figure A.1. The coefficient value should not be adjusted by contro
42、lling the value of the output load RL. If the coils are checked with an alternating current of 60 Hz, the value shall be divided by 1,2 (= 60/50) to get the conversion coefficient in 50 Hz. The input impedance of an integrator, connected to the current sensing coil, influences the value of conversio
43、n coefficient. The output voltage should be measured with a high-input impedance device larger than 500 k as for the data acquisition system, with the output load specified in 6.1 connected if the coil does not include a resistor. The conversion coefficient values for an alternating current of 60 Hz
44、 can be checked and adjusted although the value is indicated in 50 Hz. In the case of an alternating current of 60 Hz, the conversion coefficient marked on the coil is calculated according to Equation (1) described in 7.1. 7 EN ISO 17657-3:2007 (E)6.3 Measuring accuracy The measuring accuracy of cur
45、rent sensing coils shall be one shown in Table 1, and shall be checked according to the method described in 7.2 using full-wave alternating currents of 50 Hz or 60 Hz. NOTE Current sensing coils with a small deviation of less than 1 % can be manufactured, which meet the repeat bending requirements a
46、fter 1 000 re-attachments, provided the current conductor is located at positions B, F or H, or near the position illustrated in Figure 1. 6.4 Mechanical strength Mechanical tests shall be applied only to flexible coils. After using mechanical tests according to the methods described in 7.3.2 to 7.3
47、.6 with full-wave alternating currents at 50 Hz or 60 Hz, the measuring accuracy of the tested coil shall comply with those shown in Table 1. 6.5 Setting position error Scatters of the conversion coefficient for the test coil shall be checked according to the method described in 7.4 using full-wave
48、alternating currents of 50 Hz or 60 Hz. The scatters and/or deviation shall be within the measuring accuracy stipulated in Table 1. 6.6 Influence of ambient temperature The influence of ambient temperature on the current sensing coil shall be evaluated according to the method described in 7.5. The s
49、catters and/or deviations of conversion coefficient shall be measured according to the method described in 7.2, and the values shall be within the measuring accuracy shown in Table 1. 6.7 Thermal property of cover materials The cover of current sensing coils shall not be damaged by coming into contact with a wire heated to a temperature of 60 C. If the current sensing coil is mounted within a transformer, the coil shall withstand temperatures according to the insulation class of the transformer. 6.8 Test 6.8.1
