1、BSI Standards PublicationFerrite cores Guidelines on the limits of surface irregularitiesPart 1: General specificationBS EN 60424-1:2016National forewordThis British Standard is the UK implementation of EN 60424-1:2016. It isidentical to IEC 60424-1:2015. It supersedes BS EN 60424-1:2000 which iswit
2、hdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/51, Transformers, inductors, magnetic components and ferrite materials.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include
3、all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 82411 1ICS 29.030; 29.100.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This
4、British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60424-1:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60424-1 March 2016 ICS 29.100.10 Su
5、persedes EN 60424-1:1999 English Version Ferrite cores - Guidelines on the limits of surface irregularities - Part 1: General specification (IEC 60424-1:2015) Noyaux ferrites - Lignes directrices relatives aux limites des irrgularits de surface - Partie 1: Spcification gnrale (IEC 60424-1:2015) Ferr
6、itkerne - Leitfaden fr Grenzwerte von sichtbaren Beschdigungen der Kernoberflche - Teil 1: Fachgrundspezifikation (IEC 60424-1:2015) This European Standard was approved by CENELEC on 2016-01-08. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditi
7、ons 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 CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exis
8、ts 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 CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the nati
9、onal electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Por
10、tugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1
11、000 Brussels 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 60424-1:2016 E BS EN 60424-1:2016EN 60424-1:2016 2 European foreword The text of document 51/1107/FDIS, future edition 2 of IEC 60424-1, prepared by IEC/TC 51 “Magnet
12、ic components and ferrite materials“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60424-1:2016. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement
13、(dop) 2016-10-08 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2019-01-08 This document supersedes EN 60424-1:1999. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and
14、/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60424-1:2015 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have
15、 to be added for the standards indicated: IEC 60401-3 NOTE Harmonized as EN 60401-3. IEC 60424-2 NOTE Harmonized as EN 60424-2. IEC 60424-3 NOTE Harmonized as EN 60424-3. IEC 60424-4 NOTE Harmonized as EN 60424-4. IEC 60424-8 NOTE Harmonized as EN 60424-8. BS EN 60424-1:2016 2 IEC 60424-1:2015 IEC 2
16、015 CONTENTS FOREWORD . 3 INTRODUCTION . 5 1 Scope 6 2 Normative reference 6 3 Terms and definitions. 6 4 Examples of irregularities . 7 5 Locations and functions of core parts and surfaces 7 5.1 General . 7 5.2 Mating surfaces . 7 5.3 Centre post . 8 5.4 Outer walls or legs 8 5.5 Back wall, bottom
17、and back surfaces . 8 5.6 Wire-slot area . 8 5.7 Wire-way area . 8 5.8 Clamping recess area . 8 6 Area and length reference for visual inspection 8 7 Limits of surface irregularities 11 7.1 General . 11 7.2 Chips and ragged edges 11 7.3 Cracks 11 7.4 Flash. 11 7.5 Pull-outs . 11 7.6 Pores 11 7.7 Cry
18、stallites 11 8 Sectional specifications 11 Bibliography 13 Figure 1 Examples of surface irregularities . 7 Figure 2 Location of main core parts and surfaces Example of RM-core type . 7 Table 1 Area and length reference for visual inspection 10 Table 2 IEC 60424 sectional specifications . 12 BS EN 60
19、424-1:2016IEC 60424-1:2015 IEC 2015 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ FERRITE CORES GUIDELINES ON THE LIMITS OF SURFACE IRREGULARITIES Part 1: General specification FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
20、all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards,
21、Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory
22、 work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations
23、. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recom
24、mendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by an
25、y end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional pub
26、lication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by indep
27、endent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any
28、personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative
29、 references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsibl
30、e for identifying any or all such patent rights. International Standard IEC 60424-1 has been prepared IEC technical committee 51: Magnetic components and ferrite materials. This second edition cancels and replaces the first edition published in 1999. This edition constitutes a technical revision. Th
31、is edition includes the following significant technical changes with respect to the previous edition: a) addition of pores in 3.5 and crystallites in 3.6. BS EN 60424-1:2016 4 IEC 60424-1:2015 IEC 2015 The text of this standard is based on the following documents: FDIS Report on voting 51/1107/FDIS
32、51/1123/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 60424 series, published under the genera
33、l title Ferrite cores Guidelines on the limits of surface irregularities, can be found on the IEC website. Future standards in this series will carry the new general title as cited above. Titles of existing standards in this series will be updated at the time of the next edition. The committee has d
34、ecided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amen
35、ded. BS EN 60424-1:2016IEC 60424-1:2015 IEC 2015 5 INTRODUCTION Due to the method of manufacture and the physical nature of the products, ferrite cores can be expected to exhibit some degree of physical irregularities such as chips, ragged edges, cracks, flashing, and pull-out. The permissible exten
36、t of these surface irregularities will depend on the type, position and size of the defect and on the function of the core. Thus, in order to establish limits of surface irregularities for a given series of ferrite cores, for example RM-cores, pot-cores, E-cores, U-cores and ring-cores, it is necess
37、ary to prepare a particular specification for each, setting out in detail the permissible extent of the various types of irregularities. All surfaces of the core should be clean and free from loose ferrite particles or any other foreign matter. This is more critical for mating surfaces that should m
38、ake good contact with one another. Stains, discolorations, surface crazing or crystallization are acceptable if they do not affect the normal performance of the core. The irregularities described below are considered as being detectable without the use of any magnifying equipment. Surface irregulari
39、ties limits are set for control of cosmetic appearance, and not for control of magnetic performance. Surface irregularities do not substantially affect core magnetic function, nor do they affect reliability. Reliability should be assessed for wound magnetics, rather than for cores alone. See IEC 604
40、01-3 for more details concerning the reliability of ferrite cores and devices built with them. BS EN 60424-1:2016 6 IEC 60424-1:2015 IEC 2015 FERRITE CORES GUIDELINES ON THE LIMITS OF SURFACE IRREGULARITIES Part 1: General specification 1 Scope This part of IEC 60424 gives guidelines on the allowabl
41、e limits of surface irregularities of ferrite cores. This standard should be considered as a general specification useful in the dialogue between ferrite core manufacturers and customers about surface irregularities. 2 Normative reference The following documents, in whole or in part, are normatively
42、 referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Void. 3 Terms and definitions For the purposes of this document, the
43、 following terms and definitions apply. 3.1 chips and ragged edges areas with missing surface material that are generally caused by mechanical impact during handling 3.2 crack surface irregularity which has a width much smaller than its length, and penetrates into the core 3.3 flash sharp feather-ed
44、ge wall extending beyond the intended contour surface of the core 3.4 pull-out consequence of the removal of a surface layer of the core due to die “sticking” 3.5 pores holes left on the surface of cores after sintering and surface finishing 3.6 crystallites grains of abnormal size distinguishable o
45、n the surface, often with sparkling facets BS EN 60424-1:2016IEC 60424-1:2015 IEC 2015 7 4 Examples of irregularities Figure 1 shows different examples of surface irregularities on an RM-core. Figure 1 Examples of surface irregularities 5 Locations and functions of core parts and surfaces 5.1 Genera
46、l Figure 2 shows the location of main core parts and surfaces on an RM-core. Figure 2 Location of main core parts and surfaces Example of RM-core type 5.2 Mating surfaces These surfaces are generally ground in order to limit the residual air gap between the two core halves. Consequently, irregularit
47、ies on these surfaces have to be considered as major ones, and carefully evaluated with regard to their influence on the magnetic properties of the complete circuit. IEC Mating surfaces (see 5.2) Centre post (see 5.3) Wire-slot area (see 5.6) Outer walls and legs (see 5.4) Bottom surface (see 5.5) W
48、ire-way area (see 5.7) Back wall (see 5.5) Back surface (see 5.5) Clamping recess area (see 5.8) IEC Pull-out Example of flash Chips Ragged edges Cracks BS EN 60424-1:2016 8 IEC 60424-1:2015 IEC 2015 5.3 Centre post This should be considered as the most important part of the core due to its function
49、 of carrying the total flux generated by the winding. The centre post of ferrite cores is generally circular (with or without a hole) or rectangular. 5.4 Outer walls or legs The main function of the outer walls (for example pot-cores) or the outer legs (for example E-cores) is to guide the magnetic flux in a closed magnetic circuit. 5.5 Back wall, bottom and back surfaces The back wall has the same magnetic function as the outer walls or legs; it may include wire-slots and
