1、BSI Standards PublicationFerrite cores Guidelines on the limits of surface irregularitiesPart 2: RM-coresBS EN 60424-2:2016National forewordThis British Standard is the UK implementation of EN 60424-2:2016. It is identical to IEC 60424-2:2015. It supersedes BS EN 60424-2:1998 which is withdrawn.The
2、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 all the nec
3、essary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 82412 8ICS 29.100.10; 29.030Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Sta
4、ndard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60424-2:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60424-2 March 2016 ICS 29.100.10 Supersedes EN
5、 60424-2:1997 English Version Ferrite cores - Guidelines on the limits of surface irregularities - Part 2: RM-cores (IEC 60424-2:2015) Noyaux ferrites - Lignes directrices relatives aux limites des irrgularits de surface - Partie 2: Noyaux RM (IEC 60424-2:2015) Ferritkerne - Leitfaden fr Grenzwerte
6、von sichtbaren Beschdigungen der Kernoberflche - Teil 2: RM-Kerne (IEC 60424-2:2015) 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 conditions for giving this European Standard the status
7、 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 exists in three official versions (English, French,
8、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 national electrotechnical committees of Austria, Bel
9、gium, 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, Portugal, Romania, Slovakia, Slovenia, Spain, Swede
10、n, 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-1000 Brussels 2016 CENELEC All rights of exploita
11、tion in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 60424-2:2016 E BS EN 60424-2:2016EN 60424-2:2016 2 European foreword The text of document 51/1108/FDIS, future edition 2 of IEC 60424-2, prepared by IEC/TC 51 “Magnetic components and ferrite materials“ was submitt
12、ed to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60424-2:2016. 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 (dop) 2016-10-08 latest date by which the nation
13、al standards conflicting with the document have to be withdrawn (dow) 2019-01-08 This document supersedes EN 60424-2:1997. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identi
14、fying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60424-2:2015 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60
15、424-1 NOTE Harmonized as EN 60424-1. 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 60424-5 NOTE Harmonized as EN 60424-5. BS EN 60424-2:2016 2 IEC 60424-2:2015 IEC 2015 CONTENTS FOREWORD . 3 1 Scope 5 2 Normative
16、references . 5 3 Limits of surface irregularities 5 3.1 Visual inspection and recommended limits . 5 3.2 Chips and ragged edges 6 3.2.1 Chips and ragged edges on mating surfaces 6 3.2.2 Chips and ragged edges on other surfaces . 6 3.3 Cracks 9 3.4 Flash. 10 3.5 Pull-outs . 10 3.6 Crystallites 11 3.7
17、 Pores 12 Bibliography 13 Figure 1 Chips and ragged edges on mating surfaces . 6 Figure 2 Cracks location Top view . 9 Figure 3 Cracks location Bottom view 9 Figure 4 Dimension W 10 Figure 5 Flash and pull-out location 11 Figure 6 Pull-out in clamping recess area . 11 Figure 7 Crystallites location
18、for RM-core . 11 Figure 8 Pores location for RM-core . 12 Table 1 Relevant subclauses for given irregularity versus location 5 Table 2 Allowable chipping areas 6 Table 3 Area and length references for visual inspection . 8 Table 4 Limits for cracks 10 Table 5 W dimensions 10 BS EN 60424-2:2016IEC 60
19、424-2:2015 IEC 2015 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ FERRITE CORES GUIDELINES ON THE LIMITS OF SURFACE IRREGULARITIES Part 2: RM-cores FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical
20、 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, Technical Specifications, Tec
21、hnical 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 work. International, governm
22、ental 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. 2) The formal decisions or
23、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 recommendations for international
24、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 any end user. 4) In order to pr
25、omote 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 publication shall be clearly ind
26、icated 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 independent certification bodies.
27、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 personal injury, property dam
28、age 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 references cited in this pub
29、lication. 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 responsible for identifying any or all
30、such patent rights. International Standard IEC 60424-2 has been prepared by technical committee 51: Magnetic components and ferrite materials. This second edition cancels and replaces the first edition published in 1997. This edition constitutes a technical revision. This edition includes the follow
31、ing significant technical changes with respect to the previous edition: a) addition of crystallites in 3.6 and of pores in 3.7. BS EN 60424-2:2016 4 IEC 60424-2:2015 IEC 2015 The text of this standard is based on the following documents: FDIS Report on voting 51/1108/FDIS 51/1122/RVD Full informatio
32、n 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 general title Ferrite cores Guide
33、lines 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 decided that the contents of
34、 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 amended. BS EN 60424-2:2016IEC
35、60424-2:2015 IEC 2015 5 FERRITE CORES GUIDELINES ON THE LIMITS OF SURFACE IRREGULARITIES Part 2: RM-cores 1 Scope This part of IEC 60424 provides guidelines on the allowable limits of surface irregularities applicable to RM-cores in accordance with the relevant generic specification. This standard s
36、hould be considered as a sectional specification useful in the negotiations between ferrite core manufacturers and customers about surface irregularities. Normative reference 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indi
37、spensable 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. 3 Limits of surface irregularities 3.1 Visual inspection and recommended limits To facilitate quick identific
38、ation of recommended limits for a given irregularity based on its location, the following subclauses are summarized in Table 1. Table 1 Relevant subclauses for given irregularity versus location Location Type of irregularity For limits, see Mating surfaces Chips Ragged edges Cracks 3.2.1 3.2.1 3.3 C
39、entre-post Chips Ragged edges Cracks 3.2.2 3.2.2 3.3 Outer walls Chips Cracks 3.2.2 3.3 Back wall Chips Ragged edges Cracks Pull-outs 3.2.2 3.2.2 3.3 3.5 Wire slot areas Chips Ragged edges Flash 3.2.2 3.2.2 3.4 Wire way areas Chips Ragged edges Flash 3.2.2 3.2.2 3.4 Clamping recess areas Chips Ragge
40、d edges Pull-outs 3.2.2 3.2.2 3.5 BS EN 60424-2:2016 6 IEC 60424-2:2015 IEC 2015 3.2 Chips and ragged edges 3.2.1 Chips and ragged edges on mating surfaces The areas of the chips located on the mating surfaces (C1, C1 and C1 irregularities in Figure 1) shall not exceed the following limits: the cumu
41、lative area of the chips shall be less than 4 % of the total mating surface; the total length of the ragged edges shall be less than 25 % of the perimeter of the relevant surface. Key C1, C1, C1: chip R1, R1: ragged edge L1, L2: length of ragged edge Figure 1 Chips and ragged edges on mating surface
42、s Allowable chipping areas for a given core are summarized in Table 2 Table 2 Allowable chipping areas Core size Mating surfaces (mm2) Other surfaces (mm2) RM4/RM5 2 4 RM6/RM7 3 6 RM8 4,5 9 RM10 7 15 RM12 12,5 25 RM14 15 30 NOTE These limits are applicable to cores with and without a hole in the cen
43、tre-post. 3.2.2 Chips and ragged edges on other surfaces The areas of the chips located on the other surfaces shall not exceed the following limits: The allowable chipping areas are doubled as compared to the limits for the mating surface (see Table 2). The rule for the ragged edges is the same as f
44、or the mating surface. Chips and ragged edges are not acceptable on the ridge of the clamping recess area. IEC Inner edge of wire slot area C1 R1 L1L2R1 C1 C1 BS EN 60424-2:2016IEC 60424-2:2015 IEC 2015 7 Chips and ragged edges are not acceptable on the inner edges of the wire slot area (see Figure
45、1). The area and length references for visual inspection are given in Table 3. BS EN 60424-2:2016 8 IEC 60424-2:2015 IEC 2015 Table 3 Area and length references for visual inspection IEC BS EN 60424-2:2016IEC 60424-2:2015 IEC 2015 9 3.3 Cracks A single continuous crack which intersects the perimeter
46、 of the relevant surface at two points is not acceptable (see S1, S1 and S1 irregularities in Figure 2). The limits for cracks at various locations shown in Figure 2 and Figure 3 are given in Table 4. Figure 2 Cracks location Top view NOTE The boundary between the outer wall and the back wall is sho
47、wn by a dashed line in Figure 3. Figure 3 Cracks location Bottom view IEC S8 S6 S6 S6 Back wall Outer wall IEC S1 S3 S7 S4 S5 S3 S4 S2 S2 S1 S7 S1 BS EN 60424-2:2016 10 IEC 60424-2:2015 IEC 2015 Table 4 Limits for cracks Type Location Limits for single crack Limits for multiple cracks S1, S1, S1 Any
48、 place Not acceptable Not acceptable S2, S2 Mating surface of centre-post 50 % of centre-post thickness Centre-post thickness S3, S3 Mating surface of outer wall Wall thickness, W 2W S4, S4 Centre-post Centre-post thickness Centre-post thickness S5 Outer wall Wall thickness, W 4W S6, S6, S6 Back sur
49、face Back wall thickness 4 back wall thickness S7, S7 Corner of centre-post/back wall and outer wall/back wall 25 % of centre-post circumference 25 % of relevant arc 25 % of centre-post circumference 25 % of relevant arc S8 Side of back wall Lamination cracks in the back wall are not acceptable NOTE For cores without a hole in the centre-post, the centre-post thickness is replaced by a half
