1、BSI Standards PublicationFerrite cores Guidelines on the limits of surface irregularitiesPart 8: PQ-coresBS EN 60424-8:2015National forewordThis British Standard is the UK implementation of EN 60424-8:2015.It is identical to IEC 60424-8:2015.The UK participation in its preparation was entrusted to T
2、echnicalCommittee 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 necessary provisions ofa contract. Users are responsible
3、for its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 84734 9ICS 29.100.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy
4、 and Strategy Committee on 31 December 2015.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60424-8:2015EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60424-8 December 2015 ICS 29.100.10 English Version Ferrite cores - Guidelines on the limits of surface i
5、rregularities - Part 8: PQ-cores (IEC 60424-8:2015) Noyaux ferrites - Lignes directrices relatives aux limites des irrgularits de surface - Partie 8: Noyaux PQ (IEC 60424-8:2015) Ferritkerne - Leitfaden fr Grenzwerte von sichtbaren Beschdigungen der Kernoberflche - Teil 8: PQ-Kerne (IEC 60424-8:2015
6、) This European Standard was approved by CENELEC on 2015-09-09. 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 bibliographica
7、l 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, German). A version in any other language made by translation under the responsibili
8、ty 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, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, For
9、mer Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechni
10、cal Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No.
11、EN 60424-8:2015 E BS EN 60424-8:2015EN 60424-8:2015 2 European foreword The text of document 51/1078/CDV, future edition 1 of IEC 60424-8, prepared by IEC/TC 51 “Magnetic components and ferrite materials“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60424-8:2015. The
12、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) 2016-06-09 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2018-09-09 Att
13、ention 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 identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 60424-8:2015 was approved b
14、y 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 60401-2 NOTE Harmonized as EN 60401-2. IEC 62317-13 NOTE Harmonized as EN 62317-13. BS EN 60424-8:2015EN 60424-8:2015 3 Annex ZA
15、 (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. Fo
16、r undated references, the latest edition of the referenced document (including any amendments) applies. NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. NOTE 2 Up-to-date information on the latest versions of the Euro
17、pean Standards listed in this annex is available here: www.cenelec.eu. Publication Year Title EN/HD Year IEC 60401-1 - Terms and nomenclature for cores made of magnetically soft ferrites - Part 1: Terms used for physical irregularities EN 60401-1 - IEC 60424-1 - Ferrite cores - Guide on the limits o
18、f surface irregularities - Part 1: General specification EN 60424-1 - BS EN 60424-8:2015 2 IEC 60424-8:2015 IEC 2015 CONTENTS FOREWORD . 3 1 Scope 5 2 Normative references 5 3 Terms and definitions 5 4 Limits of surface irregularities 6 4.1 Chips and ragged edges . 6 4.1.1 Chips and ragged edges loc
19、ated on the mating surface . 6 4.1.2 Chips located on other surfaces . 6 4.2 Cracks 9 4.3 Pull-out . 10 4.4 Crystallites 10 4.5 Flash 11 4.6 Pores 11 Bibliography 13 Figure 1 Examples of surface irregularities 5 Figure 2 Chips and ragged edges location . 6 Figure 3 Cracks location 9 Figure 4 Referen
20、ce dimensions for PQ-cores . 9 Figure 5 Pull-out location . 10 Figure 6 Crystallites location 11 Figure 7 Flash location. 11 Figure 8 Pores location 12 Table 1 Limits for allowable chipping areas 7 Table 2 Area and length reference of irregularities for visual inspection . 8 Table 3 Limits for crack
21、s 10 BS EN 60424-8:2015IEC 60424-8:2015 IEC 2015 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ FERRITE CORES GUIDELINES ON THE LIMITS OF SURFACE IRREGULARITIES Part 8: PQ-cores FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
22、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,
23、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
24、 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
25、. 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
26、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
27、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
28、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
29、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
30、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
31、 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
32、e for identifying any or all such patent rights. International Standard IEC 60424-8 has been prepared by technical committee 51: Magnetic components and ferrite materials. The text of this standard is based on the following documents: CDV Report on voting 51/1078/CDV 51/1084/RVC Full information on
33、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. BS EN 60424-8:2015 4 IEC 60424-8:2015 IEC 2015 A list of all parts in the IEC 60424 series, published u
34、nder the general 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
35、committee has decided 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 e
36、dition, or amended. BS EN 60424-8:2015IEC 60424-8:2015 IEC 2015 5 FERRITE CORES GUIDELINES ON THE LIMITS OF SURFACE IRREGULARITIES Part 8: PQ-cores 1 Scope This part of IEC 60424 gives guidance on allowable limits of surface irregularities applicable to PQ-cores in accordance with the relevant gener
37、ic specification. This standard is considered as a sectional specification useful in the negotiation between ferrite core manufacturers and users about surface irregularities. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are ind
38、ispensable 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. IEC 60401-1, Terms and nomenclature for cores made of magnetically soft ferrites Part 1: Terms used for phys
39、ical irregularities IEC 60424-1, Ferrite cores Guide on the limits of surface irregularities Part 1: General specification 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60424-1 and IEC 60401-1, as well as the following apply. 3.1 pores holes left o
40、n the surface of cores after sintering and surface finishing SEE: Figure 1. Figure 1 Examples of surface irregularities IEC BS EN 60424-8:2015 6 IEC 60424-8:2015 IEC 2015 4 Limits of surface irregularities 4.1 Chips and ragged edges 4.1.1 Chips and ragged edges located on the mating surface The area
41、s of the chips located on the mating surface (see C1 and C1 irregularities in Figure 2) shall not exceed the following limits: the cumulative area of the chips located on the mating surface shall be less than 4 % of the total mating surface; the cumulative area of the chips located on the centre pos
42、t mating surface shall be less than 2 % of the total mating surface; the cumulative area of the chips located on the mating surface of one outer leg shall be less than 1 % of the total mating surface; The total length of the ragged edges shall be less than 25 % of the perimeter of the relevant matin
43、g surface. 4.1.2 Chips located on other surfaces The areas of the chips located on the other surfaces (see C2, C2, C3 and C3 irregularities in Figure 2) shall not exceed the following limits: the allowable chipping areas are doubled as compared to the limits for the whole mating surfaces (see Table
44、1); the rule for the ragged edges is the same as for the mating surfaces; chips and ragged edges are not acceptable on the inner edges of the wire slot area. Figure 2 Chips and ragged edges location The limits of allowable chipping areas shall be in accordance with Table 1. IEC BS EN 60424-8:2015IEC
45、 60424-8:2015 IEC 2015 7 Table 1 Limits for allowable chipping areas Unit: mm2Core size Chipping on mating surface of one outer leg Chipping on mating surface of centre post Overall chipping on mating surface Overall chipping on other surfaces PQ20/16 1,0 2,0 4,5 9,0 PQ20/20 1,0 2,0 4,5 9,0 PQ26/20
46、2,0 4,5 9,5 19,0 PQ26/25 2,0 4,5 9,5 19,0 PQ32/20 3,0 6,0 12,0 24,0 PQ32/30 3,0 6,0 12,0 24,0 PQ35/35 3,0 6,5 13,0 26,0 PQ40/40 3,5 7,0 14,0 28,0 PQ50/50 6,0 12,5 25,0 50,0 NOTE For the relevant core sizes refer to IEC 62317-13. The area and length reference of irregularities for visual inspection a
47、re given in Table 2. BS EN 60424-8:2015 8 IEC 60424-8:2015 IEC 2015 Table 2 Area and length reference of irregularities for visual inspection IEC BS EN 60424-8:2015IEC 60424-8:2015 IEC 2015 9 4.2 Cracks Figure 3 shows examples of cracks location on PQ-cores: a single crack which intersects the perim
48、eter of the relevant surface at two points is not acceptable (see S1 in Figure 3); the number of the cracks located on the same surface shall not exceed 3. The limits of cracks at various locations shown in Figure 3 are given in Table 3. Key S1 to S8: types of cracks (for limits for cracks, see Tabl
49、e 3) Figure 3 Cracks location The reference dimensions for PQ-cores given in Figure 4 correspond to the cores defined in IEC 60401-2. Key A Overall length of the core back B Outside leg length of core C Core width D Inside leg length or available bobbin depth F Centre post diameter Figure 4 Reference dimensions for PQ-cores IEC IEC BS EN 60424-8:2015 10 IEC 60424-8:2015 IEC 2015 Table 3 Limits for cracks TypeaLocation
