1、BRITISH STANDARD BS 2857:1976 Specification for Nickel-iron transformer and choke laminations UDC 621.314.042.2:669.2451BS2857:1976 This British Standard, having been prepared under the directionof the Telecommunication Industry Standards Committee, was published under the authority ofthe Executive
2、Board on 29 October1976 BSI 12-1999 First published May 1957 First revision October 1976 The following BSI references relate to the work on this standard: Committee referenceTLE/20/1 Draft for comment73/76256 and draft for approval75/28852 ISBN 0 580 09136 8 Cooperating organizations The Telecommuni
3、cation Industry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: British Broadcasting Corporation* British Electrical and Allied Manufacturers Associatio
4、n* British Electrotechnical Approvals Board for Household Equipment British Radio Equipment Manufacturers Association British Railways Board Cable Television Association of GreatBritain Cable and Wireless Ltd. Crown Agents for Oversea Governments and Administrations Department of Prices and Consumer
5、 Protection Electrical Contractors Association Electrical Research Association Electricity Supply Industry in England and Wales Electronic Components Board Electronic Engineering Association* Health and Safety Executive Institution of Electrical and Electronics Technicians Engineers Institution of E
6、lectrical Engineers Institution of Electronic and Radio Engineers Institution of Production Engineers Ministry of Defence* Post Office Radio and Electronic Component Manufacturers Federation* Science Research Council Radio and Space Research Station Scientific Instrument Manufacturers Association So
7、ciety of British Aerospace Companies Ltd.* Telecommunication Engineering and Manufacturing Association* The Government department and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted w
8、ith the preparation of this British Standard: British Steel Corporation Engineering Equipment Users Association National Supervising Inspectorate Sheet Makers Conference Telephone Manufacturers Technical Development Committee Transmission Distribution Association UnitedKingdom Atomic Energy Authorit
9、y Amendments issued since publication Amd. No. Date of issue CommentsBS2857:1976 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Physical and mechanical characteristics 2 5 Magnetic characteristics 10 Appendix A Method f
10、or the calculations of effective parameters 25 Figure 1 Test coil and clamping device for measurements of EI,EE,EE(L)andED range laminations 16 Figure 2 Test coil and clamping device for measurements on FandF(L)rangelaminations 16 Figure 3 Impedance bridge circuit for the measurement of equivalentpe
11、rmeability 17 Figure 4 Bridge circuit for the measurement of equivalent parallelresistance 20 Figure 5 Circuit for the measurement of remanence ratio 23 Figure 6 Circuit for the measurement of incremental permeability 24 Figure 7 Magnetic circuit elements 25 Table 1 Material classification 2 Table 2
12、 Dimensions of EI range laminations 3 Table 3 Dimensions of EE range laminations 4 Table 4 Dimensions of F range laminations 5 Table 5 Dimensions of E range laminations 6 Table 6 Dimensions of ED range laminations 7 Table 7 Dimensions of EE(L) range laminations 8 Table 8 Dimensions of F(L) range lam
13、inations 9 Table 9 Thickness and burr limits 9 Table 10 Minimum space factor 9 Table 11 Core constants for EI range laminations 11 Table 12 Core constants for EE and F range laminations 12 Table 13 Core constants for E range laminations 13 Table 14 Core constants for ED range laminations 14 Table 15
14、 Core constants for EE(L) and F(L) range laminations 15 Table 16 Minimum permeability for EI range laminations 18 Table 17 Minimum permeability for EE range laminations 18 Table 18 Minimum permeability for E range laminations 19 Table 19 Minimum permeability for ED range laminations 19 Table 20 Mini
15、mum permeability for EE(L) range laminations 20 Table 21 Minimum equivalent parallel resistance coefficient forEIrangelaminations, m7/turn 2 21 Table 22 Minimum equivalent parallel resistance coefficient forEErangelaminations, m7/turn 2 21 Table 23 Minimum equivalent parallel resistance coefficient
16、forErangelaminations, m7/turn 2 22BS2857:1976 ii BSI 12-1999 Page Table 24 Minimum equivalent parallel resistance coefficient forEDrangelaminations, m7/turn 2 22 Table 25 Minimum equivalent parallel resistance coefficient forEE(L)rangelaminations, m7/turn 2 23 Table 26 Minimum remanence ratio for ED
17、 range laminations 24 Publications referred to 26BS2857:1976 BSI 12-1999 iii Foreword This British Standard was originally published in1957 under the authority of the Iron and Steel Industry Standards Committee. This revised edition has been prepared under the authority of the Telecommunication Indu
18、stry Standards Committee. New lamination ranges (based on IEC; recommendations) and requirements for additional magnetic characteristics are included; the requirements for the permeability of laminations and the description of suitable test methods are more comprehensively treated; and opportunity h
19、as been taken to give metric values of the dimensions of laminations. Certification. Attention is drawn to the certification facilities described on theinside back cover of this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Stan
20、dards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to26, an inside back cover and a back cover. This stand
21、ard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS2857:1976 BSI 12-1999 1 1 Scope This British Standard specifies essential requirements, test procedures and other information relating
22、 to non-oriented and oriented nickel-iron laminations intended for cores for transformer and inductor applications. The surface of laminations is normally oxide coated, but an additional surface coating (e.g.paint or lacquer) may be required by the customer (see4.3). 2 References The titles of the p
23、ublications referred to in this standard are listed on page 26. 3 Definitions For the purposes of this British Standard the following definitions apply, in addition to those included inBS4727-1:Group07. 3.1 effective permeability a parameter of a magnetic circuit that equals the permeability of a hy
24、pothetical magnetic circuit of homogeneous construction having the same shape, dimensions and total reluctance. It is defined under stated conditions by the equation where L (H) is the equivalent series inductance of a coil of N turns associated with a core having a core factorC 1 (m 1 ) and 4 0=4;.
25、10 7H.m 1 3.2 core factor C 1 a factor related to the geometry of a magnetic circuit, calculated by the method given in Appendix A, defined by the equation where is the ratio of magnetic path length (=) to the corresponding cross-sectional area of the core (A) 3.3 core factor C 2 a factor related to
26、 the geometry of a magnetic circuit, calculated by the method given in Appendix A, defined by the equation where is the ratio of magnetic path length (=) to the square of the corresponding cross-sectional area of the core (A) 3.4 effective length = e a derived magnetic path length related to the geo
27、metry of a magnetic circuit, calculated by the method given inAppendix A, defined by the equation = e= C 1 2 /C 1 3.5 effective area A e a derived magnetic path related to the geometry of a magnetic circuit, calculated by the method given inAppendix A, defined by the equation A e= C 1 /C 2 3.6 space
28、 factor the ratio of iron area to total stack area in a cross section perpendicular to the surface of the laminations 3.7 square stack the smallest number of laminations the height of which is, under a specified pressure, not less than the maximum width of the centre limb 3.8 equivalent parallel res
29、istance coefficient the ratio of that equivalent parallel resistance which will dissipate the same total power as the inductor (under stated conditions of measurement) to the square of the number of turns 3.9 remanence ratio the ratio of remanence (see2026 ofBS4727-1: Group07) to flux density at sat
30、uration when measured from a specified peak magnetizing force 3.10 peak flux density the peak value of periodic effective flux density in a core assembly given by the equation = A - = A 2 -BS2857:1976 2 BSI 12-1999 where 4 Physical and mechanical characteristics 4.1 Material. The laminations shall b
31、e made from material that falls into one of the classes described inTable 1. Table 1 Material classification 4.2 Dimensions. The laminations shall have physical dimensions in accordance withTable 2 toTable 8 (as appropriate). In each case, the profile shall be symmetrical about datum width a. These
32、are based on IEC Recommendations for the dimensions of laminations and are arranged as follows. NOTE 1The method of dimensional tolerancing is in accordance withBS4500. Tolerance codes H12 and h12 apply to dimensions up to10mm; H11 and h11 to dimensions between10mm and80mm; H10 and h10 to dimensions
33、 greater than80mm. NOTE 2Any holes and/or notches in laminations (if required by the customer) may alter the magnetic characteristics (seeclause5). B e is the peak value of effective flux density (inT) E av is the value of the e.m.f.averaged over one half a cycle (in V) f is the a.c.frequency (in Hz
34、) N is the number of turns of the test coil A e is the effective cross-sectional area of the magnetic bath (inmm 2 ) Class Approximate composition range Specific gravity A 75% to80% nickel plus additions, the bulk of which isiron 8.8 B1 and B2 a 45% to50% nickel plus additions, the bulk of which is
35、iron 8.3 C 34% to38% nickel plus additions, the bulk of which is iron 8.1 D b Grain oriented45% to50% nickel, the balance being iron 8.3 a B2 material has a substantially higher permeability than B1. b D material is normally used only in special shapes (e.g.the ED range of laminations) to take advan
36、tage of its square hysteresis loop characteristics. Table 2: EI range Table 3: EE range Table 4: F range Table 5: E range Table 6: ED range Table 7: EE(L) range Table 8: F(L) rangeBS2857:1976 BSI 12-1999 3 Table 2 Dimensions of EI range laminations All dimensions are in millimetres. Designation a b
37、c d e r Sym. tol. max. min. max. min. max. min. max. min. max. min. max. width EI 10 30.13 30.0 20.13 20.0 15.11 15.0 10.0 9.85 20.13 20.0 0.02 0.055 EI 12.8 38.56 38.4 25.73 25.6 19.33 19.2 12.8 12.69 25.73 25.6 0.025 0.055 EI 14 a 42.16 42.0 28.13 28.0 21.13 21.0 14.0 13.89 28.13 28.0 0.025 0.055
38、EI 16 a 48.16 48.0 32.16 32.0 24.13 24.0 16.0 15.89 32.16 32.0 0.025 0.06 EI 18 a 54.19 54.0 36.16 36.0 27.13 27.0 18.0 17.89 36.16 36.0 0.025 0.06 EI 20 a 60.19 60.0 40.16 40.0 30.16 30.0 20.0 19.87 40.16 40.0 0.032 0.065 EI 25 a 75.19 75.0 50.19 50.0 37.66 37.5 25.0 24.87 50.19 50.0 0.032 0.065 EI
39、 32 96.14 96.0 64.19 64.0 48.16 48.0 32.0 31.84 64.19 64.0 0.04 0.08 a Indicates preferred type.BS2857:1976 4 BSI 12-1999 Table 3 Dimensions of EE range laminations All dimensions are in millimetres. Designation a b 1 b 2 c 1 c 2 d e r Sym. tol. max. min. max. min. max. min. max. min. max. min. max.
40、 min. max. min. max. width EE 2.4 8.15 8.0 5.42 5.3 2.8 2.7 4.22 4.1 1.6 1.5 2.4 2.3 5.72 5.6 0.01 0.05 EE 3.0 10.11 10.0 6.85 6.7 3.42 3.3 5.32 5.2 1.9 1.8 3.0 2.9 7.15 7.0 0.01 0.05 EE 3.8 12.71 12.6 8.55 8.4 4.32 4.2 6.65 6.5 2.4 2.3 3.8 3.68 8.95 8.8 0.015 0.055 EE 4.8 16.11 16.0 10.81 10.7 5.42
41、 5.3 8.45 8.3 3.0 2.9 4.8 4.68 11.31 11.2 0.015 0.055 EE 6.0 20.13 20.0 13.41 13.3 6.85 6.7 10.41 10.3 3.82 3.7 6.0 5.88 14.11 14.0 0.015 0.06 EE 7.6 25.13 25.0 16.81 16.7 8.45 8.3 13.01 12.9 4.62 4.5 7.6 7.45 17.51 17.4 0.02 0.06 EE 9.6 32.16 32.0 21.43 21.3 10.81 10.7 16.61 16.5 6.02 5.9 9.6 9.45
42、22.53 22.4 0.02 0.065 EE 12 40.16 40.0 26.83 26.7 13.41 13.3 20.83 20.7 7.45 7.3 12.0 11.89 28.13 28.0 0.025 0.065 EE 15 50.19 50.0 33.46 33.3 16.81 16.7 25.95 25.8 9.35 9.2 15.0 14.89 35.16 35.0 0.025 0.07 EE 19 64.19 64.0 42.86 42.7 21.43 21.3 33.36 33.2 11.91 11.8 19.0 18.87 45.16 45.0 0.032 0.07
43、 EE 24 80.14 80.0 53.49 53.3 26.83 26.7 41.46 41.3 14.81 14.7 24.0 23.87 56.19 56.0 0.032 0.075 EE 30 100.14 100.0 66.89 66.7 33.46 33.3 51.89 51.7 18.43 18.3 30.0 29.87 70.19 70.0 0.032 0.075 EE 38 126.16 126.0 84.14 84.0 42.16 42.0 65.19 65.0 23.13 23.0 38.0 37.84 88.14 88.0 0.04 0.08BS2857:1976 B
44、SI 12-1999 5 Table 4 Dimensions of F range laminations All dimensions are in millimetres. Designation a b 1 b 2 b 3 c d e r Sym. tol. max. min. max. min. max. min. max. min. max. min. max. min. max. min. max. width F 2.4 8.15 8.0 4.12 4.0 5.3 5.18 2.7 2.6 2.9 2.8 2.4 2.3 5.72 5.6 0.01 0.05 F 3.0 10.
45、11 10.0 5.12 5.0 6.7 6.55 3.3 3.18 3.6 3.5 3.0 2.9 7.15 7.0 0.01 0.05 F 3.8 12.71 12.6 6.45 6.3 8.4 8.25 4.2 4.08 4.52 4.4 3.8 3.68 8.95 8.8 0.015 0.055 F 4.8 16.11 16.0 8.15 8.0 10.7 10.59 5.3 5.18 5.7 5.6 4.8 4.68 11.31 11.2 0.015 0.055 F 6.0 20.13 20.0 10.11 10.0 13.3 13.19 6.7 6.55 7.15 7.0 6.0
46、5.88 14.11 14.0 0.015 0.06 F 7.6 25.13 25.0 12.61 12.5 16.7 16.59 8.3 8.15 8.85 8.7 7.6 7.45 17.51 17.4 0.02 0.06 F 9.6 32.16 32.0 16.11 16.0 21.3 21.17 10.7 10.59 11.31 11.2 9.6 9.45 22.53 22.4 0.02 0.065 F 12 40.16 40.0 20.13 20.0 26.7 26.57 13.3 13.19 14.11 14.0 12.0 11.89 28.13 28.0 0.025 0.065
47、F 15 50.19 50.0 25.13 25.0 33.3 33.14 16.7 16.59 17.61 17.5 15.0 14.89 35.16 35.0 0.025 0.07 F 19 64.19 64.0 32.16 32.0 42.7 42.54 21.3 21.17 22.63 22.5 19.0 18.87 45.16 45.0 0.032 0.07 F 24 80.14 80.0 40.16 40.0 53.3 53.11 26.7 26.57 28.13 28.0 24.0 23.87 55.19 56.0 0.032 0.075 F 30 100.14 100.0 50
48、.19 50.0 66.7 66.51 33.3 33.14 35.16 35.0 30.0 29.87 70.19 70.0 0.032 0.075 F 38 126.16 126.0 63.19 63.0 84.0 83.86 42.0 41.84 44.16 44.0 38.0 37.84 88.14 88.0 0.04 0.08BS2857:1976 6 BSI 12-1999 Table 5 Dimensions of E range laminations All dimensions are in millimetres. Designation a b c d e r Sym.
49、 tol. max. min. max. min. max. min. max. min. max. min. max. width E 2.4 8.15 8.0 8.15 8.0 6.95 6.8 2.4 2.3 5.72 5.6 0.01 0.05 E 3.0 10.11 10.0 10.11 10.0 8.65 8.5 3.0 2.9 7.15 7.0 0.01 0.05 E 3.8 12.71 12.6 12.71 12.6 10.81 10.7 3.8 3.68 8.95 8.8 0.015 0.055 E 4.8 16.11 16.0 16.11 16.0 13.71 13.6 4.8 4.68 11.31 11.2 0.015 0.055 E 6.0 20.13 20.0 20.13 20.0 17.11 17.0 6.0 5.88 14.11 14.0 0.015 0.06 E 7.6 25.13 25.0 25.13 25.0 21.33 21.2 7.6 7.45 17.51 17.4 0.02 0.06 E 9.6 32.16
