BS IEC 1000-5-4-1996 Electromagnetic compatibility (EMC) - Installation and mitigation guidelines - Immunity to HEMP - Specifications for protective devices against HEMP radiated d.pdf

1、BRITISH STANDARD BS IEC 1000-5-4:1996 Implementation of IEC 1000-5-4:1996 Electromagnetic compatibility (EMC) Part 5: Installation and mitigation guidelines Section 4. Immunity to HEMP Specifications for protective devices against HEMP radiated disturbance Basic EMC publication ICS 33.100BSIEC 1000-

2、5-4:1996 This British Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 December 1996 BSI 10-1998 The following BSI references relate to the work on this standard: Committee re

3、ference GEL/210 Draft for comment 92/04372 DC ISBN 0 580 26811 X Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee GEL/210, Electromagnetic compatibility, upon which the following bodies were represented: Association of Con

4、sulting Scientists Association of Control Manufacturers (TACMA (BEAMA Ltd.) Association of Manufacturers of Domestic Electrical Appliances Association of Manufacturers of Power Generating Systems BEAMA Ltd. BEAMA Metering Association (BMA) British Industrial Truck Association British Lighting Associ

5、ation for the Preparation of Standards (BRITLAPS) British Telecommunications plc Building Automation and Mains Signalling Association (BAMSA) (BEAMA Ltd.) Department of Health Department of Trade and Industry (Standards Policy Unit) Electrical Installation Equipment Manufacturers Association (BEAMA

6、Ltd.) Electricity Association ERA Technology Ltd. Federation of the Electronics Industry GAMBICA (BEAMA Ltd.) Health and Safety Executive Induction and Dielectric Heating Manufacturers Association Institution of Electrical Engineers International Association of Broadcasting Manufacturers Lighting In

7、dustry Federation Ltd. Ministry of Defence Motor Industry Research Association National Air Traffic Services National Physical Laboratory Power Supply Manufacturers Association (PSMA (BEAMA Ltd.) Professional Lighting and Sound Association Radiocommunications Agency Rotating Electrical Machines Asso

8、ciation (BEAMA Ltd.) Society of British Gas Industries Society of Motor Manufacturers and Traders Limited Transmission and Distribution Association (BEAMA Ltd.) Amendments issued since publication Amd. No. Date CommentsBSIEC1000-5-4-1996 BSI 10-1998 i Contents Page Committees responsible Inside fron

9、t cover National foreword ii Foreword iii Text of CEI IEC 1000-5-4 1BSIEC1000-5-4-1996 ii BSI 10-1998 National foreword This British Standard reproduces verbatim IEC 1000-5-4:1996 and implements it as the UK national standard. This British Standard is published under the direction of the Electrotech

10、nical Sector Board whose Technical Committee GEL/210 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and Europea

11、n developments and promulgate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of

12、 British Standards 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, pages i and ii, theCEI IEC title page, pages 2 to 18 and a ba

13、ck cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.BSIEC 1000-5-4:1996 ii BSI 10-1998 Contents Page Foreword iii 1 Scope 1 2 Normative reference 1 3 Definitions 1 4 Specificati

14、ons for protective devices against radiated disturbances 2 4.1 General classification for shielding devices 2 4.2 General requirements 2 4.3 Specifications 3 4.3.1 General 3 4.3.2 Barrier materials 3 4.3.3 Shielded cables and conduits 7 4.3.4 Gasketing materials 10 4.3.5 Shielding components 11 Anne

15、x A (informative) General theory 12 Annex B (informative) Bibliography 18 Figure 1 Typical plane wave attenuation for double-wall cages 3 Figure 2 Example of HEMP shielding effectiveness of a Faraday cage 4 Figure 3 Example of attenuation of a cabinet with gaskets 5 Figure 4 Example of magnetic fiel

16、d attenuation function of a viewing window 6 Figure 5 Experimental transfer impedances 8 Figure 6 Example of transfer impedance of a braided-wire shield 9 Figure 7 Example of transfer impedance computed for a tape-wound shield 10 Figure A.1 Theoretical reflection (R db ) for copper and iron 13 Figur

17、e A.2 Theoretical composite reflection (R db ) and absorption (A db ) for copper and iron 14 Figure A.3 Transfer impedance definition 16 Figure A.4 Equivalent circuit describing the effects of the transfer impedance and of the transfer admittance 16 Figure A.5 Variation of the eccentricity function

18、for braided wire shields 17BSIEC1000-5-4:1996 BSI 10-1998 iii Foreword 1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote internation

19、al cooperation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, the IEC publishes International Standards. Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject

20、 dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions de

21、termined by agreement between the two organizations. 2) The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on which all the National Committees having a special interest therein are represented, express, as nearly as possible, an international consen

22、sus of opinion on the subjects dealt with. 3) They have the form of recommendations for international use published in the form of standards, technical reports or guides and they are accepted by the National Committees in that sense. 4) In order to promote international unification, IEC National Com

23、mittees undertake to apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter. 5) Attention is drawn to

24、 the possibility that some of the elements of this International Standard may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. 6) The IEC has not laid down any procedure concerning marking as an indication of approval and has no respon

25、sibility when an item of equipment is declared to comply with one of its standards. The main task of IEC technical committees is to prepare International Standards. In exceptional circumstances, a technical committee may propose the publication of a technical report of one of the following types: ty

26、pe 1, when the required support cannot be obtained for the publication of an International Standard, despite repeated efforts; type 2, when the subject is still under technical development or where for any other reason there is the future but not immediate possibility of an agreement on an Internati

27、onal Standard; type 3, when a technical committee has collected data of a different kind from that which is normally published as an International Standard, for example “state of the art”. Technical reports of types 1 and 2 are subject to review within three years of publication to decide whether th

28、ey can be transformed into International Standards. Technical reports of type 3 do not necessarily have to be reviewed until the data they provide are considered to be no longer valid or useful. IEC 1000-5-4, which is a technical report of type 2, has been prepared by subcommittee 77C: Immunity to h

29、igh altitude nuclear electromagnetic pulse (HEMP), of IEC technical committee 77: Electromagnetic compatibility. The text of this this technical report is based on the following documents: FDIS Report on voting 77C/26/CDV 77C/36/RVCBSIEC 1000-5-4:1996 iv BSI 10-1998 Full information on the voting fo

30、r the approval of this technical report can be found in the report on voting indicated in the above table. Annexes A and B are for information only. This document is issued in the type 2 Technical Report series of publications (according to G.4.2.2 of part 1 of the IEC/ISO Directives as a “prospecti

31、ve standard for provisional application” in the field of electromagnetic compatibility because there is an urgent requirement for guidance on how standards in this field should be used to meet an identified need. This document is not to be regarded as an “International Standard”. It is proposed for

32、provisional application so that information and experience of its use in practice may be gathered. Comments on the content of this document should be sent to the IEC Central Office. A review of this type 2 Technical Report will be carried out not later than three years after its publication, with th

33、e options of either extension for a further three years or conversion to an International Standard or withdrawal.BSIEC1000-5-4:1996 BSI 10-1998 1 1 Scope This technical report defines how protective devices for High Altitude Nuclear Electromagnetic Pulse (HEMP) protection of civilian systems are spe

34、cified. Performance requirements will be given in future IEC standards. This technical report is intended to be used for the harmonization of existing or future specifications issued by protective devices manufacturers, electronic equipment manufacturers, administrative bodies and other buyers. This

35、 technical report covers protective devices currently used for protection against HEMP radiated EM fields. In general, parameters relevant to HEMP, that is parameters related to very fast changes of EM fields, as a function of time, are dealt with. 2 Normative reference The following normative docum

36、ent contains provisions which, through reference in this text, constitute provisions of this technical report. At the time of publication, the edition indicated was valid. All normative documents are subject to revision, and parties to agreements based on this technical report are encouraged to inve

37、stigate the possibility of applying the most recent edition of the normative document indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 50(161):1990, International Electrotechnical Vocabulary (IEV) Chapter 161: Electromagnetic compatibility. 3

38、 Definitions For the purpose of this technical report, the following definitions apply. HEMP/HA-NEMP the two acronyms are equivalent and accepted for High Altitude Nuclear Electromagnetic Pulse. HEMP is preferable to HA-NEMP barrier separation used to insulate electrical circuits from electromagneti

39、c disturbances (A shield is a special type of barrier.) contact resistance resistance measured in ohms between two objects in contact with each other compression set the per cent of permanent height reduction in a material caused by compression under specific conditions of heat, pressure and time co

40、rrosion resistance resistance to a chemical action which causes gradual destruction of the surface of a metal by oxidation, electrolysis or chemical contamination cut-off frequency the frequency at which the magnitude of a measured characteristic quantity has decreased to a specified fraction of its

41、 low-frequency value NOTEFor a waveguide it is the frequency below which electromagnetic energy is not efficiently propagated in the guide. This frequency depends on the cross-section geometry and dimensions of the guide. elongation the increase in length of a material stressed under tension point o

42、f entry the physical place at the surface of a closed enclosure through which the energy penetrates protective device an electrical component such as a filter, gas discharge tube, metal oxide varistor, etc., for protection against conducted disturbances, or a shield, gasket, waveguide trap, etc., fo

43、r protection against radiated disturbances. Such an element, or a combination of several of them, thus forms part of the conceptual electromagnetic barrier of the system shield electrically conductive material placed around a system circuit, component, or cable to suppress the effect of an electroma

44、gnetic field within or beyond definite regions shielding effectiveness the measure, generally in dB, of the reduction or attenuation of the amplitude of an electromagnetic field at a point in space before and after the placement of a shield, between a source and this point skin depth the depth of a

45、conductive material beyond which thecurrent density has decreased by one Neper(1/e or36,8%) in comparison with its value atthe surface of the material surface resistivity the resistance of a material between two opposite sides of a unit square of its surface, commonly expressed in ohms per square su

46、rface transfer impedance (of a coaxial line) the quotient of the voltage induced in the centre conductor of a coaxial line per unit length by the current on the external surface of the coaxial line IEV 161-04-15BSIEC 1000-5-4:1996 2 BSI 10-1998 tensile strength the maximum tensile stress applied, du

47、ring stretching, to a specimen to rupture transfer admittance a mathematical relationship between the induced current on a conductor located on the protected side of a shielded region and the voltage on the unprotected side of the enclosure. This is the dual quantity of the transfer impedance transf

48、er impedance (of a screened circuit) the quotient of the voltage appearing between two specified points in the screened circuit by the current in a defined cross-section of the screen IEV161-04-14 volume resistivity the electrical resistance between opposite faces of1cm 3of material, commonly expres

49、sed in ohms.centimetres waveguide below cut-off a protective element consisting of a length of waveguide which limits the passage of electromagnetic energy below a fixed frequency waveguide trap a waveguide below cut-off serving as an electromagnetic protection device in a barrier 4 Specifications for protective devices against radiated disturbances The shielding effectiveness of a shielded enclosure (Faraday cage, cabinet or shielded building) is violated by penetrations, openings and seams. All of these shall be treated i