EN 2853-2005 en Current ratings for electrical cables with conductor EN 2083《导体EN 2083的电缆的额定电流》.pdf

1、BRITISH STANDARD AEROSPACE SERIESBS EN 2853:2005Current ratings for electrical cables with conductor EN 2083The European Standard EN 2853:2005 has the status of a British StandardICS 49.060g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g5

2、1g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 2853:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 2 March 2006 BSI 2 March 2006ISBN 0 580 47916 1National forewordThis British Standard is t

3、he official English language version of EN 2853:2005.The UK participation in its preparation was entrusted to Technical Committee ACE/6, Aerospace avionic electrical and fibre optic technology, which has the responsibility to: A list of organizations represented on this committee can be obtained on

4、request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI

5、 Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers

6、 to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document compr

7、ises a front cover, an inside front cover, the EN title page, pages 2 to 10, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNE

8、EUROPISCHE NORMEN 2853October 2005ICS 49.060English VersionAerospace series - Current ratings for electrical cables withconductor EN 2083Srie arospatiale - Intensits admissibles dans les cbleslectriques conducteur EN 2083Luft- und Raumfahrt - Strombelastbarkeit von elektrischenLeitungen mit Leiter n

9、ach EN 2083This European Standard was approved by CEN on 19 September 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliogr

10、aphical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN

11、 member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Li

12、thuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All ri

13、ghts of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 2853:2005: E2 Contents Page Foreword 3 1 Scope .4 2 Normative references .4 3 Terms and definitions.5 4 Rationale5 5 Tabulated data.6 Annex A (informative) Supplementary notes .8 Annex B (normati

14、ve) Current rating tests 9 EN 2853:20053 Foreword This European Standard (EN 2853:2005) has been prepared by the European Association of Aerospace Manufacturers - Standardization (AECMA-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has r

15、eceived the approval of the National Associations and the Official Services of the member countries of AECMA, prior to its presentation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by Apri

16、l 2006, and conflicting national standards shall be withdrawn at the latest by April 2006. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rig

17、hts. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvi

18、a, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 2853:20054 1 Scope 1.1 This standard specifies current rating data for cables produced with conductors as defined in EN 2083. 1.2 Electrical ratings for c

19、ontinuous and short term conditions are tabulated such that the requirements of EN 3197 are satisfied. 1.3 A procedure for establishing cable current ratings is given in Annex B of this specification. 1.4 The basis for determining current of cables has been to employ a 40 C rise as the electrical co

20、ntribution to operating temperature. Note is made in this standard that, in practice, the voltage drop requirements of EN 2282 will often dictate lower current densities. Additionally, reference to appropriate aerospace series standards for cable terminations and connectors will show constraints whi

21、ch may dictate cable size. 1.5 It is stressed that the current ratings given in this document relate solely to copper and copper alloy conductors as defined in EN 2083. The values are based upon historical evidence and are subject to the caveat given in 4.1. Accordingly the acceptance of data withou

22、t verification in any particular case is a matter of discretion by both the aircraft design and certification authorities. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undat

23、ed references, the latest edition of the referenced document (including any amendments) applies. EN 2083, Aerospace series Copper or copper alloy conductors for electrical cables Product standard. EN 2282, Aerospace series Characteristics of aircraft electrical supplies. EN 3197, Aerospace Series In

24、stallation of aircraft electrical and optical interconnection systems. 1)EN 3475-100, Aerospace series Cables, electrical, aircraft use Test methods Part 100: General. 1) Published as AECMA Prestandard at the date of publication of this standard. EN 2853:20055 3 Terms and definitions For the purpose

25、s of this document, the terms and definitions given in EN 3475-100, EN 3197 and the following apply. 3.1 Tu the unpowered conductor temperature of a cable when in an operating environment 3.2 Tr the maximum rated temperature of a cable. Operation at or below this temperature by any combination of el

26、ectrical heating and ambient condition shall not be prejudicial to design life 3.3 duty cycle rating the load current which may be passed through a cable for the duration stated without causing the specified value of Tr to be exceeded 4 Rationale 4.1 It is recognized that the determination of precis

27、e current ratings for every cable construction and size can be shown to be a complex matter. Factors such as the thermal conductivity and thickness of insulation, test methods and the criteria employed will all have some effect. The intent of this standard is that the data presented should be suffic

28、iently accurate to permit good engineering judgement to be exercised in the context of EN 3197. However, to enable verification of precise cable rating as noted in Clause 1, a preferred method of measurement is given in Annex B of this standard. 4.2 Cable current ratings are provided, primarily to f

29、acilitate selection of the appropriate size to carry a given load. These ratings are also employed to assist, but not solely to determine, the setting of electrical protection levels. Historically some agencies have specified short term current ratings in cable specifications and such data represent

30、ed current values and durations which were deemed to be just below the overload damage point. Implicitly these were fault conditions and were to be experienced on only rare occasions. In this standard this approach has been changed and the short term ratings given herein are those which may be emplo

31、yed within a duty cycle, without prejudice to installed life. As noted in Clause 1, cable rating has been determined as that current which will cause conductor temperature to rise by 40 C and therefore this same value has been employed for short term ratings. 4.3 Annex A of this specification provid

32、es supplementary notes to the foregoing clauses. EN 2853:20056 5 Tabulated data 5.1 Current ratings See Table 1. Table 1 Current ratings for aircraft cable with copper conductors Duty cycle ratings A Code Size AWG 2 s 10 s 1 min Continuous ratings aA 001 b26 b13,0 6,7 4,8 4,8 002 b24 b19,5 9,5 6,5 6

33、,5 004 22 23,0 12,0 8,5 8,5 006 20 39,0 20,0 11,5 11,5 010 18 58,0 30,0 16,0 15,0 012 16 81,5 41,0 21,5 19,5 020 14 105 53,0 28,0 24,0 030 12 160 82,0 43,5 35,0 050 10 245 125 52,8 43,0 090 8 420 215 94,5 68,0 140 6 587 300 135 85,0 220 4 890 450 202 115 340 2 1340 690 325 166 530 0 2015 1020 460 21

34、6 aTake care of compatibility between load current of cables and that employed for terminations and circuit breakers. bCopper alloy conductors. NOTE 1 The Duty cycle ratings and the continuous ratings are current values which may be employed without detriment to normal life. They have been determine

35、d from cables rates at a Tr of 135 C which have been heated by electrical loading from a Tu of 95 C. These 40 C temperature rise data are for single cables in free air but are generally applicable as noted in 1 and 4 and Annex A of this specification. NOTE 2 Approximate current ratings which corresp

36、ond to a conductor temperature rise of dT of other than 40 C may be calculated by applying the following formula: I2= I140Tu -TrWhere I1 is the rated current to give 40 C rise, see Table 1; I2 is the new rating; Tr is the rated temperature; Tu is the unpowered conductor temperature (local ambient).

37、NOTE 3 Annex B of this specification describes a test method for determining current rating of cables and formula for the interpretation of results. EN 2853:20057 5.2 Voltage drop at rated current Table 2 lists the voltage drop obtained for a range of cable sizes when operated singly in free air suc

38、h that a temperature rise of 40 C is obtained from an unpowered temperature Tu of 95 C (as in Table 1). The voltage drop figures are for a 10 m length. Table 2 Voltage drop at rated current Code Size AWG Continuous current rating A Voltage drop for 10 m at conductor temperature of 135 C 001 26 4,8 1

39、1,14 002 24 6,5 10,74 004 22 8,5 7,40 006 20 11,5 5,54 010 18 15,0 4,59 012 16 19,5 4,10 020 14 24,0 3,79 030 12 35,0 3,45 050 10 43,0 2,62 090 8 68,0 2,27 140 6 85,0 1,95 220 4 115,0 1,62 340 2 166,0 1,47 530 0 216,0 1,25 EN 2853:20058 Annex A (informative) Supplementary notes A.1 This standard giv

40、es ratings for single cables in free air, which has been taken as the design case for electrical heating. Experimental and practical experience has shown that cables within a bundle benefit from proximity with cables which are lightly loaded intermittently. A.2 No account has been taken in this stan

41、dard or in EN 3197 of the effect of altitude on heat dissipation. The view has been taken that cables which are likely to be electrically loaded to a level approaching their rated temperature would be in the pressurized zones of an aircraft, which does not create any significant altitude de-rating.

42、Cables in unpressurized areas generally experience very low temperatures when at altitude which more than offset any altitude de-rating. A.3 It is accepted that the adoption of a 40 C rise by electrical heating may appear to be slightly cautious. The establishment of this datum recognizes the disadv

43、antage of having “hot cables“ in aircraft in respect of the effect upon the installation, risks to servicing personnel, the reduction of “resistance to failure“ and the adverse effect upon installed life. The limiting effect of voltage drop and the design limitation of associated wiring accessories

44、has been recognized in this standard. A.4 The significance of the rating of cables to the setting of electrical protection levels has been noted. It is, however, now widely appreciated that such protection only has relevance to faults which represent a classic overload. Electrical faults taking the

45、form of high resistance joints or intermittent splashing and arcing between cables or to ground (earth) usually are not identifiable as overloads until the fault is considerably developed. Clearly the adoption of the lowest rating of protection trip level, short of unreliability, is desirable. EN 28

46、53:20059 Annex B (normative) Current rating tests B.1 General As noted in this standard, it may be necessary to establish current rating figures for a cable construction or cable application which differs from the established norms or for certification purposes. This Annex gives a method for establi

47、shing the continuous rating of cable and also short duration “duty cycle” ratings. The shortest duration has been set at 2 s because, in practice, current ratings at shorter periods would be difficult to achieve due to factors such as cable voltage drop and power supply regulation. However, the test

48、 method may be employed for duration of less than 2 s if this is required for purposes such as protection co-ordination. B.2 Test rationale B.2.1 The basic test method requires that a single cable be raised in temperature from a value Tu by a set increment, typically 40 C as in this specification, t

49、o a value Tr, the rated temperature of the cable. The current values given in Table 1 herein were established for a cable with a Tr of 135 C. Therefore Tu in this case is (Tr 40) C = 95 C B.2.2 Determination of cable temperature rise is achieved by monitoring the change in resistance of the test specimen, this being calculated from voltage and current measurements. For larger sizes of cable it may be practical to measure conductor temperature with a thermocouple, placed under the cable insulation tightly against the conductor. It shall