1、BRITISH STANDARD AEROSPACE SERIES BS EN 3841-404:2004 Circuit breakers Test methods Part 404: Explosion Proofness The European Standard EN 3841-404:2004 has the status of a British Standard ICS 49.060 BS EN 3841-404:2004 This British Standard was published under the authority of the Standards Policy
2、 and Strategy Committee on 21 February 2005 BSI 21 February 2005 ISBN 0 580 45534 3 National foreword This British Standard is the official English language version of EN 3841-404:2004. The UK participation in its preparation was entrusted by Technical Committee ACE/6, Aerospace avionic electrical a
3、nd fibre optic technology, to Subcommittee ACE/6/5, Circuit breakers, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications r
4、eferred 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 Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary pr
5、ovisions 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 to understand the text; present to the responsible international/European committee any enquiries on the interpretati
6、on, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 6, an inside back cover and a back cove
7、r. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN3841404 December2004 ICS49.060 Englishversion AerospaceseriesCircuitbreakersTestmethodsPart40
8、4: Explosionproofness SriearospatialeDisjoncteursMthodesdessais Partie404:Antidflagration LuftundRaumfahrtSchutzschalterPrfverfahrenTeil 404:Explosionsdichtheit ThisEuropeanStandardwasapprovedbyCENon10September2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatethecond
9、itionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).
10、Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hun
11、gary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 200
12、4CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN3841404:2004:E EN 3841-404:2004 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Method 4 3.1 Test mounting 4 3.2 Procedure .6 3.3 Requirement.6 EN 3841-404:2004 (E) 3 Foreword This
13、document (EN 3841-404:2004) 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 received the approval of the National Associations and the Of
14、ficial 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 June 2005, and conflicting national standards shall be withdrawn
15、 at the latest by June 2005. 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, Icelan
16、d, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 3841-404:2004 (E) 4 1 Scope This standard specifies a method of verifying explosion proofness of circuit breakers. It shall be used to
17、gether with EN 3841-100. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. I
18、SO 7137, Aircraft Environmental conditions and test procedures for airborne equipment EN 3841-100, Aerospace series Circuit breakers Test methods Part 100: General 3 Method 3.1 Test mounting 3.1.1 General The circuit breakers shall be mounted approximately in the centre of the chamber, and as specif
19、ied in EN 3841-100, in connection with the applicable product standard. The chamber volume ( 25 l) shall ensure that the circuit breakers are evenly exposed to the explosive mixture. The test chamber shall be fitted with a spark plug which allows the combustibility of the mixture to be verified when
20、 the chamber is closed. The test chamber shall provide a facility to switch on the circuit breakers when the chamber is closed (for manual or remote operation). 3.1.2 Test circuit According to Figure 1 with d.c. and a.c., single-pole. According to Figure 2 with a.c., three-pole. EN 3841-404:2004 (E)
21、 5 U k: test chamber (for explosion proofness) L1, L2, L3 : a.c. phases N : neutral W or M : converter or shunt for current measurement P1 : test specimen (circuit breaker) U g: voltage at circuit breakers terminals Key 1 d.c.; a.c. Figure 1 Key 1 d.c.; a.c. Figure 2 Where S1 : main switch L : induc
22、tance R : loading resistor EN 3841-404:2004 (E) 6 3.1.3 Test mixture Gas mixture of air and fuel vapour (grade of fuel 100/130 octane gasoline or propane or standard hexane, with a volumetric ratio of 13:1) following ISO 7137. 3.1.4 Test temperature The test temperature shall be 70 C. 3.1.5 Pressure
23、 in the test chamber The pressure in the test chamber shall be atmospheric pressure at normal altitude. 3.2 Procedure The test chamber shall be heated to the temperature and filled with the explosive mixture. (the explosive mixture may also be produced by injecting the fuel quantity proportionate to
24、 the chamber volume, provided that an adequate mixing and even distribution of the mixture are ensured). The circuit breakers shall be stored in the explosive atmosphere for 3 h prior to break operations. The operations as outlined in the product standard shall be carried out at intervals of 1 h. Th
25、e mixture shall remain explosive during this period. 3.3 Requirement The explosive mixture shall not ignite when the circuit breakers are operated. On completion of the operations, combustibility of the mixture shall be verified by means of the spark plug. If the mixture does not ignite, the test sh
26、all be repeated with new test samples. blankBS EN 3841-404:2004 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level.
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