BS EN 60721-3-0-1991 Classification of environmental conditions - Classification of groups of environmental parameters and their severities - Introduction《环境条件分类 环境参数组及其影响的分类 介绍》.pdf

《BS EN 60721-3-0-1991 Classification of environmental conditions - Classification of groups of environmental parameters and their severities - Introduction《环境条件分类 环境参数组及其影响的分类 介绍》.pdf》由会员分享，可在线阅读，更多相关《BS EN 60721-3-0-1991 Classification of environmental conditions - Classification of groups of environmental parameters and their severities - Introduction《环境条件分类 环境参数组及其影响的分类 介绍》.pdf（18页珍藏版）》请在麦多课文档分享上搜索。

1、BRITISH STANDARD BS EN 60721-3-0:1993 IEC721-3-0: 1984 (Incorporating Amendment No.1 and Corrigendum December1985) Classification of environmental conditions Part3: Classification of groups of environmental parameters and their severities Section3.0 Introduction The European Standard EN60721-3-0:199

2、3 has the status of a BritishStandard UDC 621.3:620.193BSEN60721-3-0:1993 This British Standard, having been prepared under the directionof the General Electrotechnical Standards PolicyCommittee, was publishedunder the authority ofthe Standards Board and comes into effect on 29 November1991 BSI 04-2

3、000 The following BSI references relate to the work on this standard: Committee reference GEL/15 Special announcement in BSINews July1991 ISBN 0 580 20163 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the General Electrotechnical Standar

4、ds Policy Committee(GEL/-) to Technical Committee GEL/15, upon which the following bodies were represented: Directorate of Telecommunications EEA(the Association of Electronics, Telecommunications and Business Equipment Industries) Electronic Components Industry Federation Ministry of Defence Nation

5、al Supervising Inspectorate Society of Environmental Engineers Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No. Date Comments 8009 October 1993 Indicated by a sideline in the marginBSEN60721-3-0:1993 BSI 04-2000 i Contents Page Committees responsible In

6、side front cover National foreword ii Foreword 2 Text of EN60721-3-0 3 Publication(s) referred to Inside back coverBSEN60721-3-0:1993 ii BSI 04-2000 National foreword This Section of BS7527 has been prepared under the direction of the General Electrotechnical Standards Policy Committee. It is identi

7、cal with IECPublication721-3-0:1984 “Classification of environmental conditions Part3:Classification of groups of environmental parameters and their severities. Introduction” as amended by Amendment No.1(1987) and Corrigendum December1985, published by the International Electrotechnical Commission(I

8、EC). In1993 the European Committee for Electrotechnical Standardization (CENELEC) accepted IEC721-3-0:1984 together with Amendment1:1987 as European Standard EN60721-3-0:1993. As a consequence of implementing the European Standard this BritishStandard is renumbered as BS EN60721-3-0 and any referenc

9、e to BS7527-3.0 should be read as a reference to BSEN60721-3-0. The changes added by Amendment No.1(1987) and the Corrigendum are indicated by a sideline in the margin. This Section of BS7527 implements CENELEC Harmonization Document(HD)478.3.0 S2. Other Parts of this BritishStandard are as follows.

10、 Part1: Environmental parameters and their severities; Part2: Environmental conditions appearing in nature; Section2.1: Temperature and humidity; Section2.2: Precipitation and wind; Section2.3: Air pressure; Section2.4: Solar radiation and temperature; Section2.5: Dust, sand, salt mist; Section2.6:

11、Earthquake vibration and shock; Section2.7: Fauna and flora; Part3: Classification of groups of environmental parameters and their severities; Section3.1: Storage; Section3.2: Transportation; Section3.3: Stationary use at weatherprotected locations; Section3.4: Stationary use at non-weatherprotected

12、 locations; Section3.5: Ground vehicle installations; Section3.6: Ship environment; Section3.7: Portable and non-stationary use. Cross-references International Standard Corresponding BritishStandard IEC68 BS2011 Environmental testing (Most Parts identical) BS7527 Classification of environmental cond

13、itions IEC721-1:1990 Part1:1991 Environmental parameters and their severities (Identical)BSEN60721-3-0:1993 BSI 04-2000 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance

14、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 to iv, theENtitle page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) an

15、d may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN60721-3-0 July1993 UDC 621.3:620.193 Supersedes HD478.3.0 S2:1989 Descriptors: Environmental parameter English version Classific

16、ation of environmental conditions Part3: Classification of groups of environmental parameters and their severities Introduction (IEC721-3-0:1984+A1:1987) Classification des conditions denvironnement Troisime partie: Classification des groupements des agents denvironnement et de leurs svrits Introduc

17、tion (CEI721-3-0:1984+A1:1987) Klassifizierung von Umweltbedingungen Teil3: Klassen von Umwelteinflugren und deren Granzwerte Einfhrung und Hinweise fr den Anwender (IEC721-3-0:1984+A1:1987) This European Standard was approved by CENELEC on1993-07-06. CENELEC members are bound to comply with the CEN

18、/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 bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to

19、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 responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official ve

20、rsions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical Stand

21、ardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1993 Copyright reserved to CENELEC members Ref.No.EN60721-3-0:1993EEN60721-3-0:1993 BSI 04-2000 2 Foreword At the request of the72nd Te

22、chnical Board HD478.3.0 S2:1989(IEC721-3-0:1984+A1:1987) was submitted to the CENELEC voting procedure for conversion into a European Standard. The text of the International Standard was approved by CENELEC as EN60721-3-0 on6July1993. The following dates were fixed: Annexes designated “normative” ar

23、e part of the body of the standard. In this standard, Annex ZA is normative. Contents Page Foreword 2 1 Scope 3 2 Object 3 3 Content and layout 3 4 Background information for the selection of environmental parameters and severities for the classes 3 5 Guidance for the use of IEC Publication721-3 4 6

24、 Duration and frequency of occurrence 6 Appendix A Examples of application 8 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications 9 Figure 1 Illustration of the fraction of time orfraction of the total number of event

25、s when acertain environmental severity is exceeded 4 Table I Total duration of application 7 Table II Maximum duration of single occurrence 7 Table III Frequency of occurrence 7 latest date of publication ofan identical national standard (dop) 1994-03-01 latest date of withdrawal ofconflicting natio

26、nal standards (dow) EN60721-3-0:1993 BSI 04-2000 3 1 Scope IEC Publication721-3: Classification of Environmental Conditions, Part3: Classification of Groups of Environmental Parameters and Their Severities, establishes classes of environmental parameters and their severities, covering the extreme(sh

27、ort-term) conditions which may be met by a product when being transported, installed, stored and used. Separate groups of classes are given for different product applications (e.g.weather-protected stationary, mounted in ground vehicles, transportation). The classes also take into account the degree

28、 of restriction of the use of the product from very restricted conditions (e.g.in temperature-controlled rooms) to unrestricted conditions. The classification covers natural as well as man-made conditions. 2 Object This Introduction is a guide for the use of all parts of IEC Publication721-3. It con

29、tains background information including information on application and limitation of the classes given in various parts of IEC Publication721-3. It describes the difference between the environmental conditions the product will meet during its life, described by the classes in IEC Publication721-3, an

30、d conditions of test used to assure that the product will work satisfactorily under such environmental conditions. The use of IEC Publication721-3 in the design, limitation of conditions and protection is also included. Thedifferences are explained between extreme environmental conditions with a sma

31、ll probability of being exceeded, normally approached only for short periods, and more long-lasting normal environmental conditions. This Introduction also gives guidance for applying factors of duration and frequency of occurrence in characterizing the contribution of a significant parameter of a c

32、lass. Reference to IEC Publication721-3-0 is strongly recommended in order to avoid misuse of the classes defined in the other parts of IEC Publication721-3. 3 Content and layout Separate groups of classes of environmental conditions are given for the following product applications: The classes are

33、identified by: a digit defining the application(1 for storage,2 for transportation, 3 for stationary use, etc.); a letter for climatic conditions(K), biological conditions(B), chemically active substances (C), mechanically active substances(S) or mechanical conditions(M). To be extended if necessary

34、; a further digit indicating severity, where a higher digit normally indicates more stringent conditions. A class may be further divided into H(High) or L(Low) to allow for conditions where, for example, the temperature may be severely low but never high. The parts of IEC Publication721-3 contain ta

35、bles giving all classes, including the severity of each environmental parameter for each class. In addition, every publication includes an appendix giving details of conditions which products are assumed to meet and which form a basis for the classes. These appendices are intended to guide the user

36、of the publication in his selection of the class appropriate to his special product application. 4 Background information for the selection of environmental parameters and severities for the classes The environmental parameters listed for a class are the conditions covered by the class to which a pr

37、oduct will be subjected. They are selected by using the complete set of environmental parameters in IEC Publication721-1: Classification of Environmental Conditions, Part I: Classification of Environmental Parameters and Their Severities, as a “check list”. The severities given for each environmenta

38、l parameter are those which are exceeded either for an insignificant part of the continuous exposure time(e.g.temperature conditions), or for an insignificant fraction of the total number of events(e.g.shocks). Thus the classes given in IECPublication721-3 can be used for defining themaximum short-t

39、erm environmental stresses of a product, but do not give any information on the long-term, or total life duration of the product environmental stresses. This is illustrated in Figure 1, page 4. Publications 721-3-1: Storage; 721-3-2: Transportation; 721-3-3: Stationary Use, Weather-protected; 721-3-

40、4: Stationary Use, Non-weatherprotected; 721-3-5: Ground Vehicle Installations; 721-3-6: Ship Environment; 721-3-7: Portable and Non-stationary Use. Example: Class2K3, where: 2 = transportation; K = climatic conditions; 3 = severity.EN60721-3-0:1993 4 BSI 04-2000 The severities given in the classifi

41、cation are represented by one value x 1 , whilst the information needed for defining the totality of environmental stresses during the lifetime of a product includes the total curve, P(x x 0 ) for all values of x 0 . Although available data do not make it possible to give an exact figure on the prob

42、ability level used in the classification, P(x x 1 ) is usually considerably less than0.01. A product will be simultaneously exposed to a large number of environmental parameters. Some of the parameters are statistically dependent, for example, low air velocity and low temperature, sun radiation and

43、high temperature. Other parameters are statistically independent, for example vibration and temperature(normally). The probability of simultaneous exposure to extreme severities of independent environmental parameters x and y is equal to the product of the probabilities of exposure to each of the pa

44、rameters, i.e.: P(x, y x 1 , y 1 )=P(x x 1 ) P(y y 1 ) Example: If the probability of exceeding each of the parameters P(x x 1 )=P(y y 1 )=0.01, then P(x, y x 1 , y 1 )=0.0001 It should be noted that in many cases the product is exposed for only limited periods to the environment from which the stat

45、istical data have been collected. In such cases severities in the classification have been selected which have a probability higher than0.01 of being exceeded. Consequently, the probability of the combination of the product being exposed to the environment and of the class limit severity is reasonab

46、le(in the order of magnitude of0.01). 5 Guidance for the use of IECPublication721-3 5.1 General All products have to be designed to survive and work in more or less severe environments. Basically they will be affected by the environmental influences in two ways: by the effects of short-term extreme

47、environmental conditions, which may directly cause malfunction or destroy the product; by the effect of long-term subjection to non-extreme environmental stresses, which may slowly degrade the product and finally cause malfunction or destruction of the product. The short-term extreme environmental c

48、onditions, defined in IEC Publication721-3, may occur at any time in the products life. A product may be unaffected by an extreme condition when it is new but fail when it is subjected to the same condition after being used for a long period due to the effect of ageing. Figure 1 Illustration of the

49、fraction of time or fraction of the total number of events whenacertain environmental severity is exceededEN60721-3-0:1993 BSI 04-2000 5 Extreme conditions may affect the product: only when the product is non-operating(e.g.during storage and transportation), only when the product is operating, or both. It is therefore important for the product specification, when referring to a certain class in IEC Publication721-3, to define whether the product is required to be capable of operating or onl