1、 IEC/TR 60943Edition 2.1 2009-03TECHNICAL REPORT RAPPORT TECHNIQUEGuidance concerning the permissible temperature rise for parts of electrical equipment, in particular for terminals Guide concernant lchauffement admissible des parties des matriels lectriques, en particulier les bornes de raccordemen
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17、ational Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IEC/TR 60943Edition 2.1 2009-03TECHNICAL REPORT RAPPORT TECHNIQUEGuidance concerning the permissible temperature rise for parts of electrical e
18、quipment, in particular for terminals Guide concernant lchauffement admissible des parties des matriels lectriques, en particulier les bornes de raccordement INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE CKICS 29.020 PRICE CODECODE PRIXISBN 2-8318-1029-8 Regist
19、ered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
20、2 60943 IEC:1998+A1:2008 CONTENTS FOREWORD 4 INTRODUCTION6 Section 1: General 1 General8 1.1 Scope and object8 1.2 Reference documents 8 1.3 Definitions.9 1.4 Symbols 9 Section 2: Theory 2 General considerations concerning the nature of electric contact and the calculation and measurement of the ohm
21、ic resistance of contacts10 2.1 Electric contacts and connection terminals 10 2.2 Nature of electric contact10 2.3 Calculation of contact resistance12 3 Ageing mechanisms of contacts and connection terminals 16 3.1 General.16 3.2 Contacts of dissimilar metals17 3.3 Oxidation ageing mechanisms .19 3.
22、4 Results concerning ageing of copper contacts.21 3.5 Usage and precautions to be taken in the use of contact materials.24 4 Calculation of temperature rise of conductors, contacts and connection terminals 25 4.1 Symbolic representations .25 4.2 Temperature rise Tsof a conductor with respect to the
23、temperature Te of the surrounding medium.27 4.3 Temperature rise To o in the vicinity of the contact: temperature rise of connection terminals.28 4.4 Temperature rise of the elementary contact points 28 Section 3: Application 5 Permissible temperature and temperature rise values29 5.1 Ambient air te
24、mperature a.29 5.2 Temperature and temperature rise of various equipment components .30 5.3 Temperature and temperature rise of conductors connecting electrical equipment 38 5.4 Temperature and temperature rise of connection terminals for electrical equipment Influence on connected conductors39 Copy
25、right International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-60943 IEC:1998+A1:2008 3 6 General procedure to be followed for determining permissible temperature and temperature rise .40 6.1 Ba
26、sic parameters40 6.2 Method to be followed for determining maximum permissible temperature and temperature rise 40 Annex A Numerical examples of the application of the theory and other data .42 Annex B Physical characteristics of selected metals and alloys. 45 Annex C Physical characteristics of flu
27、id dielectrics . 46 Annex D nformation on the reaction of contact metals with substances in the atmosphere 47 Annex E Temperature rise of a conductor cooled by radiation and convection in the vicinity of a terminal. 48 Annex F List of symbols used in this report 57 Annex G Bibliography . 59 Copyrigh
28、t International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- 4 60943 IEC:1998+A1:2008 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ GUIDANCE CONCERNING THE PERMISSIBLE TEMPERATURE RISE FOR PARTS OF
29、 ELECTRICAL EQUIPMENT, IN PARTICULAR FOR TERMINALS 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 international co-opera
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36、sible for identifying any or all such patent rights. 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: type 1, when the required support
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39、national 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 60943, which is a technical report of type 3, has been prepared by IEC technical committee 32: Fuses. Copyright International Electro
40、technical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-60943 IEC:1998+A1:2008 5 This consolidated version of IEC 60943 consists of the second edition (1998) documents 32/142/CDV and 32/148/RVC and its amendment 1
41、(2008) documents 32/187/DTR and 32/188/RVC. The technical content is therefore identical to the base edition and its amendment and has been prepared for user convenience. It bears the edition number 2.1. A vertical line in the margin shows where the base publication has been modified by amendment 1.
42、 Annexes are for information only. The committee has decided that the contents of the base publication and its amendments will remain unchanged until the maintenance result date indicated on the IEC web site under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date,
43、 the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- 6 60943 IEC:1998+A1:2008 INTRODUCT
44、ION a) The temperature rise encountered in electrical assemblies as a result of the various losses in the conductors, contacts, magnetic circuits, etc. is of growing importance as a result of the development of new techniques of construction and operation of equipment. This development has been part
45、icularly significant in the field of assemblies, where numerous components dissipating energy (contactors, fuses, resistors, etc.), in particular modular devices are found within enclosures of synthetic materials which are somewhat impermeable to heat. This temperature rise results in a relatively h
46、igh temperature of the basic elements constituting the electric contacts: a high temperature favours oxidation at the contact interface, increases its resistance and thereby leads to further heating, and thus to an even higher temperature. If the component material of the contact is unsuitable or in
47、sufficiently protected, the contact may be irreparably damaged before the calculated useful life of the equipment has expired. Such temperature rises also affect connection terminals and the connected conductors, and their effects should be limited in order to ensure that the insulation of the condu
48、ctors remains satisfactory throughout the life of the installation. b) In view of these problems, this report has been prepared with the following objectives: to analyze the various heating and oxidation phenomena to which the contacts, the connection terminals and the conductors leading to them are subjected, depending on their environment and their arrangement; to provide elementary rules to product committees to enable them to specify permissible temperatures and temperature rises. c) Attention is drawn to the precauti