1、Electric cables Calculation of the current rating Part 3-1: Operating conditions - Site reference conditionsBS IEC 60287-3-1:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06IEC 60287-3-1Edition 2.0 2017-06 INTERNATIONAL STANDARD NORME INTERNATIONALE Electric cabl
2、es Calculation of the current rating Part 3-1: Operating conditions Site reference conditions Cbles lectriques Calcul du courant admissible Partie 3-1: Conditions de fonctionnement Conditions du site de rfrence INTERNATIONAL ELECTROTECHNICAL COMMISSIONCOMMISSIONELECTROTECHNIQUEINTERNATIONALE ICS 29.
3、060.20 ISBN 978-2-8322-4348-0 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warning! Make sure that you obtained this publication from an authorized distributor.Attention! Veuillez vous assurer que vous avez obtenu
4、 cette publication via un distributeur agr.National forewordThis British Standard is the UK implementation of IEC 60287-3-1:2017. It supersedes BS 7769-3.1:1997 (dual numbered as IEC 60287-3-1:1995), which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee GEL/
5、20/16, Electric Cables - Medium/high voltage.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Stand
6、ards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 84671 7ICS 29.060.20Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2017.Amen
7、dments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS IEC 6028731:2017IEC 60287-3-1 Edition 2.0 2017-06 INTERNATIONAL STANDARD NORME INTERNATIONALE Electric cables Calculation of the current rating Part 3-1: Operating conditions Site reference conditions Cbles lectriques Cal
8、cul du courant admissible Partie 3-1: Conditions de fonctionnement Conditions du site de rfrence INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE ICS 29.060.20 ISBN 978-2-8322-4348-0 Registered trademark of the International Electrotechnical Commission Marque dpos
9、e de la Commission Electrotechnique Internationale Warning! Make sure that you obtained this publication from an authorized distributor. Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agr. BS IEC 6028731:2017 2 IEC 60287-3-1:2017 IEC 2017 CONTENTS FOREWOR
10、D . 3 INTRODUCTION . 5 1 Scope 6 2 Normative references 6 3 Terms and definitions 6 4 Reference ambient temperatures and thermal resistivities of soil in various countries . 6 4.1 Operating conditions Site reference conditions 6 4.2 Procedure when values are not provided in national tables . 7 4.2.1
11、 General . 7 4.2.2 Ambient temperatures at sea level . 7 4.2.3 Thermal resistivity of soil . 7 4.2.4 Solar radiation . 7 Annex A (informative) Values relating to the operating conditions in various countries . 8 A.1 Australia . 8 A.2 Austria 8 A.3 Canada . 9 A.4 China 10 A.5 Egypt 10 A.6 Finland . 1
12、1 A.7 France 12 A.8 Germany . 13 A.9 Italy 14 A.10 Japan 14 A.11 Mexico 14 A.12 Netherlands 17 A.13 New Zealand . 18 A.14 Norway . 18 A.15 Oman 19 A.16 Poland 19 A.17 Portugal 20 A.18 Spain 20 A.19 South Africa 21 A.20 Sweden . 21 A.21 Switzerland . 22 A.22 United Kingdom 22 A.22.1 HV . 22 A.22.2 LV
13、/MV . 23 A.23 United States of America 23 Bibliography 24 Table 1 Ambient temperatures at sea level 7 Table 2 Thermal resistivity of soil . 7 BS IEC 6028731:2017 2 IEC 60287-3-1:2017 IEC 2017 CONTENTS FOREWORD . 3 INTRODUCTION . 5 1 Scope 6 2 Normative references 6 3 Terms and definitions 6 4 Refere
14、nce ambient temperatures and thermal resistivities of soil in various countries . 6 4.1 Operating conditions Site reference conditions 6 4.2 Procedure when values are not provided in national tables . 7 4.2.1 General . 7 4.2.2 Ambient temperatures at sea level . 7 4.2.3 Thermal resistivity of soil .
15、 7 4.2.4 Solar radiation . 7 Annex A (informative) Values relating to the operating conditions in various countries . 8 A.1 Australia . 8 A.2 Austria 8 A.3 Canada . 9 A.4 China 10 A.5 Egypt 10 A.6 Finland . 11 A.7 France 12 A.8 Germany . 13 A.9 Italy 14 A.10 Japan 14 A.11 Mexico 14 A.12 Netherlands
16、17 A.13 New Zealand . 18 A.14 Norway . 18 A.15 Oman 19 A.16 Poland 19 A.17 Portugal 20 A.18 Spain 20 A.19 South Africa 21 A.20 Sweden . 21 A.21 Switzerland . 22 A.22 United Kingdom 22 A.22.1 HV . 22 A.22.2 LV/MV . 23 A.23 United States of America 23 Bibliography 24 Table 1 Ambient temperatures at se
17、a level 7 Table 2 Thermal resistivity of soil . 7 IEC 60287-3-1:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTRIC CABLES CALCULATION OF THE CURRENT RATING Part 3-1: Operating conditions Site reference conditions FOREWORD 1) The International Electrotechnical Commission (IEC) is a
18、worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to oth
19、er activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the
20、subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions
21、 determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National
22、Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in
23、which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publ
24、ication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is
25、 not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its tec
26、hnical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IE
27、C Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subj
28、ect of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 60287-3-1 has been prepared by IEC technical committee 20: Electric cables. This second edition cancels and replaces the first edition published in 1995 and Amendment 1:1
29、999. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the updated list of national laying conditions is now covered in Annex A; b) Clause 5 about the information required from the purchaser for t
30、he selection of the appropriate type of cable has been removed. BS IEC 6028731:2017 4 IEC 60287-3-1:2017 IEC 2017 The text of this standard is based on the following documents: FDIS Report on voting 20/1714/FDIS 20/1730/RVD Full information on the voting for the approval of this standard can be foun
31、d in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 60287 series, published under the general title Electric cables Calculation of the current rating, can be found on the IEC websi
32、te. The readers attention is drawn to the fact that Annex A lists all of the “in-some-country” clauses on differing practices of a less permanent nature relating to the subject of this standard. The committee has decided that the contents of this publication will remain unchanged until the stability
33、 date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. BS IEC 6028731:2017 4 IEC 60287-3-1:2017 IEC 2017 The text of this standard is ba
34、sed on the following documents: FDIS Report on voting 20/1714/FDIS 20/1730/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A li
35、st of all parts in the IEC 60287 series, published under the general title Electric cables Calculation of the current rating, can be found on the IEC website. The readers attention is drawn to the fact that Annex A lists all of the “in-some-country” clauses on differing practices of a less permanent
36、 nature relating to the subject of this standard. The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication w
37、ill be reconfirmed, withdrawn, replaced by a revised edition, or amended. IEC 60287-3-1:2017 IEC 2017 5 INTRODUCTION IEC 60287 has been divided into three parts so that revisions of, and additions to the document can be carried out more conveniently. Each part is subdivided into subparts which are p
38、ublished as separate standards. Part 1: Formulae for ratings (100 % load factor) and power losses Part 2: Formulae for thermal resistance Part 3: Operating conditions This part of IEC 60287-3 contains reference ambient temperatures and thermal resistivities of soil in various countries. Quantities r
39、elated to the operating conditions of cables are liable to vary considerably from one country to another. For instance, with respect to the ambient temperature and soil thermal resistivity, the values are governed in various countries by different considerations. Superficial comparisons between the
40、values used in the various countries may lead to erroneous conclusions if they are not based on common criteria: for example, there may be different expectations for the life of the cables, and in some countries design is based on maximum values of soil thermal resistivity, whereas in others average
41、 values are used. Particularly, in the case of soil thermal resistivity, it is well known that this quantity is very sensitive to soil moisture content and may vary significantly with time, depending on the soil type, the topographical and meteorological conditions, and the cable loading. The follow
42、ing procedure for choosing the values for the various parameters should, therefore, be adopted. Numerical values should preferably be based on results of suitable measurements. Often such results are already included in national specifications as recommended values, so that the calculation may be ba
43、sed on these values generally used in the country in question; a survey of such values is given in this part of IEC 60287-3. BS IEC 6028731:2017 6 IEC 60287-3-1:2017 IEC 2017 ELECTRIC CABLES CALCULATION OF THE CURRENT RATING Part 3-1: Operating conditions Site reference conditions 1 Scope This part
44、of IEC 60287-3 is applicable to the conditions of steady-state operation of cables at all voltages, buried directly in the ground, in ducts, troughs or in steel pipes, both with and without partial drying-out of the soil, as well as cables in air. The term “steady state“ is intended to mean a contin
45、uous constant current (100 % load factor) just sufficient to produce asymptotically the maximum conductor temperature, the surrounding ambient conditions being assumed constant. This document defines site reference conditions, however the general values are superseded by specific national requiremen
46、ts. 2 Normative references There are no normative references in this document. 3 Terms and definitions No terms and definitions are listed in this document. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/www.e
47、lectropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp 4 Reference ambient temperatures and thermal resistivities of soil in various countries 4.1 Operating conditions Site reference conditions In order to use the formulae given in the various parts of IEC 60287, numerical
48、 values for the physical quantities should be chosen relating to the operating conditions. It is obviously possible to compare the results of two calculations of current rating only when the assumptions made and the numerical values of the parameters are known. In particular, the quantities related
49、to the operating conditions of cables are likely to vary considerably from one country to another. An enquiry into this subject has been carried out and a number of countries have replied. Annex A summarizes the operating conditions used in various countries. Attention is drawn to the fact that the information in Annex A is intended only as a guide for cable installation designers when data provided by a user is incomplete. Care
