FOREWORD

1 Scope

2 Normative references

3 Terms, definitions, symbols and units

3.1 Terms and definitions

3.2 Symbols and units

4 General

5 Rigid conductor arrangements

5.1 General

5.2 Calculation of electromagnetic forces

5.2.1 Calculation of peak force between the main conductors during a three-phase short-circuit

5.2.2 Calculation of peak force between the main conductors during a line-to-line short-circuit

5.2.3 Calculation of peak value of force between coplanar sub-conductors

5.3 Effective distance between main conductors and between sub-conductors

5.4 Calculation of stresses in rigid conductors

5.4.1 Calculation of stresses

5.4.2 Section modulus and factor q of main conductor composed of sub-conductors

5.4.3 Permitted conductor stress

5.5 Structure loads due to rigid conductors

5.6 Consideration of automatic reclosing

5.7 Calculation with special regard to conductor oscillation

5.7.1 General

5.7.2 Determination of relevant natural frequency

5.7.3 The factors VF, Vσm, Vσs, Vrm and Vrs

6 Flexible conductor arrangements

6.1 General

6.2 Effects on horizontal main conductors

6.2.1 General

6.2.2 Characteristic dimensions and parameter

6.2.3 Tensile force Ft,d during short-circuit caused by swing out (short-circuit tensile force) without dropper in midspan

6.2.4 Dynamic change of sag due to elongation of conductor and change of shape of the conductor curve

6.2.5 Tensile force Ft,d during short-circuit caused by swing out (short-circuit tensile force) with dropper in the middle of the span

6.2.6 Tensile force Ff,d after short-circuit caused by drop (drop force)

6.2.7 Horizontal span displacement bh and minimum air clearance amin

6.3 Effects on vertical main conductors (droppers)

6.4 Effects on bundled conductors

6.4.1 Characteristic dimensions and parameter

6.4.2 Tensile force Fpi,d in the case of clashing sub-conductors

6.4.3 Tensile force Fpi,d in the case of non-clashing sub-conductors

6.5 Structure loads due to flexible conductors

6.5.1 Design load for post insulators, their supports and connectors

6.5.2 Design load for structures, insulators and connectors with tensile forces transmitted by insulator chains

6.5.3 Design load for foundations

7 The thermal effect on bare conductors

7.1 General

7.2 Calculation of thermal equivalent short-circuit current

7.3 Calculation of temperature rise and rated short-time withstand current density for conductors

7.4 Calculation of thermal short-time strength for different durations of the short-circuit

Annex A (normative) Equations for calculation of diagrams

Bibliography

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IEC 60865-1:2011

Gulf StandardGSO IEC 60865-1:2015

GSO IEC 60865-1:2015Gulf Standard

GSO IEC 60865-1:2015

IEC 60865-1:2011

مواصفة قياسية خليجية

تيارات القصر - حساب التأثيرات الجزء 1: التعريفات وطرق الحساب

Gulf Standard

Short-circuit currents - Calculation of effects - Part 1: Definitions and calculation methods

ICS:	17.220.01 ; 29.240.20

English Language – اللغةالإنجليزيةEdition 1 – 03/09/2015 – 1 الطبعة

هذه الوثيقة محمية بالقانون

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P.O.Box: 85245 Riyadh 12511

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Website:

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:موقع ويب

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Gulf StandardGSO IEC 60865-1:2015

GSO IEC 60865-1:2015Gulf Standard

Gulf Foreword

GCC Standardization Organization (GSO) is a regional organization which consists of the national standardization bodies of GCC member states. One of GSO main functions is to issue gulf standards and technical regulations through specialized technical committees.

GSO Technical Council in its meeting number (36) held on 19/11/1436 H, which corresponds to 03/09/2015, has approved Gulf Standard GSO IEC 60865-1:2015 titled "Short-circuit currents - Calculation of effects - Part 1: Definitions and calculation methods" in English language which was studied and adopted by endorsement from International Electrotechnical Commission Standard IEC 60865-1:2011 through fast track .

تقديم خليجي

هيئة التقييس لدول مجلس التعاون لدول الخليج العربية هيئة إقليمية تضم في عضويتها أجهزة التقييس الوطنية في الدول الأعضاء ، ومن مهام الهيئة إعداد المواصفات القياسية واللوائح الفنية الخليجية بواسطة لجان فنية متخصصة.

قرر المجلس الفني لهيئة التقييس لدول مجلس التعاون لدول الخليج العربية في الاجتماع الـ (36) بتاريخ 1436/11/19 هـ ،الموافق 2015/09/03م اعتماد المواصفة القياسية الخليجية رقم GSO IEC 60865-1:2015 وعنوانها "تيارات القصر - حساب التأثيرات الجزء 1: التعريفات وطرق الحساب" باللغة الانجليزية التي تم دراستها وتبنيها بالمصادقة عبر المسار السريع عن اللجنة الدولية الكهروتقنية رقم IEC 60865-1:2011 .

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IEC 60865-1:2011 ED3 © IEC 2011

Gulf StandardGSO IEC 60865-1:2015

GSO IEC 60865-1:2015Gulf Standard

IEC 60865-1

	INTERNATIONAL STANDARD	Edition 3.0 2011-10


	Short-circuit currents – Calculation of effects – Part 1: Definitions and calculation methods

IEC 60865-1:2011 ED3

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Gulf StandardGSO IEC 60865-1:2015

GSO IEC 60865-1:2015Gulf Standard

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or your local IEC member National Committee for further information.

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About the IEC The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes International Standards for all electrical, electronic and related technologies. About IEC publications The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the latest edition, a corrigendum or an amendment might have been published.

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IEC 60865-1:2011 ED3 © IEC 2011

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IEC 60865-1:2011 ED3 © IEC 2011

Gulf StandardGSO IEC 60865-1:2015

GSO IEC 60865-1:2015Gulf Standard

IEC 60865-1

	INTERNATIONAL STANDARD	Edition 3.0 2011-10


	Short-circuit currents – Calculation of effects – Part 1: Definitions and calculation methods

INTERNATIONAL

ELECTROTECHNCIAL

COMMISSION

ICS 17.220.01, 29.240.20ISBN 9782889127719Warning! Make sure that you obtained this publication from an authorized distributor.© Registered trademark of the International Electrotechnical Commission

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IEC 60865-1:2011 ED3 © IEC 2011

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IEC 60865-1:2011 ED3 © IEC 2011

Gulf StandardGSO IEC 60865-1:2015

GSO IEC 60865-1:2015Gulf Standard

CONTENTS

FOREWORD

1 Scope

2 Normative references

3 Terms, definitions, symbols and units

3.1 Terms and definitions

3.2 Symbols and units

4 General

5 Rigid conductor arrangements

5.1 General

5.2 Calculation of electromagnetic forces

5.2.1 Calculation of peak force between the main conductors during a three-phase short-circuit

5.2.2 Calculation of peak force between the main conductors during a line-to-line short-circuit

5.2.3 Calculation of peak value of force between coplanar sub-conductors

5.3 Effective distance between main conductors and between sub-conductors

5.4 Calculation of stresses in rigid conductors

5.4.1 Calculation of stresses

5.4.2 Section modulus and factor q of main conductor composed of sub-conductors

5.4.3 Permitted conductor stress

5.5 Structure loads due to rigid conductors

5.6 Consideration of automatic reclosing

5.7 Calculation with special regard to conductor oscillation

5.7.1 General

5.7.2 Determination of relevant natural frequency

5.7.3 The factors VF, Vσm, Vσs, Vrm and Vrs

6 Flexible conductor arrangements

6.1 General

6.2 Effects on horizontal main conductors

6.2.1 General

6.2.2 Characteristic dimensions and parameter

6.2.3 Tensile force Ft,d during short-circuit caused by swing out (short-circuit tensile force) without dropper in midspan

6.2.4 Dynamic change of sag due to elongation of conductor and change of shape of the conductor curve

6.2.5 Tensile force Ft,d during short-circuit caused by swing out (short-circuit tensile force) with dropper in the middle of the span

6.2.6 Tensile force Ff,d after short-circuit caused by drop (drop force)

6.2.7 Horizontal span displacement bh and minimum air clearance amin

6.3 Effects on vertical main conductors (droppers)

6.4 Effects on bundled conductors

6.4.1 Characteristic dimensions and parameter

6.4.2 Tensile force Fpi,d in the case of clashing sub-conductors

6.4.3 Tensile force Fpi,d in the case of non-clashing sub-conductors

6.5 Structure loads due to flexible conductors

6.5.1 Design load for post insulators, their supports and connectors

6.5.2 Design load for structures, insulators and connectors with tensile forces transmitted by insulator chains

6.5.3 Design load for foundations

7 The thermal effect on bare conductors

7.1 General

7.2 Calculation of thermal equivalent short-circuit current

7.3 Calculation of temperature rise and rated short-time withstand current density for conductors

7.4 Calculation of thermal short-time strength for different durations of the short-circuit

Annex A (normative) Equations for calculation of diagrams

Bibliography

INTERNATIONAL ELECTROTECHNICAL COMMISSION

International StandardIEC 60865-1:2011 ED3

Short-circuit currents - Calculation of effects - Part 1: Definitions and calculation methods

FOREWORD

The International Electrotechnical Commission (IEC) is a 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 other 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 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 determined by agreement between the two organizations.

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 Committees.

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 which they are used or for any misinterpretation by any end user.

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 Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

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 not responsible for any services carried out by independent certification bodies.

All users should ensure that they have the latest edition of this publication.

No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical 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 IEC Publications.

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.

Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60865‑1 has been prepared by IEC technical committee 73: Short-circuit currents.

This third edition cancels and replaces the second edition published in 1993. This edition constitutes a technical revision.

The main changes with respect to the previous edition are listed below:

•

The determinations for automatic reclosure together with rigid conductors have been revised.

•

The influence of mid-span droppers to the span has been included.

•

For vertical cable-connection the displacement and the tensile force onto the lower fixing point may now be calculated.

•

Additional recommendations for foundation loads due to tensile forces have been added.

•

The subclause for determination of the thermal equivalent short-circuits current has been deleted (it is now part of IEC 60909‑0).

•

The regulations for thermal effects of electrical equipment have been deleted.

•

The standard has been reorganized and some of the symbols have been changed to follow the conceptual characteristic of international standards.

The text of this standard is based on the following documents:

CDV	Report on voting
73/152/CDV	73/153/RVC

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 list of all parts of the IEC 60865 series, under the general title, Short-circuit currents – Calculation of effects can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC web site 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.

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Gulf StandardGSO IEC 60865-1:2015

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International StandardIEC 60865-1:2011 ED3

Short-circuit currents - Calculation of effects - Part 1: Definitions and calculation methods

1Scope

This part of IEC 60865 is applicable to the mechanical and thermal effects of short-circuit currents. It contains procedures for the calculation of

–

the electromagnetic effect on rigid conductors and flexible conductors,

–

the thermal effect on bare conductors.

For cables and insulated conductors, reference is made, for example, to IEC 60949 and IEC 60986. For the electromagnetic and thermal effects in d.c. auxiliary installations of power plants and substations reference is made to IEC 61660‑2.

Only a.c. systems are dealt with in this standard.

The following points should, in particular, be noted:

The calculation of short-circuit currents should be based on IEC 60909. For the determination of the greatest possible short-circuit current, additional information from other IEC standards may be referred to, e.g. details about the underlying circuitry of the calculation or details about current-limiting devices, if this leads to a reduction of the mechanical stress.

Short-circuit duration used in this standard depends on the protection concept and should be considered in that sense.

These standardized procedures are adjusted to practical requirements and contain simplifications which are conservative. Testing or more detailed methods of calculation or both may be used.

In Clause 5 of this standard, for arrangements with rigid conductors, only the stresses caused by short-circuit currents are calculated. Furthermore, other stresses can exist, e.g. caused by dead-load, wind, ice, operating forces or earthquakes. The combination of these loads with the short-circuit loading should be part of an agreement and/or be given by standards, e.g. erection-codes.

The tensile forces in arrangements with flexible conductors include the effects of dead-load. With respect to the combination of other loads the considerations given above are valid.

The calculated loads are design loads and should be used as exceptional loads without any additional partial safety factor according to installation codes of, for example, IEC 61936‑1 [1]1.

2Normative 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.

IEC 60909 (all parts), Short-circuit current calculation in three-phase a.c. systems

IEC 60909‑0, Short-circuit currents in three-phase a.c. systems – Part 0: Calculation of currents

IEC 60949, Calculation of thermally permissible short-circuit currents, taking into account non-adiabatic heating effects

IEC 60986, Short-circuit temperature limits of electric cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)

IEC 61660‑2, Short-circuit currents in d.c. auxiliary installations in power plants and substations – Part 2: Calculation of effects

3.1Terms and definitions

For the purposes of this document the following terms and definitions apply.

3.1.1

main conductor

conductor or arrangement composed of a number of conductors which carries the total current in one phase

3.1.2

sub-conductor

single conductor which carries a certain part of the total current in one phase and is a part of the main conductor

3.1.3

fixed support

support of a rigid conductor in which moments are imposed in the regarded plane

3.1.4

simple support

support of a rigid conductor in which no moments are imposed in the regarded plane

3.1.5

connecting piece

any additional mass within a span which does not belong to the uniform conductor material, includingamong others, spacers, stiffening elements, bar overlappings, branchings, etc.

3.1.6

spacer

mechanical element between sub-conductors, rigid or flexible, which, at the point of installation, maintains the clearance between sub-conductors

3.1.7

stiffening element

special spacer intended to reduce the mechanical stress of rigid conductors

3.1.8

relevant natural frequency

fcm

first natural frequency of the free vibration of a single span beam without damping and natural frequency of order ν of beams with ν spans without damping

3.1.9

short-circuit tensile force

Ft,d

maximum tensile force (design value) in a flexible main conductor due to swing out reached during the short-circuit

3.1.10

drop force

Ff,d

maximum tensile force (design value) in a flexible main conductor which occurs when the span drops down after swing out

3.1.11

pinch force

Fpi,d

maximum tensile force (design value) in a bundled flexible conductor during the short-circuit due to the attraction of the sub-conductors in the bundle

3.1.12

duration of the first short-circuit current flow

Tk1

time interval between the initiation of the short-circuit and the first breaking of the current

3.1.13

thermal equivalent short-circuit current

Ith

r.m.s. value of current having the same thermal effect and the same duration as the actual short-circuit current, which can contain d.c. component and can subside in time

3.1.14

thermal equivalent short-circuit current density

Sth

ratio of the thermal equivalent short-circuit current and the cross-section area of the conductor

3.1.15

rated short-time withstand current density, Sthr, for conductors

r.m.s. value of the current density which a conductor is able to withstand for the rated short time

3.1.16

duration of short-circuit current

sum of the time durations of the short-circuit current flow from the initiation of the first short-circuit to the final breaking of the current in all phases

3.1.17

rated short-time

Tkr

time duration for which a conductor can withstand a current density equal to its rated short-time withstand current density

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Bibliography

[1]		IEC 61936‑1, Power installations exceeding 1 kV a.c. – Part 1: Common rules
[2]		CIGRE, The mechanical effects of short-circuit currents in open air substations (Rigid and flexible conductors). Vol. 105. Paris: CIGRÉ SC 23, WG 11, 1996.
[3]		CIGRE, The mechanical effects of short-circuit currents in open air substations (Part II). Vol. 214. Paris: CIGRÉ SC 23, WG 03, 2002.

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1Figures in square brackets refer to the bibliography.