EN 60383-2:1995

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Insulators for overhead lines with a nominal voltage above 1000 V - Part 2: Insulator strings and insulator sets for a.c. systems - Definitions, test methods and acceptance criteria (IEC 383- 2:1993)Isolatoren für Freileitungen mit einer Nennspannung über 1 kV -- Teil 2: Isolatorstränge und Isolatorketten für Wechselstromsysteme - Begriffe, Prüfverfahren und AnnahmekriterienIsolateurs pour lignes aériennes de tension nominale supérieure à 1 kV -- Partie 2: Chaînes d'isolateurs et chaînes d'isolateurs équipées pour systèmes à courant alternatif - Définitions, méthodes d'essai et critères d'acceptationInsulators for overhead lines with a nominal voltage above 1 kV -- Part 2: Insulator strings and insulator sets for a.c. systems - Definitions, test methods and acceptance criteria29.240.20DaljnovodiPower transmission and distribution lines29.080.10IzolatorjiInsulators01.040.29Elektrotehnika (Slovarji)Electrical engineering (Vocabularies)ICS:Ta slovenski standard je istoveten z:EN 60383-2:1995SIST EN 60383-2:1997en01-november-1997SIST EN 60383-2:1997SLOVENSKI
STANDARD
Insulators for overhead lines with a nominal voltage above 1 000 V – Part 2:
Insulator strings and insulator sets for a.c. systems – Definitions, test methods and acceptance criteria
For price, see current catalogue IEC 1993 Copyright - all rights reserved 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 the publisher. International Electrotechnical Commission,
3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch
Web: www.iec.ch INTERNATIONAL STANDARD IEC60383-2 First edition1993-04 L Commission Electrotechnique InternationaleInternational Electrotechnical CommissionPRICE CODE SIST EN 60383-2:1997

383-2 © I EC:1993– 3 –CONTENTS
Page5FOREWORDClause SECTION 1: GENERAL1 Scope
72 Normative references
93 Definitions
93.1Insulator string 93.2Insulator set
93.3Flash-over
113.4Dry lightning impulse withstand voltage
113.550 % dry lightning impulse flash-over voltage
113.6 Wet power-frequency withstand voltage
113.7 Wet power-frequency flash-over voltage
113.8 Wet switching impulse withstand voltage
113.9 50 % wet switching impulse flash-over voltage
114 Electrical values which characterize an insulator string or an insulator set
11SECTION 2: TEST PROCEDURES FOR ELECTRICAL TESTS5 General requirements for high voltage tests
136 Standard atmospheric conditions and correction factors for electrical tests
156.1Standard reference atmosphere
156.2 Correction factors for atmospheric conditions
157 Artificial rain parameters for wet tests
158 Mounting arrangements for electrical tests
159 Lightning impulse voltage tests
1510 Wet power-frequency voltage tests
1711 Wet switching impulse voltage tests 1712 Methods of mounting
1912.1 Standard mounting arrangement of an insulator string or insulator setwhen switching impulse tests are not required
1912.2 Standard mounting arrangement of an insulator string or insulator setwhen switching impulse tests are required
2112.3 Mounting arrangement reproducing service conditions 21Annex A 23SIST EN 60383-2:1997

383-2 ©IEC:1993– 5 –INTERNATIONAL ELECTROTECHNICAL COMMISSIONINSULATORS FOR OVERHEAD LINES WITH A NOMINAL VOLTAGEABOVE 1 000 VPart 2: Insulator strings and insulator sets for a.c. systems -Definitions, test methods and acceptance criteriaFOREWORD1)The IEC (International Electrotechnical Commission) is a worldwide organization for standardizationcomprising all national electrotechnical committees (IEC National Committees). The object of the IEC is topromote international cooperation on all questions concerning standardization in the electrical andelectronic fields. To this end and in addition to other activities, the IEC publishes International Standards.Their preparation is entrusted to technical committees; any IEC National Committee interested inthe subject dealt with may participate in this preparatory work. International, governmental andnon-governmental organizations liaising with the IEC also participate in this preparation. The IECcollaborates closely with the International Organization for Standardization (ISO) in accordance withconditions determined by agreement between the two organizations.2)The formal decisions or agreements of the IEC on technical matters, prepared by technical committees onwhich all the National Committees having a special interest therein are represented, express, as nearly aspossible, an international consensus of opinion on the subjects dealt with.3)They have the form of recommendations for international use published in the form of standards, technicalreports or guides and they are accepted by the National Committees in that sense.4)In order to promote international unification, IEC National Committees undertake to apply IEC InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.International Standard IEC 383-2 has been prepared by sub-committee 36B: Insulators foroverhead lines, of IEC technical committee 36: Insulators.Part 2, together with Part 1, replaces the third edition of IEC 383 (1983) and constitutes atechnical revision.The text of this standard is based on the following documents:DISReport on Voting
36B(CO)8836B(CO)92Full information on the voting for the approval of this standard can be found in the reporton voting indicated in the above table.IEC 383 consists of the following parts, under the general title: Insulators for overheadlines with a nominal voltage above 1000 V.–Part 1: Ceramic or glass insulator units for a.c. systems – Definitions, test methodsand acceptance criteria.–Part 2: Insulator strimps and insulator sets for a.c. systems – Definitions, testmethods and acceptance criteria.Annex A is for information only.SIST EN 60383-2:1997

383-2 © IEC:1993– 7 –INSULATORS FOR OVERHEAD LINES WITH A NOMINAL VOLTAGEABOVE 1 000 VPart 2: Insulator strings and insulator sets for a.c. systems -Definitions, test methods and acceptance criteriaSection 1: General1 ScopeThis part of IEC 383 applies to insulator strings and insulator sets comprising stringinsulator units of ceramic material. or glass for use on a.c. overhead power lines with anominal voltage greater than 1 000 V and a frequency not greater than 100 Hz.This part of IEC 383 also applies to insulator strings and insulator sets for use on d.c.overhead electric traction lines.This part of IEC 383 also applies to insulator strings and insulator sets of similar designwhen used in substations.It may be regarded as a provisional standard for insulator strings and insulator sets foruse on d.c. overhead power lines and for composite insulator sets.The object of this part of IEC 383 is to prescribe standard electrical test procedures andacceptance criteria to verify the defined characteristics of insulator strings and insulatorsets falling within the scope of the part of IEC 383.These tests and characteristics are intended to give a common base to designers, usersand suppliers of overhead lines, insulators and line equipment when definition, evaluationor verification of the electrical characteristics of such equipment is required.These tests are not intended to be mandatory tests on insulators whether supplied indi-vidually or as strings or as sets.NOTES1 Tests on string insulator units are dealt with in IEC 383-1. Tests on composite insulators are dealt within IEC 1109.2 This part does not include artificial pollution or radio-interference tests. These subjects and relevanttest methods are dealt with in the following IEC reports:IEC 437: Report — radio interference test on high-voltage insulators.IEC 507: Report — artificial pollution tests on high-voltage insulators to be used on a.c. systems.3 Power arc tests are currently under study.SIST EN 60383-2:1997

383-2 © I EC:19932 Normative referencesThe following normative documents contain provisions which, through reference in thistext, constitute provisions of this part of IEC 383. At the time of publication, the editionsindicated were valid. All normative documents are subject to revision, and parties toagreements based on this part of IEC 383 are encouraged to investigate the possibility ofapplying the most recent edition of the normative documents indicated below. Membersof IEC and ISO maintain registers of currently valid International Standards.IEC 50(471): 1974, International Electrotechnical Vocabulary (lEV) - Chapter 471:InsulatorsIEC 60-1: 1989, High-voltage test techniques - Part 1: General definitions and testrequirementsIEC 71-1: 1976, Insulation co-ordination - Part 1: Terms, definitions, principles and rulesIEC 71-2: 1976, Insulation co-ordination - Part 2: Application guideIEC 71-3: 1982, Insulation co-ordination - Part 3: Phase-to-phase insulation co-ordination - Principles, rules and application guide3 DefinitionsThe definitions given below are those which either do not appear in IEC 50(471) or differfrom those given in IEC 50(471).The term "insulator" is used in this part of IEC 383 to refer to the object being tested.3.1 Insulator stringOne or more string connected insulator units and intended to give flexible support to over-head line conductors and stressed mainly in tension.3.2 Insulator setAn assembly of one or more insulator strings suitably connected together, complete withfixing and protective devices as required in service.3.2.1 Suspension insulator setAn insulator set complete with fittings to carry a line conductor or conductors at its lowerend.3.2.2 Tension insulator setAn insulator set complete with fittings to secure a line conductor or conductors in tension.SIST EN 60383-2:1997

383-2 © IEC:1993-11 -3.3 Flash-overA disruptive discharge external to the insulation, connecting those parts which normallyhave the operating voltage between them.NOTE - The term "flash-over" used in this part includes a flash-over across the insulator surface as wellas disruptive discharge by spark-over through air adjacent to the insulator.3.4 Dry lightning impulse withstand voltageThe lightning impulse voltage which the insulator withstands dry, under the prescribedconditions of test.3.5 50 % dry lightning impulse flash-over voltageThe value of the lightning impulse voltage which, under the prescribed conditions of test,has a 50 °A probability of producing flash-over on the insulator, dry.3.6 Wet power-frequency withstand voltageThe power-frequency voltage which the insulator withstands wet, under the prescribedconditions of test.3.7 Wet power-frequency flash-over voltageThe arithmetic mean of the measured voltages which cause flash-over of the insulatorunder the prescribed conditions of test.3.8 Wet switching impulse withstand voltageThe switching impulse voltage which the insulator withstands wet, under the prescribedconditions of test.3.9 50 % wet switching impulse flash-over voltageThe value of the switching impulse voltage which, under the prescribed conditions of test,has a 50 % probability of producing flash-over on the insulator, wet.4 Electrical values which characterize an insulator string or an insulator setAn insulator string or an insulator set is characterized by one or more of the followingelectrical values:a)the specified dry lightning impulse withstand voltage;b)the specified wet switching impulse withstand voltage;c)the specified wet power-frequency withstand voltage.The applicability of these characteristics as a function of the highest voltage for equipmentshall be determined by reference to IEC 71-1, 2 and 3 - Insulation co-ordination.Operating voltage is not to be considered as a characteristic of an insulator string or aninsulator set.SIST EN 60383-2:1997

383-2 ©IEC:1993– 13 –The flash-over and withstand voltages of insulators under service conditions may differfrom the flash-over and withstand voltages under standard conditions. This effect hasbeen recognized with lightning impulse testing, especially for very high voltages of equip-ment, but the effect of ambient conditions and the arrangement of insulators and associ-ated metalwork is much greater with switching impulses due to the differences in electricfield distribution between the standard test arrangement and the mounting arrangement inservice.The switching impulse withstand voltage of an insulator string or an insulator set isnot necessarily a definite characteristic because it is determined to a large extent by thetower structure and the field configuration which depends on the shape and relativepositions of all the metal parts. Therefore, the verification of the specified switchingimpulse withstand voltage is generally required with a mounting arrangement whichclosely represents service conditions. The details of the mounting arrangement shall thenbe agreed between the manufacturer and the purchaser at the time of ordering.Section 2: Test procedures for electrical tests5 General requirements for high voltage testsa)The lightning and switching impulse voltage and power-frequency voltage testmethods shall be in accordance with IEC 60-1.b)Lightning and switching impulse voltages shall be expressed by their prospectivepeak values and power-frequency voltages shall be expressed as peak values dividedbyc)When the natural atmospheric conditions at the time of the test differ from thestandard values (see 6.1), it is necessary to apply correction factors in accordancewith 6.2.d)The insulators shall be clean and dry before starting high-voltage tests.e)Special precautions shall be taken to avoid condensation on the surface of the testobject especially when the relative humidity is high. For example, the test object shallbe maintained at the ambient temperature of the test location for sufficient time forthermal equilibrium to be reached before the test starts.Except by agreement between the manufacturer and the purchaser, tests shall not bemade if the relative humidity exceeds 85 (Yo.f)The time intervals between consecutive applications of the voltage shall besufficient to minimize effects from the previous application of voltage in flash-over orwithstand tests.SIST EN 60383-2:1997

383-2 ©IEC:1993- 15 -6 Standard atmospheric conditions and correction factors for electrical tests6.1 Standard reference atmosphereThe standard reference atmospheric conditions shall be in accordance with IEC 60-1.6.2 Correction factors for atmospheric conditionsThe correction factors shall be determined in accordance with IEC 60-1. If the atmosphericconditions at the time of
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