IEC 60433:2021

Insulators for overhead lines with a nominal voltage above 1000 V - Ceramic insulators for AC systems - Characteristics of insulator units of the long rod type

IEC 60433:2021 is applicable to string insulator units of the long rod type with insulating parts of ceramic material intended for use in AC overhead power lines with a nominal voltage greater than 1000 V and a frequency not greater than 100 Hz. It is also applicable to insulators of similar design, used in substations. This document is applicable to ceramic string insulator units of the long rod type, either with a clevis end fitting at both ends for coupling with a tongue, or with a socket end fitting at both ends for coupling with a pin ball. The object of this document is to prescribe specified values for electrical and mechanical characteristics, and for the principal dimensions of ceramic string insulator units of the long rod type. This fourth edition cancels and replaces the third edition published in 1998. This edition includes the following significant technical changes with respect to the previous edition:
- wording in Scope changed from "should" to "are intended to";
- new normative references added;
- title of Clause 4 amended, new Note 4 added;
- Table 1 expanded to include more specified mechanical failing loads.

Isolateurs pour lignes aériennes de tension nominale supérieure à 1 000 V - Isolateurs en céramique pour réseaux à tension alternative - Caractéristiques des éléments d'isolateurs du type à long fût

L'IEC 60433:2021 s'applique aux éléments de chaînes d'isolateurs du type à long fût ayant des parties isolantes en matière céramique destinés aux lignes aériennes fonctionnant en courant alternatif à une tension nominale supérieure à 1 000 V et à une fréquence au plus égale à 100 Hz. Elle s'applique également aux isolateurs du même type utilisés dans les postes. Le présent document s'applique aux éléments de chaînes d’isolateurs en céramique du type à long fût ayant à chaque extrémité soit une chape destinée à recevoir un tenon, soit un logement de rotule pour assemblage avec une tige à rotule. Le présent document a pour objet de prescrire des valeurs spécifiées pour les caractéristiques électriques et mécaniques et pour les principales dimensions des éléments de chaînes d'isolateurs en céramique du type à long fût. Cette quatrième édition annule et remplace la troisième édition parue en 1998. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- reformulation du domaine d'application: "il convient d’utiliser les caractéristiques mécaniques ainsi que les longueurs L (voir Article 4) de la présente norme " remplacé par "les caractéristiques mécaniques ainsi que les longueurs L (voir Article 4) de la présente norme sont prévues pour être utilisées";
- ajout de nouvelles références normatives;
- modification du titre de l'Article 4, ajout d'une nouvelle Note 4;
- Le Tableau 1 a été étoffé pour intégrer un plus grand nombre de charges de rupture mécanique spécifiées.

General Information

• Status: Published
• Publication Date: 11-Jan-2021
• ICS: 29.080.10 - Insulators
• ICS: 29.240.20 - Power transmission and distribution lines
• Technical Committee: TC 36 - Insulators
• Drafting Committee: MT 17 - TC 36/MT 17
• Current Stage: PPUB - Publication issued
• Start Date: 20-Jan-2021
• Completion Date: 12-Jan-2021

Relations

• Revises: IEC 60433:1998 - Insulators for overhead lines with a nominal voltage above 1 000 V - Ceramic insulators for a.c. systems - Characteristics of insulator units of the long rod type
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60433 ®
Edition 4.0 2021-01
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Insulators for overhead lines with a nominal voltage above 1 000 V – Ceramic
insulators for AC systems – Characteristics of insulator units of the long rod
type
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
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International Standards for all electrical, electronic and related technologies.

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IEC 60433 ®
Edition 4.0 2021-01
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Insulators for overhead lines with a nominal voltage above 1 000 V – Ceramic

insulators for AC systems – Characteristics of insulator units of the long rod

type
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.080.10; 29.240.20 ISBN 978-2-8322-9280-8

– 2 – IEC 60433:2021 RLV © IEC 2021
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Characteristics, dimensions and type of long rod insulators . 6
5 Designation and marking . 7
Bibliography . 11

Figure 1 – Long rod insulator with clevis couplings, type C . 10
Figure 2 – Long rod insulator with socket couplings, type B . 10

Table 1 – Specified values for long rod insulators . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATORS FOR OVERHEAD LINES
WITH A NOMINAL VOLTAGE ABOVE 1 000 V –
CERAMIC INSULATORS FOR AC SYSTEMS –
CHARACTERISTICS OF INSULATOR UNITS OF THE LONG ROD TYPE

FOREWORD
1) 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.
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 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 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 Publication 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 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 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.
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 subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition IEC 60433:1998. A vertical bar appears in the margin
wherever a change has been made. Additions are in green text, deletions are in
strikethrough red text.
– 4 – IEC 60433:2021 RLV © IEC 2021
International Standard IEC 60433 has been prepared by IEC technical committee 36:
Insulators.
This fourth edition cancels and replaces the third edition published in 1998. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) wording in Scope changed from "should" to "are intended to";
b) new normative references added;
c) title of Clause 4 amended, new Note 4 added;
d) Table 1 expanded to include more specified mechanical failing loads.
The text of this International Standard is based on the following documents:
FDIS Report on voting
36/498/FDIS 36/500/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INSULATORS FOR OVERHEAD LINES
WITH A NOMINAL VOLTAGE ABOVE 1 000 V –
CERAMIC INSULATORS FOR AC SYSTEMS –
CHARACTERISTICS OF INSULATOR UNITS OF THE LONG ROD TYPE

1 Scope
This International Standard is applicable to string insulator units of the long rod type with
insulating parts of ceramic material intended for use in AC overhead power lines with a
nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It is also
applicable to insulators of similar design, used in substations.
This document is applicable to ceramic string insulator units of the long rod type, either with a
clevis end fitting at both ends for coupling with a tongue, or with a socket end fitting at both
ends for coupling with a pin ball.
The object of this document is to prescribe specified values for electrical and mechanical
characteristics, and for the principal dimensions of ceramic string insulator units of the long
rod type.
This document is applicable to string insulator units for use on overhead lines situated in
lightly polluted areas, and the creepage distances given in Table 1 have been established
accordingly, using the IEC TS 60815-2 recommendation of 16 mm/kV for pollution level I 27,8
mm/kV for SPS class. However, shorter creepage distances may be used are applicable for
use in some non-polluted areas. If specific operating conditions require or allow non-standard
(longer or shorter) creepage distances, the mechanical characteristics as well as the lengths
L (see Clause 4) of this document should are intended to be used unless the need for
exceptionally long creepage distances requires values of L greater than those given in Table
1. In the case of special requirements, e.g. very heavy polluted areas and for other particular
or extreme environmental conditions, it may be necessary for certain dimensions to be
changed.
NOTE As far as reasonably applicable, this document may is also applicable to be applied to
similar insulator units outside the scope of this standard, such as insulators for electric
traction lines. This document does not include tests on insulators and dimensions of end
fittings.
NOTE Ball and socket couplings are covered by IEC 60120, clevis and tongue couplings by
IEC 60471.
NOTE 1 For the definition of site pollution levels severity, see applicable part of IEC TS 60815.
NOTE 2 The term "ceramic" is used in this document to refer to porcelain materials and, contrary to North
American practice, does not include glasses.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 60071-1:1993, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60120:1984, Dimensions of ball and socket couplings of string insulator units

– 6 – IEC 60433:2021 RLV © IEC 2021
IEC 60383-1:1993, Insulators for overhead lines with a nominal voltage above 1 000 V – Part
1: Ceramic or glass insulator units for AC systems – Definitions, test methods and acceptance
criteria
IEC 60471:1977, Dimensions of clevis and tongue couplings of string insulator units
IEC 60672-1:1995, Ceramic and glass insulating materials – Part 1: Definitions and
classification
IEC 60672-3:1997, Ceramic and glass insulating materials – Part 3: Specification for
individual materials
IEC 60815:1986 Guide for the selection of insulators in respect of polluted conditions
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
long rod insulator
suspension or tension insulator consisting of an approximately cylindrical insulating part
provided with sheds and equipped at the ends with external metal fittings
Note 1 to entry: The insulator is designed in such a manner that the shortest puncture path through solid
insulating material is at least equal to half the arcing distance. Therefore it is a class A insulator according to
IEC 60383-1.
4 Characteristics, dimensions and type of long rod insulators
String insulator units of the long rod type are characterised by the following specified
characteristics:
– the standard lightning impulse wit
...

IEC 60433 ®
Edition 4.0 2021-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulators for overhead lines with a nominal voltage above 1 000 V – Ceramic
insulators for AC systems – Characteristics of insulator units of the long rod
type
Isolateurs pour lignes aériennes de tension nominale supérieure a 1 000 V –
Isolateurs en céramique pour réseaux à tension alternative – Caractéristiques
des éléments d'isolateurs du type a long fût

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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 60433 ®
Edition 4.0 2021-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Insulators for overhead lines with a nominal voltage above 1 000 V – Ceramic

insulators for AC systems – Characteristics of insulator units of the long rod

type
Isolateurs pour lignes aériennes de tension nominale supérieure a 1 000 V –

Isolateurs en céramique pour réseaux à tension alternative – Caractéristiques

des éléments d'isolateurs du type a long fût

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.080.10; 29.240.20 ISBN 978-2-8322-9204-4

– 2 – IEC 60433:2021 © IEC 2021
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Characteristics, dimensions and type of long rod insulators . 6
5 Designation and marking . 6
Bibliography . 11

Figure 1 – Long rod insulator with clevis couplings, type C . 10
Figure 2 – Long rod insulator with socket couplings, type B . 10

Table 1 – Specified values for long rod insulators . 8

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATORS FOR OVERHEAD LINES
WITH A NOMINAL VOLTAGE ABOVE 1 000 V –
CERAMIC INSULATORS FOR AC SYSTEMS –
CHARACTERISTICS OF INSULATOR UNITS OF THE LONG ROD TYPE

FOREWORD
1) 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.
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 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 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 Publication 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 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 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.
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 subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60433 has been prepared by IEC technical committee 36:
Insulators.
This fourth edition cancels and replaces the third edition published in 1998. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) wording in Scope changed from "should" to "are intended to";
b) new normative references added;
c) title of Clause 4 amended, new Note 4 added;
d) Table 1 expanded to include more specified mechanical failing loads.

– 4 – IEC 60433:2021 © IEC 2021
The text of this International Standard is based on the following documents:
FDIS Report on voting
36/498/FDIS 36/500/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
INSULATORS FOR OVERHEAD LINES
WITH A NOMINAL VOLTAGE ABOVE 1 000 V –
CERAMIC INSULATORS FOR AC SYSTEMS –
CHARACTERISTICS OF INSULATOR UNITS OF THE LONG ROD TYPE

1 Scope
This International Standard is applicable to string insulator units of the long rod type with
insulating parts of ceramic material intended for use in AC overhead power lines with a
nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It is also
applicable to insulators of similar design, used in substations.
This document is applicable to ceramic string insulator units of the long rod type, either with a
clevis end fitting at both ends for coupling with a tongue, or with a socket end fitting at both
ends for coupling with a pin ball.
The object of this document is to prescribe specified values for electrical and mechanical
characteristics, and for the principal dimensions of ceramic string insulator units of the long
rod type.
This document is applicable to string insulator units for use on overhead lines situated in
lightly polluted areas, and the creepage distances given in Table 1 have been established
accordingly, using the IEC TS 60815-2 recommendation of 27,8 mm/kV for SPS class.
However, shorter creepage distances are applicable for use in some non-polluted areas. If
specific operating conditions require or allow non-standard (longer or shorter) creepage
distances, the mechanical characteristics as well as the lengths L (see Clause 4) of this
document are intended to be used unless the need for exceptionally long creepage distances
requires values of L greater than those given in Table 1. In the case of special requirements,
e.g. very heavy polluted areas and for other particular or extreme environmental conditions, it
may be necessary for certain dimensions to be changed.
As far as reasonably applicable, this document is also applicable to be applied to similar
insulator units outside the scope of this standard, such as insulators for electric traction lines.
This document does not include tests on insulators and dimensions of end fittings.
Ball and socket couplings are covered by IEC 60120, clevis and tongue couplings by
IEC 60471.
NOTE 1 For the definition of site pollution severity, see applicable part of IEC TS 60815.
NOTE 2 The term "ceramic" is used in this documen
...