IEC 60383-1:2023

IEC 60383-1 ®
Edition 5.0 2023-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Insulators for overhead lines with a nominal voltage above 1000 V –
Part 1: Ceramic or glass insulator units for a.c. systems – Definitions, test
methods and acceptance criteria

Isolateurs pour lignes aériennes de tension nominale supérieure à 1 000 V –
Partie 1: Éléments d’isolateurs en matière céramique ou en verre pour systèmes
à courant alternatif – Définitions, méthodes d’essai et critères d’acceptation
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IEC 60383-1 ®
Edition 5.0 2023-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Insulators for overhead lines with a nominal voltage above 1000 V –

Part 1: Ceramic or glass insulator units for a.c. systems – Definitions, test

methods and acceptance criteria

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

Partie 1: Éléments d’isolateurs en matière céramique ou en verre pour systèmes

à courant alternatif – Définitions, méthodes d’essai et critères d’acceptation

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.080.10, 29.240.20 ISBN 978-2-8322-7128-5

– 2 – IEC 60383-1:2023 © IEC 2023
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 10
4 Classification, types of insulators and insulating materials . 13
4.1 Insulator classes . 13
4.2 Insulator types . 14
4.3 Insulating materials . 14
5 Identification of insulators . 14
6 Classification of tests. 14
6.1 Type tests . 14
6.2 Sample tests . 15
6.3 Routine tests. 15
7 Cross-reference tables for tests to be performed . 15
7.1 Pin insulators . 15
7.2 Line post insulators . 17
7.3 String insulator units . 19
7.3.1 General . 19
7.3.2 Specified type tests on string insulator units . 20
7.4 Insulators for overhead electric traction lines . 24
8 Procedures for type and sample tests . 24
8.1 Insulator selection for type tests . 24
8.2 Sampling rules and procedures for sample tests . 24
8.3 Re-test procedure for sample tests . 25
9 General requirements for electrical tests . 25
10 Artificial rain parameters for wet tests . 26
11 Mounting arrangements for electrical tests . 26
12 Dry lightning impulse voltage tests . 26
12.1 General . 26
12.2 Test procedure . 26
12.3 Acceptance criteria . 26
13 Wet power frequency withstand voltage tests . 27
13.1 Test procedure . 27
13.2 Acceptance criteria . 27
14 RIV test . 27
14.1 Test procedure . 27
14.2 Acceptance criteria . 28
15 Puncture withstand test . 28
15.1 General . 28
15.2 Impulse puncture testing in air . 28
15.3 Power frequency puncture withstand test . 29
16 Routine electrical test . 29
17 Verification of the dimensions . 30
18 Electromechanical failing load test . 30

18.1 Test procedure . 30
18.2 Acceptance criteria . 31
19 Mechanical failing load test. 31
19.1 Test procedure for pin and line post insulators . 31
19.2 Test procedure for string insulator units . 31
19.3 Acceptance criteria for pin insulators . 31
19.4 Acceptance criteria for string insulator units and line post insulators . 31
20 Thermal-mechanical performance test . 32
20.1 Test procedure . 32
20.2 Acceptance criteria . 33
21 Residual strength test . 33
21.1 General . 33
21.2 Previous tests . 33
21.3 Preparation of the test pieces . 33
21.4 Test procedure . 34
21.5 Test results . 34
21.6 Acceptance criteria . 34
22 Verification of the axial, radial and angular displacements . 34
22.1 Test procedure . 34
22.2 Acceptance criteria . 35
23 Verification of the locking system . 36
23.1 General . 36
23.2 Conformity of the locking device . 36
23.3 Verification of locking . 36
23.4 Position of the locking device . 36
23.5 Procedure for the operation test . 36
23.6 Acceptance criteria for the operation test . 37
24 Temperature cycle test . 37
24.1 Test procedure for ceramic or toughened glass material . 37
24.2 Test procedure for of annealed glass . 38
24.3 Special test procedure for insulators with thick sections or very large
insulators . 38
24.4 Complementary specifications . 38
24.5 Acceptance criteria . 38
25 Thermal shock test . 39
25.1 Sample test . 39
25.1.1 Test procedure . 39
25.1.2 Acceptance criteria . 39
25.2 Routine thermal shock test . 39
25.2.1 Test procedure . 39
25.2.2 Acceptance criteria . 39
26 Porosity test . 39
26.1 Test procedure . 39
26.2 Acceptance criteria . 39
27 Galvanizing test . 40
27.1 General . 40
27.2 Test procedure . 40
27.2.1 General . 40

– 4 – IEC 60383-1:2023 © IEC 2023
27.2.2 Appearance . 40
27.2.3 Determination of the coating mass by the magnetic test method . 40
27.3 Acceptance criteria . 40
27.3.1 Acceptance criteria for the appearance test . 40
27.3.2 Acceptance criteria for the value of coating mass . 41
28 Zinc sleeve test (if applicable) . 41
28.1 General requirements concerning the zinc sleeve . 41
28.2 Type test procedure . 41
28.3 Sample test procedure . 42
29 Routine visual inspection . 42
29.1 General . 42
29.2 Insulators with ceramic insulating parts . 42
29.3 Insulators with glass insulating parts . 43
30 Impact test . 44
30.1 Test procedure . 44
30.2 Acceptance criteria . 44
31 Routine mechanical test . 44
31.1 Routine mechanical test on line post insulators . 44
31.2 Routine mechanical test on string insulator units . 45
32 Mounting arrangements for tests on pin insulators . 45
32.1 Standard mounting arrangement for electrical tests . 45
32.2 Mounting arrangements for electrical tests reproducing service conditions . 46
32.3 Mounting arrangement for the mechanical failing load test . 46
33 Coefficients for statistical analysis of the test results on line post Insulators . 46
33.1 Coefficient for type tests . 46
33.2 Coefficients for sample tests . 46
34 Mounting arrangements for tests on line post insulators . 46
34.1 Standard mounting arrangement for electrical tests . 46
34.2 Mounting arrangements for electrical tests reproducing service conditions . 47
34.3 Mounting arrangement for the mechanical failing load test . 47
35 Coefficients for statistical analysis of the test results on string insulator units . 47
35.1 Coefficient for type tests . 47
35.2 Coefficients for sample tests . 48
36 Mounting arrangements for electrical tests on string insulator units . 48
37 Mounting arrangements for electrical tests on Insulators for overhead electric

traction lines . 48
37.1 Standard mounting arrangement . 48
37.2 Mounting arrangement representing service conditions . 49
Annex A (informative) Method of comparison of the results of electromechanical or
and sample tests . 52
mechanical type
Annex B (informative) Illustration of the mechanical and electromechanical test
acceptance procedure for string insulator units and line post insulators . 54
B.1 Flow charts . 54
B.2 Calculated examples of acceptance and rejection . 56
Annex C (informative) Coatings on ceramic or glass insulators . 59
C.1 General . 59
C.2 Material fingerprinting and ageing performance . 59
C.3 Type testing . 59

C.4 Sample testing . 60
C.5 Routine testing . 60
C.6 Pollution performance . 60
C.7 Acceptance criteria . 60
Annex D (informative) Impact test . 62

Figure 1 – Schematic representation of the thermal-mechanical performance test . 49
Figure 2 – Measurement of axial and radial displacements . 50
Figure 3 – Measurement of angular displacement . 50
Figure 4 – Greatest thickness of the insulator . 51
Figure B.1 – Acceptance flow chart for mechanical or electromechanical type tests . 54
Figure B.2 – Acceptance flow chart for mechanical or electromechanical sample tests . 55
Figure B.3 – Flow chart of the comparison of type and sample tests . 56
Figure C.1 – Example of thickness criteria based on current experience . 60
Figure C.2 – Example of adherence test criteria . 61
Figure D.1 – Example of equipment for impact testing . 62

Table 1 – Cross-reference table for pin insulators . 17
Table 2 – Cross-reference table for line post insulators . 19
Table 3 – Cross-reference table for string insulator units – cap and pin . 21
Table 4 – Cross-reference table for string insulator units – long rod . 23
Table 5 – Sample sizes for sample tests . 25
Table 6 – Acceptance criteria for impact test. 44
Table 7 – Coefficients for sample tests (line post insulators) . 46
Table 8 – Coefficients for sample tests (string insulator units) . 48
Table A.1 – Values for constants a, b and c . 52
Table A.2 – Values for constants a, b and c (re-test) . 53
Table B.1 – Examples for mechanical and electromechanical sample tests . 57
Table B.2 – Blank form for calculation for mechanical and electromechanical

sample tests . 58

– 6 – IEC 60383-1:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
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

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
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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.
IEC 60383 has been prepared by IEC technical committee 36: Insulators. It is an International
Standard.
This fifth edition cancels and replaces the fourth edition published in 1993. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The complete document has been revised and updated. The layout of the document has
been changed in order to increase readability;
b) RIV test has been added (Clause 14);
c) Impulse puncture test in air has been added (15.2);
d) Residual strength test has been added (Clause 21);

e) Zinc sleeve test has been added (Clause 28);
f) Impact test has been added (Clause 30);
g) Annex C, coatings on ceramic and glass insulators has been added;
h) Annex D, impact test has been added.
The text of this International Standard is based on the following documents:
Draft Report on voting
36/564/FDIS 36/571/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 60383 series, published under the general title Insulators for
overhead lines with a nominal voltage above 1 000 V, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under 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 document 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.

– 8 – IEC 60383-1:2023 © IEC 2023
INTRODUCTION
This part of IEC 60383 deals with four different types of insulators:
• Pin insulators
• Line post insulators
• String insulator units
• Insulators for overhead electric traction lines
Certain clauses of this document contain general requirements and other clauses contain
specific tests relevant to each of the above-mentioned insulators.

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

1 Scope
This part of IEC 60383 applies to insulators of ceramic material or glass for use on AC overhead
power lines and overhead traction lines with a nominal voltage greater than 1 000 V and a
frequency not greater than 100 Hz. It also applies to insulators for use on DC overhead electric
traction lines.
This document applies to string insulator units, rigid overhead line insulators and to insulators
of similar design when used in substations.
lt does not apply to insulators forming parts of electrical apparatus or to parts used in their
construction or to post insulators which are covered by IEC 60168, Tests on indoor and outdoor
post insulators of ceramic material or glass for systems with nominal voltages greater than
1 000 V.
Tests on insulator strings and insulator sets (for example, wet switching impulse voltage) are
dealt with in IEC 60383-2.
The object of this document is:
– to define the terms used
– to define insulator characteristics and to prescribe the conditions under which the specified
values of these characteristics shall be verified
– to prescribe test methods
– to prescribe acceptance criteria.
This document does not include requirements dealing with the choice of insulators for specific
operating conditions.
Specific requirements on the use of coatings on ceramic or glass insulators are described in
the informative Annex C.
Numerical values for insulator characteristics are specified in IEC 60305, IEC 60433 and
IEC 60720.
NOTE A guide for the choice of insulators under polluted conditions has been published, see IEC 60815-1 and -2.
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 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements

– 10 – IEC 60383-1:2023 © IEC 2023
IEC 60120, Ball and socket couplings of string insulator units – Dimensions
IEC 60305, Insulators for overhead lines with a nominal voltage above 1000 V – Ceramic or
glass insulator units for AC systems – Characteristics of insulator units of the cap and pin type
IEC 60372, Locking devices for ball and socket couplings of string insulator units – Dimensions
and tests
IEC 60433, 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 60437, Radio interference test on high-voltage insulators
IEC 60471, Clevis and tongue couplings of string insulator units – Dimensions
IEC 61211, Insulators of ceramic material or glass for overhead lines with a nominal voltage
greater than 1 000 V – Impulse puncture testing in air
ISO 1459:1973, Metallic coatings – Protection against corrosion by hot dip galvanizing –
Guiding principles
ISO 1460, Metallic coatings – Hot dip galvanized coatings on ferrous metals – Determination of
the mass per unit area – Gravimetric method
ISO 1461, Hot dip galvanized coatings on fabricated iron and steel articles – Specifications and
test Methods
ISO 1463, Metal and oxide coatings – Measurement of coating thickness – Microscopical
method
ISO 2064, Metallic and other non-organic coatings – Definitions and conventions concerning
the measurement of thickness
ISO 2178:2016, Non-magnetic coatings on magnetic substrates – Measurement of coating
thickness – Magnetic method
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
insulator string
one or more string insulator units coupled together and intended to give flexible support to
conductors and stressed mainly in tension
3.2
rigid insulator
insulator intended to give rigid support to an overhead line conductor and to be stressed mainly
by bending and compressive loads

3.3
long rod insulator
rigid insulator intended to be subjected to tensile loads, comprising an insulating part having
an approximately circular cylindrical shank, with or without sheds, and external or internal fixing
devices attached to each end
3.4
cap and pin insulator
insulator comprising an insulating part usually having the form of a disk or bell, with or without
ribs on its surface, and end fittings consisting of an outside cap and an inside pin attached
axially
3.5
pin insulator
rigid insulator consisting of an insulating component intended to be mounted rigidly on a
supporting structure by means of a pin passing up inside the insulating component which
consists of one or more pieces of insulating material permanently connected together
Note 1 to entry: The pin can have two basic shapes. With one shape, the insulating component is fixed to the end
of the pin and does not allow contact of the insulating component with the supporting structure. With the other shape,
the insulating component is fixed by means of the pin in contact with the supporting structure either directly or with
a plate in between, the plate being either a separate washer or part of the pin (sometimes referred to as a pin post
insulator).
3.6
line post insulator
rigid insulator intended to be subjected to cantilever, tensile and compressive loads,
constructed with one or more insulating materials and assembled on a metal base that is
intended to be mounted rigidly on a supporting structure
3.7
traction insulator
insulator or insulator set intended to give flexible or rigid support for overhead electric traction
lines. All types of overhead line insulators may be used for this purpose.
3.8
annealed glass
glass which has been treated to eliminate internal stresses
3.9
toughened glass
glass in which pre-stresses have been created in order to improve its mechanical characteristics
3.10
lot
group of insulators offered for acceptance from the same manufacturer, of the same design and
manufactured under presumed similar conditions of production
Note 1 to entry: One or more lots may be offered together for acceptance; the lot(s) offered may consist of the
whole, or part, of the quantity ordered.
3.11
flashover (of an insulator)
disruptive discharge external to the insulator, and over its surface, connecting those parts which
normally have the operating voltage between them
3.12
impulse withstand voltage
highest peak value of impulse voltage of prescribed form and polarity which does not cause
breakdown of insulation under specified conditions

– 12 – IEC 60383-1:2023 © IEC 2023
3.13
power frequency withstand voltage
RMS value of sinusoidal power frequency voltage that the insulation of the given equipment can
withstand during tests made under specified conditions and for a specified duration
3.14
electromechanical failing load
maximum load reached when a string insulator unit is tested under the prescribed conditions of
the test
3.15
mechanical failing load
maximum load reached when an insulator is tested under the prescribed conditions of test
3.16
specified mechanical failing load, SFL
mechanical load that causes the loss of mechanical characteristics of any part of an insulator,
when tested according to the relevant standard
Note 1 to entry: SFL can also be used for specified electromechanical failing load.
3.17
puncture (of an insulator)
disruptive discharge passing through the solid insulating material of the insulator which
produces a permanent loss of dielectric strength
3.18
creepage distance
shortest distance or the sum of the shortest distances along the surface on an insulator between
two conductive parts which normally have the operating voltage between them
Note 1 to entry: The surface of cement or of any other non-insulating jointing material is not considered as forming
part of the creepage distance.
Note 2 to entry: If a high resistance coating is applied to parts of the insulating part of an insulator, such parts are
considered to be effective insulating surfaces and the distance over them is included in the creepage distance.
Note 3 to entry: Insulators with grooves e.g. pin insulators, the creepage measurements shall start at the centre of
the side groove.
3.19
minimum creepage distance
defined minimum allowed creepage distance which cannot be subject to a specified negative
tolerance
3.20
nominal creepage distance
value of the creepage distance which can also be subject to a specified positive or negative
tolerance
3.21
minimum nominal creepage distance
defined minimum allowed creepage distance which can also be subject to a specified negative
tolerance
Note 1 to entry: Minimum nominal creepage distance is a definition that normally applies to cap and pin insulators.

3.22
displacements
axial displacement
maximum positional variation, parallel to the insulator axis, of a definite point on the
circumference of the considered insulator during one complete revolution around the insulator
axis
radial displacement
maximum positional variation, perpendicular to the insulator axis, of a definite point on the
circumference of the considered insulator during one complete revolution around the insulator
axis
angular displacement
angular deviation around the insulator axis between corresponding planes of the two coupling
pieces
3.23
short standard string
string used to verify characteristics of a unit which are significant only to an insulator string
insulator string of 5 insulator units
insulator string between 1 m and 2 m in length for long rod
insulator units intended to be assembled in a string
Note 1 to entry: For long rod insulators less than 1 m long intended to be used as a string, the unit itself is
considered as a short standard string.
Note 2 to entry: The definition short standard string is different to the definition of short string in IEC 61467.
Note 3 to entry: For systems with insulator string with less than 5 insulators, must be considered the string with the
real number of insulators.
3.24
specified characteristic
numeric value of a voltage or of a mechanical load or any other characteristic
specified in an IEC international standard
numeric value of any such characteristic agreed between the purchaser and the
manufacturer
4 Classification, types of insulators and insulating materials
4.1 Insulator classes
Insulators for overhead lines are divided into two classes according to their design:
Class A: an insulator or string insulator unit in which the length of the shortest puncture path
through solid
...