SIST EN 60660:2001

Insulators - Tests on indoor post insulators of organic material for systems with nominal voltages greater than 1 kV up to but not including 300 kV

Applicable to post insulators of organic material for indoor service in electrical installations or equipment operating in air at atmospheric pressure on alternating current with a nominal voltage greater than 1 000 V up, but not including, 300 kV, as defined by range I of EN 60071-1, and a frequency not greater than 100 Hz. Composite insulators are not covered by this standard. The object of this standard is - to define the terms used, - define electrical and mechanical characteristics of post insulators of organic material and to prescribe the conditions under which the specified values of these characteristics are verified, - to prescribe methods of testing, - to prescribe acceptance criteria. This standard does not give numerical values for insulator characteristics, nor does it deal with a choice of insulators for specific operating conditions. HD 578 S1 specifies numerical values for electrical and mechanical characteristics and gives the dimensions necessary for interchangeability of post insulators.

Isolatoren - Prüfungen an Innenraum-Stützern aus organischem Werkstoff für Netze mit Nennspannungen über 1 kV bis kleiner 300 kV

Isolateurs - Essais des supports isolants d'intérieur en matière organique destinés à des installations de tension nominale supérieure à 1 kV jusqu'à 300 kV non compris

Est applicable aux supports isolants d'intérieur en matière organique destinés à l'équipement d'installations ou d'appareils électriques fonctionnant dans l'air, à la pression atmosphérique, en courant alternatif, à une tension nominale supérieure à 1000 V jusqu'à 300 kV non compris et à une fréquence au plus égale à 100 Hz comme défini dans la gamme I de la EN 60071-1. Les isolateurs composites ne sont pas couverts par la présente norme. La présente norme a pour objet de: définir les termes employés; définir les caractéristiques électriques et mécaniques des supports isolants en matière organique et de fixer les conditions dans lesquelles les valeurs spécifiées de ce caractéristiques doivent être vérifiées; prescrire les méthodes d'essai; fixer les conditions d'acceptation. Cette norme ne donne pas de valeur numérique pour les caractéristiques des isolateurs et ne contient pas de prescriptions relatives au choix d'un isolateur en fonction du service qu'il doit assurer. La HD 578 S1 spécifie les valeurs numériques pour les caractéristiques électriques et mécaniques, et donne les dimensions nécessaires à l'interchangeabilité des supports isolants.

Insulators - Tests on indor post insulators of organic material for systems with nominal voltages greater than 1 kV up to but not including 300 kV (IEC 60660:1999)

General Information

• Status: Published
• Publication Date: 31-Jan-2001
• ICS: 29.080.10 - Insulators
• Technical Committee: IZL - Insulators
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Feb-2001
• Due Date: 01-Feb-2001
• Completion Date: 01-Feb-2001
• Ref Project: EN 60660:1999 - Insulators - Tests on indoor post insulators of organic material for systems with nominal voltages greater than 1 kV up to but not including 300 kV

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60660:2001
01-februar-2001
Insulators - Tests on indor post insulators of organic material for systems with
nominal voltages greater than 1 kV up to but not including 300 kV (IEC 60660:1999)
Insulators - Tests on indoor post insulators of organic material for systems with nominal
voltages greater than 1 kV up to but not including 300 kV
Isolatoren - Prüfungen an Innenraum-Stützern aus organischem Werkstoff für Netze mit
Nennspannungen über 1 kV bis kleiner 300 kV
Isolateurs - Essais des supports isolants d'intérieur en matière organique destinés à des
installations de tension nominale supérieure à 1 kV jusqu'à 300 kV non compris
Ta slovenski standard je istoveten z: EN 60660:1999
ICS:
29.080.10 Izolatorji Insulators
SIST EN 60660:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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NORME CEI
INTERNATIONALE IEC
60660
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1999-10
Isolateurs –
Essais des supports isolants d'intérieur en matière
organique destinés à des installations de tension
nominale supérieure à 1 000 V jusqu'à 300 kV
non compris
Insulators –
Tests on indoor post insulators of organic material
for systems with nominal voltages greater than
1 000 V up to but not including 300 kV
 IEC 1999 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun procédé, any form or by any means, electronic or mechanical,
électronique ou mécanique, y compris la photo-copie et les including photocopying and microfilm, without permission in
microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
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Telefax: [phone] e-mail: [e-mail] IEC web site http://www.iec.ch
CODE PRIX
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U
PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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60660 © IEC:1999 – 3 –
CONTENTS
Page
FOREWORD . 5
Clause
1 General. 9
1.1 Scope and object . 9
1.2 Normative references. 9
1.3 Definitions. 11
1.4 Values which characterise a post insulator of organic material. 15
1.5 Documentation. 17
1.6 Normal service conditions . 17
2 General requirements for tests . 17
2.1 Classification of tests . 17
2.2 Quality assurance . 19
2.3 General requirements for electrical tests . 19
2.4 Lightning impulse voltage tests. 21
2.5 Power-frequency voltage tests. 21
2.6 Standard reference atmospheric conditions for tests. 21
2.7 Correction factors for atmospheric conditions . 21
3 Type tests . 21
3.1 General. 21
3.2 General requirements for electrical type tests . 25
3.3 Dry lightning impulse withstand voltage test. 27
3.4 Dry power-frequency withstand voltage test . 29
3.5 Partial discharge extinction voltage test. 29
3.6 Lightning impulse puncture test . 29
3.7 Mechanical failing load test . 31
3.8 Test for deflection under load at normal ambient temperature conditions . 33
3.9 Test for mechanical bending strength as a function of temperature . 33
3.10 Water absorption test. 37
3.11 Ageing and humidity test . 37
3.12 Flammability test. 37
3.13 Temperature cycle test. 37
4 Sample tests . 39
4.1 General. 39
4.2 Verification of dimensions . 41
4.3 Re-test procedure . 41
5 Routine tests.43
5.1 General. 43
5.2 Visual examination . 43
5.3 Mechanical routine test . 43
5.4 Electrical routine test and partial discharge measurement. 45
Annex A (informative) Tolerances of form and position. 47

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60660 © IEC:1999 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSULATORS – TESTS ON INDOOR POST INSULATORS OF
ORGANIC MATERIAL FOR SYSTEMS WITH NOMINAL
VOLTAGES GREATER THAN 1 000 V UP TO BUT
NOT INCLUDING 300 kV
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports 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 International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60660 has been prepared by subcommittee 36C: Insulators for
substations, of IEC technical committee 36: Insulators.
This second edition cancels and replaces the first edition published in 1979 and constitutes a
technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
36C/111/FDIS 36C/114/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 3.
Annex A is for information only.

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60660 © IEC:1999 – 7 –
The committee has decided that this publication remains valid until 2006.
At this date, in accordance with the committee’s decision, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

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60660 © IEC:1999 – 9 –
INSULATORS – TESTS ON INDOOR POST INSULATORS OF
ORGANIC MATERIAL FOR SYSTEMS WITH NOMINAL
VOLTAGES GREATER THAN 1 000 V UP TO BUT
NOT INCLUDING 300 kV
1 General
1.1 Scope and object
This International Standard is applicable to post insulators of organic material for indoor
service in electrical installations or equipment operating in air at atmospheric pressure on
alternating current with a nominal voltage greater than 1 000 V up to, but not including, 300 kV,
as defined by range I of IEC 60071-1, and a frequency not greater than 100 Hz. Composite
insulators are not covered by this standard.
The object of this standard is
– to define the terms used;
– to define electrical and mechanical characteristics of post insulators of organic material
and to prescribe the conditions under which the specified values of these characteristics
are verified;
– to prescribe methods of testing;
– to prescribe acceptance criteria.
This standard does not give numerical values for insulator characteristics; nor does it deal with
a choice of insulators for specific operating conditions. IEC 60273 specifies numerical values
for electrical and mechanical characteristics and gives the dimensions necessary for inter-
changeability of post insulators.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of the ISO/IEC Directives. For dated references, subsequent
amendments to, or revisions of, any of these publications do not apply. However, parties to
agreements based on this part of the ISO/IEC Directives are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below.
For undated references, the latest edition of the normative document referred to applies.
Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60050(471):1984, International Electrotechnical Vocabulary (IEV) – Chapter 471:
Insulators
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60270, Partial discharge measurements
IEC 60273, Characteristics of indoor and outdoor post insulators for systems with nominal
voltages greater than 1 000 V
IEC 60587, Test method for evaluating resistance to tracking and erosion of electrical
insulating materials used under severe ambient conditions

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60660 © IEC:1999 – 11 –
IEC 60695-11-10:1999, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and
vertical flame test methods
IEC 60932, Additional requirements for enclosed switchgear and controlgear from 1 kV
to 72,5 kV to be used in severe climatic conditions
ISO 9000-1, Quality management and quality assurance standards – Part 1: Guidelines for
selection and use
ISO 9002, Quality systems – Model for quality assurance in production, installation and
servicing
1.3 Definitions
For the purpose of this standard, the following definitions apply, together with those in
IEC 60050(471)
NOTE – The definitions regarding test voltages are given for convenience. For additional details, see IEC 60060-1.
1.3.1
post insulator of organic material
post insulator intended to give rigid support to a live part which is to be insulated from earth
and from another live part. The whole or part of the material composing the post insulator
consists of organic materials, i.e. of material pertaining to the chemistry of the compounds
produced from carbon or to the chemistry of the compounds produced from carbon and silicon.
These organic materials may be used alone or in conjunction with other materials (mineral or
organic) as fillers, reinforcements, etc.
1.3.2
indoor post insulator
a post insulator not intended to be exposed to outdoor atmospheric conditions. For indoor
installations subject to excessive condensation, outdoor post insulators or special indoor post
insulators may be used
[IEV 471-04-04, modified]
1.3.3
design category
post insulators of organic materials are divided into two different design categories according
to their construction. The design categories covered by this standard are:
Design category A
Cylindrical post insulators with internal metal fittings in which the length of the shortest
puncture path through solid insulating material is equal to or greater than one-third the external
arcing distance between the metal fittings
Design category B
Cylindrical post insulators with internal metal fittings in which the length of the shortest
puncture path through solid insulating material is less than one-third the external arcing
distance between the metal fittings
NOTE – The term “cylindrical insulators” is intended to cover insulators of the truncated conical form.

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60660 © IEC:1999 – 13 –
1.3.4
lot
group of insulators offered for acceptance from the same manufacturer, of the same design
and manufactured under similar conditions of production. 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
1.3.5
flashover
disruptive discharge external to the insulator, and over its surface, connecting those parts
which normally have the operating voltage between them. The term "flashover" used in this
standard includes flashover across the insulator surface as well as disruptive discharges by
sparkover through air adjacent to the insulator [IEV 471-01-12, modified]
1.3.6
puncture
a disruptive discharge passing through the solid insulating material of the insulator which
produces a permanent loss of dielectric strength
A fragment breaking away from the rim of a shed or damage to the insulator due to the heat of
the surface discharge is not considered as a puncture [IEV 471-01-11, modified]
1.3.7
dry lightning impulse withstand voltage
lightning impulse voltage which the dry post insulator withstands under the prescribed
conditions of test
1.3.8
50 % dry lightning impulse flashover voltage
value of the lightning impulse voltage which has a 50 % probability of producing flashover on
the dry post insulator under the prescribed conditions of test
1.3.9
dry power-frequency withstand voltage
power-frequency voltage which the dry post insulator withstands under the prescribed
conditions of test
1.3.10
dry power-frequency flashover voltage
arithmetic mean value of the measured voltages which cause flashover on the dry post
insulator under the prescribed conditions of test
1.3.11
mechanical failing load
maximum load reached when an organic insulator is tested under the prescribed conditions of
test
1.3.12
creepage distance
shortest distance along the contours of the external surfaces of the insulating parts of the post
insulator between those parts which normally have the operating voltage between them.
However, to take account of the metal fittings attached to the post insulator, the distance which
in service conditions is covered by metal fittings is not included in the creepage distance

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60660 © IEC:1999 – 15 –
NOTE 1 – If high-resistance coatings are applied to parts of the post insulators, such coatings are considered as
effective creepage surfaces and the distance over them is included in the creepage distance.
6
NOTE 2 – The surface resistivity of such high-resistance coatings is usually about 10 Ω but may be as low
4
as 10 Ω.
NOTE 3 – If high-resistance coatings are applied to the whole surface of the post insulator (the so-called
stabilized insulator), the questions of surface resistivity and creepage distance is subject to agreement between
the manufacturer and the purchaser.
NOTE 4 – The creepage distance is normally not specified.
1.3.13
specified characteristic
– either the numerical value of a voltage or of a mechanical load or of any other characteristic
specified in an IEC standard,
– or the numerical value of any such characteristic agreed between the manufacturer and
the purchaser
Specified withstand and flashover voltages are referred to standard atmospheric conditions
1.3.14
parallelism of the end faces
maximum difference in the height of the post insulator measured across the surface of the
metal fittings at each end
1.3.15
eccentricity
displacement, perpendicular to the axis of the post insulator, between the centres of the pitch
circles of the fixing holes in the top and bottom metal fittings
1.3.16
angular deviation of fixing holes
rotational displacement, expressed as an angle, between corresponding fixing holes in the
metal fittings at the top and bottom of a post insulator
1.4 Values which characterise a post insulator of organic material
A post insulator of organic material is characterised by the following values where applicable:
a) the specified dry lightning impulse withstand voltage;
b) the specified dry power-frequency withstand voltage;
c) the specified lightning impulse puncture voltage (for post insulators of design category B
only);
d) the specified mechanical failing loads;
e) the specified significant dimensions;
f) the maximum difference between the deflection at 20 % and 50 % of the specified mech-
anical failing load.
If requested, a design drawing of the post insulator shall be submitted.
NOTE 1 – Service voltage is not considered as a characteristic of a post insulator.
NOTE 2 – The withstand voltages of post insulators under service conditions may differ from the voltages under
standard testing conditions.

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60660 © IEC:1999 – 17 –
1.5 Documentation
1.5.1 Marking
Markings on each post insulator shall be the following:
– name and trade mark of the manufacturer;
– date of manufacture or serial number for insulators intended to be used for system voltages
72,5 kV and above. For lower voltages, only the year of manufacture is required;
– post insulator reference mark.
1.5.2 Records of insulators
The manufacturer shall maintain records of all produced insulators in accordance with this
standard for a minimum of 10 years. These records shall contain the following information:
– type reference number;
– date of manufacture or serial number for insulators intended to use for system voltages
72,5 kV and above. For lower voltages only the year of manufacture is required;
– type tests, date and results;
– sample tests, date and results;
– routine tests, date and results.
1.6 Normal service conditions
Normal temperature and relative humidity service conditions are defined as follows:
a) the ambient air temperature does not exceed 40 °C and its average value, measured over a
period of 24 h, does not exceed 35 °C;
b) the minimum ambient air temperature is –5 °C, –15 °C or –25 °C;
c) the altitude does not exceed 1 000 m;
d) the ambient air is not materially polluted by dust, smoke, corrosive or flammable gases and
vapours or salt;
e) the average value of the relative humidity, measured over a period of 24 h, does not
exceed 95 %;
f) the average value of the relative humidity, measured over a period of one month, does not
exceed 90 %;
NOTE – For these maximum relative humidity and temperature conditions of 95 % and 40 °C, respectively,
condensation occurs for a decrease in temperature of the post insulators of 1 °C.
2 General requirements for tests
2.1 Classification of tests
The tests are divided into three groups as follows:
a) Type tests
The type tests are intended to verify the main characteristics of a post insulator of organic
material, which depend mainly on its design, the material used and the manufacturing process.

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60660 © IEC:1999 – 19 –
They are usually carried out on one insulator, and once only for a new design or
manufacturing process, and then subsequently repeated only when the design, material or
manufacturing process is changed. When the change only affects certain characteristics,
only the test(s) relevant to those characteristics need to be repeated. For this, the type
tests are divided into three sub-groups according to their applicability (see 3.1).
Type tests shall be carried out only on insulators from a lot which meets the requirements
of all the relevant sample and routine tests not included in the type tests.
b) Sample tests
The sample tests are carried out to verify the characteristics of an insulator, which can vary
with the manufacturing process and the quality of the component materials of the insulator.
Sample tests are used as acceptance tests on a sample of post insulators, taken at random
from a lot which has met the requirements of the relevant routine tests.
c) Routine tests
The routine tests are intended to eliminate defective insulators and are carried out during
the manufacturing process. Routine tests are carried out on every insulator.
2.2 Quality assurance
A quality assurance programme, taking into account the requirements of this standard, can be
used, after agreement between the purchaser and the manufacturer, to verify the quality of the
insulators during the manufacturing process.
NOTE 1 – Detailed information on the use of quality assurance is given in ISO 9000-1.
ISO 9002 is recommended as a guide for quality system for insulators.
NOTE 2 – Certain well-established national standards for quality assurance programmes are also available.
2.3 General requirements for electrical tests
NOTE – Additional information related to subclauses 2.2 to 2.6 is given in IEC 60060-1.
a) Lightning impulse and power-frequency voltage test methods shall be in accordance
with IEC 60060-1.
b) Lightning impulse voltages shall be expressed by their prospective peak values. Power-
frequency voltages shall be expressed as peak values divided by 2 .
c) When the natural atmospheric conditions at the time of test differ from the standard values
(see 2.5), it is necessary to apply correction factors in accordance with 2.6.
d) The post insulators shall be clean and dry before starting the electrical tests.
e) Precautions shall be taken to avoid condensation on the surface of the post insulator,
especially when the relative humidity is high. For example, the post insulator shall be
maintained at the ambient temperature of the test location for sufficient time for thermal
equilibrium to be reached before the test starts. Except by agreement between the manu-
facturer and the purchaser, tests shall not be made if the relative humidity exceeds 85 %.

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60660 © IEC:1999 – 21 –
2.4 Lightning impulse voltage tests
The standard 1,2/50 lightning impulse shall be used (see IEC 60060-1) with the following
tolerances:
– peak value:  ±3 %;
– front time: ±30 %;
– time to half-value: ±20 %.
2.5 Power-frequency voltage tests
The test voltage shall be an alternating voltage having a frequency in the range 15 Hz to
100 Hz unless otherwise agreed between the manufacturer and the purchaser.
The test circuit shall be in accordance with IEC 60060-1.
2.6 Standard reference atmospheric conditions for tests
The standard reference atmospheric conditions for tests shall be in accordance with
IEC 60060-1:
– temperature: t = 20 °C;
o
– pressure: b = 101,3 kPa (1 013 mbar);
o
3
– absolute humidity: h = 11 g/m .
o
NOTE – A pressure of 101,3 kPa corresponds to a height of 760 mm in a mercury barometer at 0 °C. If the
barometer height is H mm of mercury, the atmospheric pressure in kilopascals is approximately:
b = 0,133 3 H kPa
Correction for temperature with respect to the height of the mercury column is considered to be negligible.
2.7 Correction factors for atmospheric conditions
The correction factors shall be determined in accordance with IEC 60060-1. If the atmospheric
conditions at the time of test differ from the standard reference atmosphere, then
the correction factors for air density (k ) and humidity (k ) shall be calculated, and the product
1 2
K = k ⋅ k determined. The test voltages shall then be corrected as follows:
1 2
– withstand voltages (lightning impulse and power frequency):
applied test voltage = K multiplied with the specified withstand voltage;
– flashover voltages (lightning impulse and power frequency):
recorded flashover voltage = measured flashover voltage divided by K.
3 Type tests
3.1 General
Normally, only one post insulator shall be subjected to each test (with the exception of the test
in 3.9). It shall be taken from a lot of insulators which meets the requirements of all the
relevant sample and routine tests. Insulators which have been submitted to type tests which
may affect their mechanical and/or electrical characteristics shall not be used in service.

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60660 © IEC:1999 – 23 –
Type tests on post insulators of the same organic material made by the same manufacturer
and manufacturing method are divided into three subgroups according to their applicability:
– tests related to the choice of material and the method of manufacture;
– tests related mainly to the choice of material and method of manufacture, but which may be
influenced by the design of the post insulator;
– tests related to the particular design of the post insulator.
For extreme service applications an alternative test procedure is recommended. Type testing
shall be carried out in a test sequence on one post insulator.
The relevant dimensions of the post insulator shall be verified according to the sample test
requirements (see 4.2).
3.1.1 Tests related to the choice of material and the method of manufacture
The following tests will normally be performed once only on a representative post insulator of
each material made by the same manufacturing method:
a) water absorption test (see 3.10);
b) flammability test (see 3.12);
c) ageing and humidity test (see 3.11).
NOTE – A tracking test should be considered when materials are selected for the manufacture of the insulator.
IEC 60587 may be applicable.
3.1.2 Tests related mainly to the choice of material and method of manufacture,
but which may be influenced by the design of the post insulator
The following test will normally be performed once only on insulators of similar shape and
dimensions which are within ±10 % of the original dimensions tested, made from the same
material by the same manufacturing method:
– test for mechanical bending strength as a function of temperature (see 3.9).
3.1.3 Tests related to the particular design of the post insulator
The following tests will be performed once only on each design of post insulator:
a) dry lightning impulse withstand voltage test (see 3.3);
b) dry power-frequency withstand voltage test (see 3.4);
c) lightning impulse puncture test (see 3.6);
d) temperature cycle test (see 3.13);
e) partial discharge extinction voltage test (see 3.5);
f) test for deflection under load at normal ambient temperature conditions (see 3.8);
g) mechanical failing load test (see 3.7).
3.1.4 Type tests to be applied in a test sequence for post insulators for
extreme service applications
Extreme service conditions are when the post insulator is subject either to high relative
humidity or to excessive condensation or pollution. The test sequence shall be made by
agreement between manufacturer and purchaser.

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60660 © IEC:1999 – 25 –
...