IEC 60587:2022

Electrical insulating materials used under severe ambient conditions - Test methods for evaluating resistance to tracking and erosion

IEC 60587:2022 describes two test methods for the evaluation of electrical insulating materials for use under severe ambient conditions at power frequencies (45 Hz to 65 Hz) by the evaluation of the resistance to tracking and erosion, using a liquid contaminant and inclined plane specimens. The two methods are:
- Method 1: test at constant voltage,
- Method 2: test at stepwise increased voltage.
Method 1 is the most widely used method as there is less need for continual inspection.
The test conditions are designed to accelerate the production of the effects, but do not reproduce all the conditions encountered in service.
This edition includes the following significant technical changes with respect to the previous edition:
a) an improved description of the experimental methods has been implemented;
b) an improved description of the preparation of the test specimens has been implemented;
c) a more detailed description of the electrode material and of the electrode quality has been added;
d) evaluation criterion B (track length) has been removed for testing according to test method 2 (stepwise tracking voltage) as it is not applicable.

Matériaux isolants électriques utilisés dans des conditions ambiantes sévères - Méthodes d'essai pour évaluer la résistance au cheminement et à l'érosion

L'IEC 60587:2022 décrit deux méthodes d'essai pour évaluer les matériaux isolants électriques utilisés dans des conditions ambiantes sévères à des fréquences industrielles (comprises entre 45 Hz et 65 Hz), qui reposent sur l'évaluation de la résistance au cheminement et à l'érosion, à l'aide d'un contaminant liquide et d'éprouvettes plates inclinées. Les deux méthodes sont les suivantes:
- Méthode 1: essai à tension constante;
- Méthode 2: essai avec augmentation de tension par paliers.
La méthode 1 est la plus couramment utilisée, car elle nécessite moins de contrôles en continu.
Les conditions d'essai sont conçues pour accélérer la manifestation des effets, mais elles ne reproduisent pas toutes les conditions rencontrées en service.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) une description améliorée des méthodes expérimentales a été établie;
b) une description améliorée de la préparation des éprouvettes a été établie;
c) une description plus détaillée du matériau et de la qualité des électrodes a été ajoutée;
d) le critère d'évaluation B (longueur de la trace de cheminement) a été supprimé pour les essais selon la méthode d'essai 2 (tension de cheminement par paliers), car il ne s'applique pas.

General Information

• Status: Published
• Publication Date: 29-Mar-2022
• ICS: 17.220.99 - Other standards related to electricity and magnetism
• ICS: 29.035.01 - Insulating materials in general
• Technical Committee: TC 112 - Evaluation and qualification of electrical insulating materials and systems
• Drafting Committee: WG 5 - TC 112/WG 5
• Current Stage: PPUB - Publication issued
• Start Date: 30-Mar-2022
• Completion Date: 29-Apr-2022

Relations

• Revises: IEC 60587:2007 - Electrical insulating materials used under severe ambient conditions - Test methods for evaluating resistance to tracking and erosion
• Effective Date: 05-Sep-2023

Overview

IEC 60587:2022 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies test methods for evaluating electrical insulating materials under severe ambient conditions. This standard focuses on assessing the material's resistance to tracking and erosion at power frequencies ranging from 45 Hz to 65 Hz. Tracking refers to the progressive formation of conductive paths on or within insulating materials due to electrical stress and contamination, while erosion covers the electrical loss of material by leakage current or electrical discharge.

The standard outlines two primary test methods using inclined plane specimens contaminated with liquid to simulate harsh environmental conditions:

• Method 1: Testing at constant voltage, the more widely adopted method due to reduced need for continuous monitoring.
• Method 2: Testing with stepwise increased voltage.

IEC 60587:2022 provides an enhanced and detailed approach compared to previous editions, including improved specimen preparation, electrode material descriptions, and modifications in evaluation criteria.

Key Topics

• Test Methods for Resistance Evaluation
  The two methods in IEC 60587 utilize inclined plane specimens wetted with a liquid contaminant to accelerate tracking and erosion phenomena.

  • Method 1 (Constant Voltage): Applies a continuous voltage to the specimen, monitoring the resistance to tracking over time.
  • Method 2 (Stepwise Voltage Increase): Involves incrementally raising the voltage in steps, designed for detailed voltage endurance assessment but requires more intensive inspection.

• Specimen Preparation and Dimensions
  Specimens are flat, sized at least 50 mm by 120 mm, with a preferred thickness of 6 mm, and include boreholes for electrode mounting. Proper cleaning with solvents and rinsing with distilled water is mandatory to avoid residual contamination affecting results.

• Electrode and Apparatus Requirements
  Detailed specifications for electrode material, surface quality, and assembly ensure repeatable conditions. The test setup includes a filter-paper stack to simulate contamination and apparatus to maintain constant or stepwise applied voltages and environmental controls like ventilation.

• Evaluation Criteria
  Method 1 measures leakage current and visually inspects erosion, while Method 2’s evaluation no longer includes track length (criterion B), focusing instead on voltage endurance and current flow.

• Accelerated Aging but Real-World Limitations
  The test accelerates the effects of tracking and erosion for timely assessment but does not reproduce all service conditions a material might experience in actual installations.

Applications

IEC 60587:2022 is indispensable for manufacturers, researchers, and quality assurance professionals involved in the development and qualification of electrical insulating materials used in demanding environments. Typical applications include:

• Power Industry
  Insulating materials for equipment exposed to humid, contaminated, or polluted environments where high voltage tracking and erosion risks are significant.

• Electrical Component Testing
  Routine qualification and validation of insulators, bushings, cable jacketing, and other insulating products intended for outdoor or industrial use.

• Material Research and Development
  Establishing baseline resistance levels and enhancing the performance of novel insulating materials.

• Safety and Compliance
  Ensuring products meet internationally recognized performance criteria to prevent failures related to electrical tracking and material degradation.

Related Standards

Relevant to IEC 60587:2022 are other IEC and ISO standards focused on electrical insulation and testing, including:

• IEC 60050-212:2010 – International Electrotechnical Vocabulary chapter related to tracking and erosion terms.
• IEC 60216 – Electrical insulating materials - Thermal endurance properties and classification.
• IEC 61109 – Insulated cables for electricity supply – Test methods for resistance to tracking and erosion of cable materials.
• ISO/IEC Directives – Framework guiding the development and publication of international standards.

By aligning with IEC 60587:2022, stakeholders can ensure global consistency in testing methods and material performance evaluation under severe ambient conditions, enhancing reliability and safety of electrical insulating products.

---

Keywords: IEC 60587:2022, electrical insulating materials, tracking resistance test, erosion evaluation, inclined plane test, power frequency testing, severe ambient conditions, electrical insulation testing, IEC standards, electrical equipment reliability.

Standards Content (Sample)

IEC 60587 ®
Edition 4.0 2022-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical insulating materials used under severe ambient conditions –
Test methods for evaluating resistance to tracking and erosion

Matériaux isolants électriques utilisés dans des conditions ambiantes sévères –
Méthodes d'essai pour évaluer la résistance au cheminement et à l'érosion

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IEC 60587 ®
Edition 4.0 2022-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electrical insulating materials used under severe ambient conditions –

Test methods for evaluating resistance to tracking and erosion

Matériaux isolants électriques utilisés dans des conditions ambiantes sévères –

Méthodes d'essai pour évaluer la résistance au cheminement et à l'érosion

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.99; 29.035.01 ISBN 978-2-8322-1093-8

– 2 – IEC 60587:2022 © IEC 2022
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test specimens . 6
4.1 Dimensions . 6
4.2 Preparation . 6
5 Apparatus . 7
5.1 General . 7
5.2 Electrical apparatus . 7
5.3 Specimen assembly . 8
5.3.1 General . 8
5.3.2 Electrodes . 9
5.3.3 Filter-paper stack . 10
5.3.4 Mounting of the specimen assembly . 11
5.4 Contaminant . 13
5.5 Timing device . 13
5.6 Depth gauge . 13
5.7 Ventilation. 14
6 Test procedure . 14
6.1 General . 14
6.2 Criterion A – evaluation of the current (preferred) . 14
6.3 Criterion B – evaluation of the length of the track . 14
6.4 Method 1 – test at constant voltage. 14
6.5 Method 2 – test at stepwise increased voltage . 15
6.6 Classification of the materials tested according to method 1 . 16
6.7 Classification of the materials tested according to method 2 . 16
7 Test report . 17
Bibliography . 18

Figure 1 – Test specimen with boreholes for mounting of electrodes . 6
Figure 2 – Schematic diagram of circuit . 8
Figure 3 – Example of typical circuit for an overcurrent delay relay (ODR) . 8
Figure 4 – Schematic diagram of specimen assembly . 9
Figure 5 – Top electrode . 10
Figure 6 – Bottom electrode . 10
Figure 7 – Filter-paper . 11
Figure 8 – Schematic diagram of specimen assembly . 11
Figure 9 – Schematic diagram of specimen support . 12
Figure 10 – Example of specimen support. 13

Table 1 – Specimen preparation sequence . 7
Table 2 – Test parameters . 15

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSULATING MATERIALS USED
UNDER SEVERE AMBIENT CONDITIONS – TEST METHODS
FOR EVALUATING RESISTANCE TO TRACKING AND EROSION

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 60587 has been prepared by IEC technical committee 112: Evaluation and qualification of
electrical insulating materials and systems. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2007. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) an improved description of the experimental methods has been implemented;
b) an improved description of the preparation of the test specimens has been implemented;
c) a more detailed description of the electrode material and of the electrode quality has been
added;
d) evaluation criterion B (track length) has been removed for testing according to test method 2
(stepwise tracking voltage) as it is not applicable.

– 4 – IEC 60587:2022 © IEC 2022
The text of this International Standard is based on the following documents:
Draft Report on voting
112/561/FDIS 112/564/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
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ELECTRICAL INSULATING MATERIALS USED
UNDER SEVERE AMBIENT CONDITIONS – TEST METHODS
FOR EVALUATING RESISTANCE TO TRACKING AND EROSION

1 Scope
This document describes two test methods for the evaluation of electrical insulating materials
for use under severe ambient conditions at power frequencies (45 Hz to 65 Hz) by the
evaluation of the resistance to tracking and erosion, using a liquid contaminant and inclined
plane specimens. The two methods are:
– Method 1: test at constant voltage,
– Method 2: test at stepwise increased voltage.
Method 1 is the most widely used method as there is less need for continual inspection.
The test conditions are designed to accelerate the production of the effects, but do not
reproduce all the conditions encountered in service.
2 Normative references
There are no normative references in this document.
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
track
partially conducting path created by localized deterioration on the surface of an insulating
material
3.2
tracking
progressive formation of conductive paths, which are produced on the surface or within a solid
insulating material, due to the combined effects of electric stress and electrolytic contamination
Note 1 to entry: Tracking usually occurs due to surface contamination.
Note 2 to entry: Remaining degraded materials need not necessarily remain conductive, especially after they have
cooled.
[SOURCE: IEC 60050-212:2010, 212-11-56, modified – Note 2 to entry has been added.]
3.3
erosion
electrical loss of material by leakage current or electrical discharge

– 6 – IEC 60587:2022 © IEC 2022
4 Test specimens
4.1 Dimensions
Flat specimens with a size of at least (50 × 120) mm shall be used. The preferred thickness
should be 6 mm. Specimens with a different thickness may be used. Thickness shall be
mentioned in the test report.
Dimensions in millimetres
Figure 1 – Test specimen with boreholes for mounting of electrodes
4.2 Preparation
The mechanical processing of the test specimens is as shown in Figure 1, to allow the
attachment of electrodes.
The specimens shall be washed with a suitable solvent (e.g. isopropyl alcohol) to remove
leftovers such as fatty residues from preparation and handling. The specimens shall then be
rinsed with distilled water.
Specimens used for evaluation with criterion B (see Clause 6) shall be marked with reference
marks on both long sides 25 mm above the upper edge of the lower electrode (Figure 1 and
Figure 8). Unless otherwise specified, the test specimens shall be conditioned for a minimum
of 24 h at (23 ± 2) °C, with (50 ± 10) % RH.
When mounting the cleaned and conditioned specimens, ensure they are not contaminated.
Good wettability of the specimen surface with the contaminant (see 5.4) is a crucial prerequisite
for this test method. The wettability shall be evaluated beforehand. If the contaminant does not
wet the surface, the specimens can be slightly abraded. Grinding should be done with a fine
(U.S. grade (CAMI): 400 mesh; European grade (FEPA): P800) aluminium-oxide- or zirconia-
alumina-abrasive, under water, until the whole surface wets. Specimens shall be properly rinsed
with distilled water after grinding. Grinding or any other type of changes of the surface shall be
mentioned in the test report.
An alternative to grinding is to increase the flow rate, temporarily, until the specimen’s surface
is properly wetted prior to switching on the test voltage.

The specimen preparation sequence is shown in Table 1.
Table 1 – Specimen preparation sequence
Step Activity
1 Mechanical processing
2 Cleaning
3 Marking if necessary
4 Conditioning
5 Mounting
6 Checking of the wettability
6.1 Improving wettability if necessary (either by grinding or by temporarily increasing the flow rate)
6.2 Rinsing with distilled water if the test specimens have been grinded followed by step 5

5 Apparatus
5.1 General
The test apparatus consists of the electrical apparatus and the specimen assemblies. These
contain a specimen each, optionally with a mounting support, the electrodes and the filter-paper
pad for feeding the contaminant.
5.2 Electrical apparatus
A schematic circuit diagram is given in Figure 2. As the test will be carried out at high voltage,
it is obviously necessary to use an earthed safety enclosure. The circuit comprises:
– a (45 to 65) Hz power supply with a sinusoidal voltage with total harmonic distortion of ≤ 5 %
and a crest factor of √2 (1 ± 0,05) which can be varied up to about 6 kV at a rated current not
less than 0,1 A for each specimen;
– the output voltage that shall be stabilized to ±5 % at rated current;
– a true RMS voltmeter with an accuracy of 1,5 % of reading;
– a 200 W resistor with ±10 % tolerance in series with each specimen at the high-voltage side
of the power supply. The resistance of the resistor shall be taken from Table 2;
– an overcurrent delay relay (see Figure 3) or any other device in series with each specimen,
which operates when (60 ± 6) mA has persisted in the high-voltage circuit for (3 ± 1) s.
If only one power supply is used for several specimens, each shall have a circuit-breaker or
similar device. This is to ensure that failures of a single specimen do not lead to a switch-off of
the test-voltage of all other specimens.

– 8 – IEC 60587:2022 © IEC 2022

Key
S Power supply switch
VT Variable ratio transformer
T High voltage transformer
R Series resistor
V Voltmeter
Sp Specimen
ODR Overcurrent delay relay
Figure 2 – Schematic diagram of circuit

Key
Re Rectifier
Tr Transformer (winding 300/900 turns)
RI Relay (2 500 Ω/11 000 turns)
C Capacitor (200 µF)
Figure 3 – Example of typical circuit for an overcurrent delay relay (ODR)
5.3 Specimen assembly
5.3.1 General
A specimen assembly consists of (Figure 4):
– the test specimen, optionally with a mounting support,
– the electrodes with accessories such as screws, washers and nuts,
– a filter-paper stack for feeding the contaminant,
– a mounting.
All electrodes, fixtures and metallic assembly elements associated with the electrodes, such as
screws, shall be made of stainless steel, preferably of type 302 (18 % chromium, 8 % nickel
austenitic alloy).
Dimensions in millimetres
Figure 4 – Schematic diagram of specimen assembly
5.3.2 Electrodes
Electrodes shall be made of stainless steel, preferably of type 302 (18 % chromium, 8 % nickel
austenitic alloy). The thickness of the electrode material shall be 0,5 mm. The top electrode is
shown in Figure 5. The bottom electrode is shown in Figure 6.
New electrodes shall be used for each test. For screening testing, used and reworked
electrodes can be utilized. The edges of the electrodes, especially those oriented towards the
stressed area of the specimen between the electrodes, shall be well deburred.

– 10 – IEC 60587:2022 © IEC 2022
Dimensions in millimetres
Figure 5 – Top electrode
Dimensions in millimetres
Figure 6 – Bottom electrode
5.3.3 Filter-paper stack
Eight layers of filter-paper with a thickness of (0,2 ± 0,02) mm, of the approximate dimensions
given in Figure 7, are clamped between the top electrode and the specimen to act as a reservoir
for the contaminant.
Dimensions in millimetres
Figure 7 – Filter-paper
5.3.4 Mounting of the specimen assembly
Mount the specimen with the surface that is to be exposed to the contaminant towards the lower
side of the specimen assembly, at an angle of (45 ± 2)° from the horizontal as shown in Figure 8,
with the electrodes (50 ± 0,5) mm apart.
Dimensions in millimetres
Figure 8 – Schematic diagram of specimen assembly

– 12 – IEC 60587:2022 © IEC 2022
The electrodes shall be mounted in such a way that there is neither a gap between the electrode
edges at the test specimen nor a deformation of the specimen surface.
The filter-paper stack acts as a reservoir for the contaminant as shown in Figure 8. The
mounting screws and the V-shaped cuts give the position of the sheets. For each test, use a
new filter-paper stack (see Figure 9). If the specimen is not self-supporting, an insulating
specimen support for the specimen shall be used. The specimen support shall be such that the
heat dissipation from the back of the sample is not hindered and the material shall be heat
resistant and electrically insulating (e.g. polytetrafluoroethylene). Figure 9 and Figure 10 show
a sketch and an example of a specimen support respectively.
Dimensions in millimetres
Figure 9 – Schematic diagram of specimen support

Figure 10 – Example of specimen support
5.4 Contaminant
Unless otherwise specified use a contaminant with a conductivity at (23 ± 1) °C of (0,256 41 to
0,25) S/m, which can be achieved by adding approximately 0,1 % by mass of NH Cl (ammonium
chloride), consisting of
– distilled or de-ionized water and NH Cl (ammonium chloride) of analytical quality, and
– (0,02 ± 0,002) % by mass of the non-ionic wetting agent octylphenoxypolyethoxy-ethanol
(CAS number: 9002-93-1).
The contaminant shall be not more than four weeks old and its conductivity shall be checked
before each series of tests.
The rate of application of contaminant shall be that specified in Table 2, within ±10 % in relation
to the applied voltage. This is usually done by pumping the contaminant through a tube and let
it drop onto the filter-paper stack.
The contaminant shall be fed into the filter-paper stack so that a uniform flow between the top
and the bottom electrodes shall occur before voltage application.
Feeding of the contaminant onto the filter-paper stack shall be done in such a way that the
contaminant in neither the tube/reservoir, nor the feeding/pumping device is exposed to the
high voltage of the top electrode.
5.5 Timing device
A timing device with an accuracy of ±1 min/h shall be used.
5.6 Depth gauge
A depth gauge with an accuracy of ±0,01 mm shall be used. The point of the probe shall be
hemispherical with a radius of 0,25 mm. The weight of the gauge shall not have an influence
on the measuring result.
– 14 – IEC 60587:2022 © IEC 2022
5.7 Ventilation
The test stand or the test chamber shall allow an exhaust of steam and gaseous decomposition
products in order to avoid both condensation of steam and contamination of the surrounded
volume. Experience shows that the intensity of ventilation may influence the test result.
Especially a direct airflow onto the surface of the specimens shall be avoided.
6 Test procedure
6.1 General
Unless otherwise specified, the test shall be carried out at an ambient temperature of
(23 ± 2) °C using sets of at least five specimens for each material.
Prepare the specimen assemblies.
Mount the specimen assemblies in the test stand or test chamber.
Adjust the settings of the electrical apparatus (voltage, contaminant flow rate and series
resistor), (Table 2), depending on the chosen test voltage.
Select a criterion for determining the end point of the test. The following criteria for determining
the end point of the test are applicable.
6.2 Criterion A – evaluation of the current (preferred)
The end point of the test of a specimen is reached when the value of the current in the high
voltage circuit through the specimen exceeds 60 mA (an overcurrent device then breaks this
current not before 2 s, but after 4 s latest).
This criterion permits the use of an automatic apparatus testing several specimens
simultaneously.
Any specimen that ignites during the test counts as "failed" as well.
Any specimen that shows a hole (perforation) due to erosion counts as "failed", no matter
whether the hole becomes visible during the test or after the removal of the eroded material.
6.3 Criterion B – evaluation of the length of the track
The end point is reached when the track reaches a mark on the specimen surface 25 mm from
the lower electrode.
This end point criterion (criterion B) requires constant visual supervision and manual control.
Any specimen that ignites during the test counts as "failed" as well.
Any specimen that shows a hole (perforation) due to erosion counts as "failed", no matter
whether the hole becomes visible during the test or after the removal of the eroded material.
Select the test method. Two methods are applicable (see 6.4 and 6.5).
6.4 Method 1 – test at constant voltage
A test voltage is selected (Table 2) and kept stable for the test time of 6 h.

Table 2 – Test parameters
Preferred test voltage for Series resistor,
Test voltage Contaminant flow rate
method 1 Resistance
kV kV ml/min kΩ
1,0 to 1,75 – 0,075 1
2,0 to 2,75 2,5 0,15 10
3,0 to 3,75 3,5 0,30 22
4,0 to 4,75 4,5 0,60 33
5,0 to 6,0 – 0,90 33
The number of test specimens is five (initial set of specimens). Specimens can be tested
simultaneously or subsequently. If none of the specimens fails, the result is "pass".
If one of the five specimens fails at a certain test voltage, an additional set of five samples shall
be tested (extended set of specimens). If only one of the total of 10 specimens fails, the result
is "pass".
6.5 Method 2 – test at stepwise increased voltage
A starting voltage, being a multiple of 250 V, is selected such that failure according to criterion
A does not occur sooner than the third voltage step (a preliminary trial test may be necessary).
Maintain this voltage for 1 h and increase the voltage by steps of 250 V for each subsequent
hour until failure by criterion A is recorded. As the voltage is increased the contaminant flow
rate and the resistance value of the series resistor are increased according to the values
specified in Table 2.
Start introducing the contaminant into the filter-paper stack allowing the contaminant to wet the
paper thoroughly. Adjust the contaminant flow and calibrate to give a flow rate as specified in
Table 2. Observe the flow for at least 10 min and ensure that the contaminant flows steadily
down the face of the test specimen between the electrodes. The contaminant shall flow from
the quill hole of the top electrode and not from the sides or the top of the filter-paper.
If a constant flow rate of the contaminant is reached, the test voltage can be applied according
to test method 1 or 2.
As soon as the voltage is applied there will be current through the path of the electrolyte. The
current will lead to scintillation close to the bottom electrode. Scintillation means the existence
of small yellow to white (with some materials occasionally blue) arcs just above the teeth of the
lower electrode, within a few minutes of application of the voltage. These discharges should
occur in an essentially continuous manner, although they may jump from one tooth to another.
Discharges will lead to the formation of electrical erosion and/or the formation of tracking,
depending on the ability of the tested material to withstand these stresses.
Effective scintillation is essential and if not obtained, the electrical circuit, the contaminant flow
characteristics and contaminant conductivity should be carefully checked (scintillation activity
may also be observed by means of an oscilloscope and/or a frequency analyser). The signal
may be picked up across a resistor (e.g. 330 Ω, 2 W) placed in series with the overcurrent
device. Proper scintillation is observed as a continual, but non-uniform, break-up of the power
frequency current wave during each half cycle.
Failed specimen assemblies or those that withstood for 6 h are removed from the test stand
and dismantled for investigation. Measure the erosion depth after removing decomposed
insulation and debris, taking care not to remove any undamaged test material.

– 16 – IEC 60587:2022 © IEC 2022
If the test has to be repeated at a higher or lower voltage, a further set of new specimens shall
be tested for each selected voltage.
6.6 Classification of the materials tested according to method 1
Testing at one of the preferred test voltages allows classification as follows. The classification
represents the highest voltage of the preferred test voltages that the material has withstood.
a) as per criterion A
Class 1A 4,5
– if all specimens of the initial set pass 6 h at 4,5 kV or
– if 9 of 10 specimens of the extended set pass 6 h at 4,5 kV.
Class 1A 3,5
– if all specimens of the initial set pass 6 h at 3,5 kV or
– if 9 of 10 specimens of the extended set pass 6 h at 3,5 kV.
Class 1A 2,5
– if all specimens of the initial set pass 6 h at 2,5 kV or
– if 9 of 10 specimens of the extended set pass 6 h at 2,5 kV.
Class1A 0
if more than one specimen out of a total of 10 fails at 2,5 kV in less than 6 h.
b) as per criterion B
Class 1B 4,5
– if all specimens of the initial set pass 6 h at 4,5 kV or
– if 9 of 10 specimens of the extended set pass 6 h at 4,5 kV.
Class 1B 3,5
– if all specimens of the initial set pass 6 h at 3,5 kV or
– if 9 of 10 specimens of the extended set pass 6 h at 3,5 kV.
Class 1B 2,5
– if all specimens of the initial set pass 6 h at 2,5 kV or
– if 9 of 10 specimens of the extended set pass 6 h at 2,5 kV.
Class1B 0
if more than one specimen out of a total of 10 fails at 2,5 kV in less than 6 h.
6.7 Classification of the materials tested according to method 2
The withstand voltage is the voltage step withstood by all five specimens for 1 h without
reaching the end point criterion A and without igniting or forming a hole (perforation).
Classification of the material is as follows:
Class 2A x
where x is the highest voltage, in kilovolts, withstood by the material under test.

7 Test report
The report shall include:
a) type and designation of material tested;
b) details of the specimens such like:
– fabrication,
– dimensions,
– cleaning procedure and solvent used,
– surface treatment if any,
– pre-conditioning;
c) orientation of composite specimen (like fibre reinforced plastic) with respect to the
electrodes (i.e. machine direction, cross-machine direction, bias, etc.);
d) test method, test voltage and end point criterion applied;
e) test results for each specimen;
f) classification of the material;
g) the maximum depth of erosion to be reported in the classification. For example, a maximum
erosion depth of 0,5 mm as "1 A 3,5 – 0,5".

– 18 – IEC 60587:2022 © IEC 2022
Bibliography
IEC 60050-212, International Electrotechnical Vocabulary (IEV) – Part 212: Electrical insulating
solids, liquids and gases (available at http://www.electropedia.org)

___________
– 20 – IEC 60587:2022 © IEC 2022
SOMMAIRE
AVANT-PROPOS . 21
1 Domaine d'application . 23
2 Références normatives . 23
3 Termes et définitions . 23
4 Éprouvettes . 24
4.1 Dimensions . 24
4.2 Préparation . 24
5 Appareillage . 25
5.1 Généralités . 25
5.2 Appareillage électrique . 25
5.3 Assemblage d'éprouvette . 26
5.3.1 Généralités . 26
5.3.2 Électrodes . 27
5.3.3 Tampons de papier filtre . 28
5.3.4 Montage de l'assemblage d'éprouvette . 29
5.4 Contaminant . 31
5.5 Dispositif de mesure du temps . 31
5.6 Jauge de profondeur . 31
5.7 Ventilation. 32
6 Procédure d'essai . 32
6.1 Généralités . 32
6.2 Critère A – évaluation du courant (privilégié) . 32
6.3 Critère B – évaluation de la longueur de la trace de cheminement . 32
6.4 Méthode 1 – essai à tension constante . 33
6.5 Méthode 2 – essai avec augmentation de tension par paliers . 33
6.6 Classification des matériaux soumis à l'essai selon la méthode 1 . 34
6.7 Classification des matériaux soumis à l'essai selon la méthode 2 . 35
7 Rapport d'essai . 35
Bibliographie . 36

Figure 1 – Eprouvette à trous pour le montage d'électrodes . 24
Figure 2 – Schéma de circuit . 26
Figure 3 – Exemple de circuit type pour un relais temporisateur de surintensité (ODR,
Overcurrent Delay Relay) . 26
Figure 4 – Schéma d'assemblage d'éprouvette . 27
Figure 5 – Electrode supérieure . 28
Figure 6 – Electrode inférieure . 28
Figure 7 – Papier filtre . 29
Figure 8 – Schéma de l'assemblage d'éprouvette . 29
Figure 9 – Schéma de support d'éprouvette . 30
Figure 10 – Exemple de support d'éprouvette . 31

Tableau 1 – Séquence de préparation des éprouvettes . 25
Tableau 2 – Paramètres d'essai . 33

COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
MATÉRIAUX ISOLANTS ÉLECTRIQUES
UTILISÉS DANS DES CONDITIONS AMBIANTES SÉVÈRES –
MÉTHODES D'ESSAI POUR ÉVALUER LA RÉSISTANCE
AU CHEMINEMENT ET À L'ÉROSION
AVANT-PROPOS
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...