IEC TS 62561-8:2018

IEC TS 62561-8 ®
Edition 1.0 2018-01
TECHNICAL
SPECIFICATION
SPECIFICATION
TECHNIQUE
Lightning protection system components (LPSC) –
Part 8: Requirements for components for isolated LPS

Composants de système de protection contre la foudre (CSPF) –
Partie 8: Exigences pour les composants de système isolé de protection contre
la foudre
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IEC TS 62561-8 ®
Edition 1.0 2018-01
TECHNICAL
SPECIFICATION
SPECIFICATION
TECHNIQUE
Lightning protection system components (LPSC) –

Part 8: Requirements for components for isolated LPS

Composants de système de protection contre la foudre (CSPF) –

Partie 8: Exigences pour les composants de système isolé de protection contre

la foudre
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.020; 91.120.40 ISBN 978-2-8322-5355-7

– 2 – IEC TS 62561-8:2018 © IEC 2018
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Insulating stand-off . 9
4.1 Classification . 9
4.1.1 General . 9
4.1.2 According to conductor clamping arrangement . 10
4.1.3 According to mounting . 10
4.2 Requirements . 10
4.2.1 General . 10
4.2.2 Construction . 10
4.2.3 Mechanical requirements . 10
4.2.4 Electrical requirements . 12
4.2.5 Documentation . 13
4.2.6 Marking . 13
4.3 Tests . 13
4.3.1 General test conditions . 13
4.3.2 General test setup . 16
4.3.3 Documentation . 17
4.3.4 Marking test . 17
4.3.5 Environmental influence tests . 17
4.3.6 Mechanical tests . 18
4.3.7 Electrical test . 23
4.4 Electromagnetic compatibility (EMC) . 24
4.5 Structure and content of the test report . 24
4.5.1 General . 24
4.5.2 Report identification . 25
4.5.3 Specimen description . 25
4.5.4 Characterization and condition of the test specimen and/or test

assembly . 25
5 Insulating down-conductor . 26
5.1 Classification . 26
5.2 Lightning current carrying capability . 27
5.3 Preferred values of equivalent separation distance s . 27
e
5.4 Requirements . 27
5.4.1 General . 27
5.4.2 Environmental requirements . 27
5.4.3 Mechanical requirements . 28
5.4.4 Electrical requirements . 28
5.4.5 Documentation . 28
5.4.6 Marking . 29
5.5 Tests . 29
5.5.1 General test conditions . 29
5.5.2 General test setup . 30
5.5.3 Documentation . 30
5.5.4 Marking test . 31

5.5.5 Environmental influence tests . 31
5.5.6 Mechanical tests . 32
5.5.7 Electrical tests . 36
5.6 Electromagnetic compatibility (EMC) . 41
5.7 Structure and content of the test report . 41
5.7.1 General . 41
5.7.2 Report identification . 41
5.7.3 Specimen description . 42
5.7.4 Characterization and condition of the test specimen and/or test
assembly . 42
5.7.5 Insulating down-conductor . 42
5.7.6 Standards and references . 42
5.7.7 Testing equipment, description . 42
5.7.8 Measuring instruments description . 43
5.7.9 Results and parameters recorded . 43
Annex A (normative) Environmental test – corrosion resistance . 44
A.1 General . 44
A.2 Salt mist test . 44
A.3 Humid sulphurous atmosphere test . 44
A.4 Ammonia atmosphere test . 44
Annex B (normative) Environmental test – resistance to ultraviolet light . 45
B.1 General . 45
B.2 The test . 45
B.3 First alternative test to B.2 . 45
B.4 Second alternative test to B.2 . 45
Annex C (normative) Flow chart of tests for insulating stand-offs . 46
Annex D (normative) Flow chart of tests for insulating down-conductors . 47
Annex E (informative) High voltage impulse test to determine the actual correction
factor k for insulating stand-offs . 48
x
E.1 Specimen preparation . 48
E.2 Test setup . 48
E.3 Test procedure . 49
Annex F (informative) Installation arrangement test to determine the influence of
supporting structures on the separation distance . 50
F.1 Specimen preparation for the high voltage installation arrangement test . 50
F.2 Test procedure . 50
Bibliography . 52

Figure 1 – Typical insulating stand-off with a metallic fastener . 11
Figure 2 – Typical insulating stand-off with a non-metallic fastener . 12
Figure 3 – Typical insulating stand-off with a metallic fastener prepared for testing. 14
Figure 4 – Typical insulating stand-off with a non-metallic fastener prepared for testing. 15
Figure 5 – Basic arrangement for bending test . 19
Figure 6 – Pendulum hammer test apparatus . 20
Figure 7 – Basic arrangement for pull out test on rigidly fixed insulating stand-off . 21
Figure 8 – Basic arrangement for pull out test on free standing insulating stand-off . 22
Figure 9 – General description of the test arrangement for the high voltage impulse
test of an insulating stand-off . 23

– 4 – IEC TS 62561-8:2018 © IEC 2018
Figure 10 – Specimen preparation for UV light test . 32
Figure 11 – Basic arrangement for lateral load test . 33
Figure 12 – Typical arrangement for axial movement test . 34
Figure 13 – Basic arrangement for the lightning current carrying capability test . 37
Figure 14 – General description of the test setup for the high voltage impulse test of
the insulating down-conductor. 38
Figure 15 – Test arrangement for insulating down-conductors. 39
Figure 16 – Test arrangement for partial insulating down-conductors . 40
Figure C.1 – Tests for insulating stand-offs . 46
Figure D.1 – Tests for insulating down-conductors . 47
Figure E.1 – General description of the test arrangement to determine the actual
correction factor k for insulating stand-offs . 48
x
Figure F.1 – Example for installation arrangement test – specimen under test . 50

Table 1 – Type test requirements for an insulating stand-off . 16
Table 2 – Lightning impulse current (I ) parameters . 27
imp
Table 3 – Type test requirements for an insulating down-conductor and fasteners . 30

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LIGHTNING PROTECTION SYSTEM COMPONENTS (LPSC) –

Part 8: Requirements for components for isolated LPS

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
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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.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a Technical
Specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical Specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 62561-8, which is a Technical Specification, has been prepared by IEC technical
committee 81: Lightning protection.

– 6 – IEC TS 62561-8:2018 © IEC 2018
A list of all parts in the IEC 62561 series, published under the general title Lightning
protection system components (LPSC), can be found on the IEC website.
This bilingual version (2018-02) corresponds to the monolingual English version, published in
2018-01.
The text of this Technical Specification is based on the following documents:
Enquiry draft Report on voting
81/562/DTS 81/574/RVDTS
Full information on the voting for the approval of this Technical Specification can be found in
the report on voting indicated in the above table.
The French version of this standard has not been voted upon.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• transformed into an International Standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
LIGHTNING PROTECTION SYSTEM COMPONENTS (LPSC) –

Part 8: Requirements for components for isolated LPS

1 Scope
This document specifies the requirements and tests for insulating stand-offs, used in
conjunction with an air-termination system and down-conductors with the aim of maintaining
the proper separation distance, and the requirements and tests for insulating
down-conductors, including their specific fasteners, able to reduce the separation distance.
Testing of insulating stand-offs and insulating down-conductors components for an explosive
atmosphere is not covered by this document.
Requirements and tests for other types of components for isolated LPS are under
consideration.
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 60060-2:2010, High-voltage test techniques – Part 2: Measuring systems
IEC 60068-2-52:2017, Environmental testing – Part 2: Tests – Test Kb: Salt mist, cyclic
(sodium chloride solution)
IEC 60068-2-75:2014, Environmental testing – Part 2:Tests – Test Eh: Hammer tests
IEC 61083-1, Instruments and software used for measurement in high-voltage impulse tests –
Part 1: Requirements for instruments
IEC 61083-2, Instruments and software used for measurement in high-voltage and high-
current tests – Part 2: Requirements for software for tests with impulse voltages and currents
IEC 62305-3, Protection against lightning – Part 3: Physical damage to structures and life
hazard
IEC 62561-1:2017, Lightning protection system components (LPSC) – Part 1: Requirements
for connection components
IEC 62561-2:2012, Lightning protection system components (LPSC) – Part 2: Requirements
for conductors and earth electrodes
IEC 62561-4, Lightning protection system components (LPSC) – Part 4: Requirements for
conductor fasteners
ISO 4892-2, Plastics – Methods of exposure to laboratory light sources – Part 2: Xenon-arc
lamps
– 8 – IEC TS 62561-8:2018 © IEC 2018
ISO 4892-3:2016, Plastics – Methods of exposure to laboratory light sources – Part 3:
Fluorescent UV lamps
ISO 4892-4, Plastics – Methods of exposure to laboratory light sources – Part 4: Open-flame
carbon-arc lamps
ISO 6988:1985, Metallic and other non-organic coatings – Sulfur dioxide test with general
condensation of moisture
ISO 6957:1988, Copper alloys – Ammonia test for stress corrosion resistance
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
insulating stand-off
non-metallic or composite component, consisting of the insulator and fixation parts, designed
to retain, support and insulate the air-termination system and/or down-conductors at a
required separation distance
3.2
effective length correction factor
k
x
factor evaluating the different withstand voltage of air gaps and insulators under test voltages
and environmental influences like pollution and/or UV light degradation
3.3
steepness correction factor for insulating stand-offs
c
is_st
factor considering the effect of higher steepness and the probability of occurrence of
subsequent negative short strokes on the flashover voltage of an insulating stand-off
Note 1 to entry: The value is defined in the test procedure.
3.4
effective length of an insulating stand-off
l
eff
length (distance) of an air gap with equivalent break down behaviour to an insulating stand-off
3.5
corrected distance value of an insulating stand-off
l
st
shortest measured clearance distance between two conductive elements of different electrical
potential, e.g. between a metallic conductor fastener and a mounting assembly
3.6
equivalent separation distance
s
e
corrected distance value to be used instead of the insulating length of a stand-off distance
value equivalent to the separation distance of conventional down-conductors required in
IEC 62305-3
3.7
down-conductor
conductor made of bare metal
3.8
insulating down-conductor
conductor provided with a layer of insulation with the purpose to reduce the separation
distance
3.9
steepness correction factor for insulating down-conductors
c
dc_st
factor considering the effect of higher steepness and the probability of occurrence of
subsequent negative short strokes on the withstand voltage of insulating down-conductors
during testing
Note 1 to entry: The value is defined in the test procedure.
3.10
partial insulating down-conductor
conductor provided with a layer of insulation with the purpose to reduce the separation
distance, supported by insulating stand-offs
3.11
clearance of the comparison arrangement
s
c
gap distance of the comparison arrangement used for verification of the effective length
correction factor k and separation distance s
x e
3.12
time to chopping
T
c
virtual parameter defined as the interval between the virtual origin and the instant of chopping
3.13
effective material insulating factor
k
m
coefficient of material, which depends on the electrical insulation material
Note 1 to entry: See IEC 62305-3.
3.14
installation arrangement
installation containing one or more insulating down-conductors and additional installation
means (according to the manufacturer’s instruction) to keep the defined separation distance
and to support the insulating down-conductor mechanically
Note 1 to entry: One example is given in Figure F.1.
4 Insulating stand-off
4.1 Classification
4.1.1 General
Classification of the product depends on the withstand capability of mechanical forces.

– 10 – IEC TS 62561-8:2018 © IEC 2018
4.1.2 According to conductor clamping arrangement
a) Conductor fasteners that are designed to clamp the conductor.
b) Conductor fasteners that are designed to clamp but allow axial movement of the
conductor.
4.1.3 According to mounting
a) Free standing.
b) Rigidly fixed on a structure.
4.2 Requirements
4.2.1 General
An insulating stand-off shall retain, support and insulate the conductor when subjected to the
stress of a lightning discharge under high impulse voltage and shall withstand the mechanical
and environmental influences such as perpendicular and axial compression loads caused by
the weight of the supported conductor along with snow, ice, wind and thermal
expansion/contraction of the conductor.
An insulating stand-off shall be compatible with the conductor it is supporting and the surface
to which it is fixed.
4.2.2 Construction
4.2.2.1 General
An insulating stand-off shall be so designed and constructed that:
– the surface is free from burrs, flash moulding, deformation and similar inconsistencies
which are likely to inflict injury to the installer or user.
Compliance is checked by visual inspection.
– it carries the perpendicular and axial compression loads caused by the weight of the
supported conductor along with snow, ice, wind and thermal expansion/contraction of the
conductor.
Compliance is checked in accordance with 4.3.6.2 and 4.3.6.4.
4.2.2.2 Corrosion resistance
An insulating stand-off shall withstand the effects of corrosion typical of the environment to
which it is exposed.
Compliance is checked by testing in accordance with 4.3.5.1.
4.2.2.3 UV light resistance
An insulating stand-off shall withstand the effects of UV exposure typical of the environment
to which it is exposed.
Compliance is checked by testing in accordance with 4.3.5.2.
4.2.3 Mechanical requirements
4.2.3.1 General
An insulating stand-off may consist of a mounting assembly, an insulator and a conductor
fastener as shown in Figure 1 and/or Figure 2. The manufacturer of the insulating stand-off
shall guarantee with appropriate mechanical tests or calculations that the stand-off fulfils the
requirements stated in his documentation.

Compliance is checked by testing in accordance with 4.3.
3 4
IEC
Key
1 mounting assembly
2 insulator
3 metallic conductor fastener
4 conductor
l insulating length
st
Figure 1 – Typical insulating stand-off with a metallic fastener
l
st
– 12 – IEC TS 62561-8:2018 © IEC 2018
IEC
Key
1 mounting assembly
2 insulator
3 non-metallic conductor fastener
4 conductor
l insulating length
st
Figure 2 – Typical insulating stand-off with a non-metallic fastener
4.2.3.2 Mounting assembly
The mounting assembly which holds the insulator in position on the structure shall withstand
mechanical stress.
Compliance is checked by testing in accordance with 4.3.6.
4.2.3.3 Insulator
The insulator shall withstand mechanical stress, e.g. pull out force, impact strength, bending
load.
Compliance is checked by testing in accordance with 4.3.6.
4.2.3.4 Conductor fastener
The conductor fastener which is part of the insulating stand-off shall comply with the
requirements and tests of IEC 62561-4.
4.2.4 Electrical requirements
An insulating stand-off shall be able to withstand the very high impulse voltages generated by
a lightning strike.
l
st
An insulating stand-off has an insulating length l which is different from its effective length
st
l . The isolating capability of an insulating stand-off may be provided by either
eff
a) its effective length l , or
eff
b) its effective length correction factor k .
x
The effective length correction factor k is determined from the effective length l and the
x eff
insulating length l as follows:
st
l
eff
k =
x
l
st
The effective length l is the value which shall be compared to the required separation
eff
distance s according to IEC 62305-3. This effective length of the insulating stand-off shall be
equal to or greater than the required separation distance s.
Compliance is checked by testing in accordance with 4.3.1, 4.3.2 and 4.3.7.
For the purpose of calculating the separation distance as used in IEC 62305-3, the value k
m
can be set equal to the value k .
x
NOTE Based on experience, a value of k = 0,7 for GFRP, PE and PVC insulating stand-offs under normal
x
operating conditions has been found to be typical.
4.2.5 Documentation
The manufacturer or supplier of the insulating stand-off shall provide adequate information in
the installation instructions to ensure that the installer can select and install the component in
a suitable and safe manner in accordance with the requirements of IEC 62305-3.
Compliance is checked by inspection in accordance with 4.3.3.
4.2.6 Marking
An insulating stand-off shall be marked with:
a) the manufacturer’s or responsible vendor’s name, logo or trademark;
b) product identification or type.
Where it is not possible to make these marks directly onto the product, they shall be provided
on the smallest supplied packaging.
NOTE Marking can be applied, for example, by moulding, pressing, engraving, printing, adhesive labels or water
slide transfers.
Compliance is checked by testing in accordance with 4.3.4.
4.3 Tests
4.3.1 General test conditions
Tests according to this document are type tests. These tests are of such a nature that, after
they have been performed, they need not be repeated unless changes are made to the
materials, design or type of manufacturing process, which might change the performance
characteristics of the insulating stand-off.
Unless otherwise specified, all tests are carried out with the specimens assembled and
installed as in normal use according to the manufacturer's or supplier's instructions, using the
recommended conductor materials, sizes and tightening torques.

– 14 – IEC TS 62561-8:2018 © IEC 2018
The insulating length l of all specimens shall be (500 ± 5) mm unless otherwise specified in
st
the relevant test procedure. The manufacturer shall prepare the test specimens according to
Figure 3 and/or Figure 4.
Dimension in millimetres
IEC
Key
1 mounting assembly
2 insulator
3 metallic conductor fastener
4 conductor
Figure 3 – Typical insulating stand-off with a metallic fastener
prepared for testing
500 ±5
Dimension in millimetres
IEC
Key
1 mounting assembly
2 insulator
3 non-metallic conductor fastener
4 conductor
l insulating length
st
Figure 4 – Typical insulating stand-off with a non-metallic fastener
prepared for testing
This document cannot cover all possible types of insulating stand-offs and the way of fixing
them on various surfaces of different materials. When required for these applications,
agreement should be obtained between the test engineer and manufacturer on the specific
testing regime.
An insulating stand-off classified by the manufacturer in more than one of the classifications
in 4.1 shall be tested for each applicable category.
Type tests are carried out on three specimens according to the test sequence indicated in
Table 1. Within any test sequence, the tests shall be carried out in the order given in
Annex C.
A specimen has passed a test sequence of Table 1 if all the requirements of the relevant test
clauses and the relevant pass criteria have been fulfilled.
If the required number of specimens pass a test sequence, the design of the insulating
stand-off is acceptable for that test sequence. If two or more test specimens fail a test
sequence, the insulating stand-off does not comply with this document.
In the event that a single specimen does not pass a test, this test, and those preceding in the
same test sequence that may have influenced the result of this test, shall be repeated with
l = 500 ±5
st
– 16 – IEC TS 62561-8:2018 © IEC 2018
three new specimens. No failure of any specimen is allowed in the second sequence of tests.
One set of three specimens may be used for more than one test sequence if agreed by the
manufacturer.
The applicants, when submitting the first set of specimens may also submit an additional set
of specimens that may be necessary should one specimen fail. The test house shall then,
without further request, test the additional set of specimens and shall only reject if a further
failure occurs. If the additional set of specimens is not submitted at the same time, a failure of
one specimen shall entail rejection.
Tests shall not commence earlier than 168 h from the time of manufacture.
When not otherwise specified, the test shall be performed in free air, with an ambient
temperature between +15 °C and +40 °C and relative humidity between 25 % and 75 %.
A torque meter having a resolution of at least 0,5 Nm and an accuracy of at least 4 % shall be
used for all tightening operations.
NOTE Upon the instructions of the manufacturer, a set of specimens previously tested may also be suitable for
use in other tests of this document as well.
Table 1 – Type test requirements for an insulating stand-off
Identification of
Test sets (one set
Test description Subclause Number of specimens
sequence consists of three
specimens)
1 Documentation 4.3.3 A 1
Marking test 4.3.4 A 3
Construction 4.3.6.1 A 3
9 or more due to surface
UV light test 4.3.5.2 B,C,D deterioration during high voltage
test.
Corrosion test 4.3.5.1 A 3
Pull out test 4.3.6.4 A 3
Bending test 4.3.6.2 B 3
Impact test of the insulator 4.3.6.3 C 3
3 or more due to surface
Electrical test 4.3.7 D deterioration during high voltage
test.
4.3.2 General test setup
Unless otherwise specified by the manufacturer, the conductors and specimens shall be
cleaned by using a suitable degreasing agent followed by cleaning in demineralized water and
drying. They shall then be assembled according to the manufacturer’s installation instructions,
e.g. with the recommended conductors and tightening torques.
The tightening torque should be applied in a steady and uniform manner.
Any insulating stand-off accommodating a range of conductor diameters shall be tested on the
minimum conductor size recommended.

4.3.3 Documentation
The manufacturer or responsible vendor shall provide the following in his literature:
a) the classifications according to 4.1;
b) the maximum and minimum conductor dimensions;
c) the conductor materials to be used;
d) the type of mounting surface to be fixed;
e) the recommended method of assembly, installation and fixing to the mounting surface;
f) the pull out force;
g) the bending force;
h) the mechanical strength (e.g. load torque, support load);
coefficient.
i) the k
x
Compliance is checked by inspection.
4.3.4 Marking test
Marking on the product shall be durable and easily legible.
The durability of marking shall be tested by easy rubbing for ten times with a piece of cloth
soaked with water.
Markings made by moulding, pressing or engraving are not subjected to this test.
Pass criteria:
The specimen is deemed to have passed the test if the marking remains legible.
Marking may be applied, for example, by moulding, pressing, engraving, printing, adhesive
labels, etc.
4.3.5 Environmental influence tests
4.3.5.1 Corrosion test
An insulating stand-off with metallic components, including its conductor fastener and
mounting assembly shall be subjected to environmental influence tests consisting of a salt
mist test as specified in A.2 followed by a humid sulphurous atmosphere test as specified in
A.3. An additional test by an ammonia atmosphere as specified in A.4 shall be carried out on
an insulating stand-off having parts made of copper alloy with a copper content less than
80 %.
Pass criteria:
The specimens are deemed to have passed the test if no base metals of the metallic
components show any corrosive deterioration visible to normal or corrected vision.
NOTE White rust, patina and surface oxidation are not considered as corrosive deterioration.
4.3.5.2 UV light test
The insulating part (insulator) of the insulating stand-off shall be subjected to an
environmental test consisting of an ultraviolet light test as specified in Annex B.

– 18 – IEC TS 62561-8:2018 © IEC 2018
The length of the test specimen shall be sufficient so that after the UV light test, a complete
insulating stand-off can be assembled for further tests requiring an insulating length l of
st
(500 ± 5) mm.
Pass criteria:
The specimens are deemed to have passed the test, if there are no signs of disintegration
and cracks visible under normal or corrected
...