SIST EN IEC 62561-8:2026
(Main)Lightning protection system components (LPSC) - Part 8: Requirements for components for electrically insulated LPS
- Abstract
IEC 62561-8:2026 specifies the requirements and tests for components used for electrically insulated LPS. These components, which can reduce the separation distance, are as follows:
- insulating stand-offs, used in conjunction with an air-termination system and down-conductors with the aim of maintaining the proper separation distance;
- insulating down‑conductors, including their specific fasteners.
Testing of insulating stand-offs and insulating down-conductor components for an explosive atmosphere is not covered by this document. This first edition cancels and replaces IEC TS 62561-8 published in 2018. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to IEC TC 62561-8:2018:
a) title and scope of the standard has been adjusted;
b) the document has been updated in line with IEC 60068-2-52:2017 on salt mist treatment;
c) the document has been updated in line with ISO 22479:2019 on humid sulphureous atmosphere treatment;
d) two different possible example configurations for pull out tests have been introduced;
e) additional information on pollution has been included;
f) an alternate test arrangement for high voltage impulse test has been included;
g) a new normative Annex H for applicability of previous tests has been introduced;
h) pass criteria for high voltage impulse testing updated;
i) explanation on high voltage impulse testing with negative polarity has been added.
- Status
- Published
- Public Enquiry End Date
- 29-Sep-2025
- Publication Date
- 13-Sep-2026
- Technical Committee
- STZ - Lightning protection
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 04-Sep-2026
- Due Date
- 09-Nov-2026
- Completion Date
- 14-Sep-2026
SIST EN IEC 62561-8:2026 is the Slovenian adoption of EN IEC 62561-8:2026, published by SIST from IEC 62561-8:2026. It specifies requirements and tests for lightning protection system components (LPSC) used in electrically insulated LPS, mainly insulating stand-offs and insulating down-conductors. For manufacturers, test laboratories, installers and specifiers, it shows how these parts are classified, marked, documented and type-tested so they can maintain the required separation distance in a lightning protection system designed according to the IEC 62305 series.
What does SIST EN IEC 62561-8:2026 specify?
SIST EN IEC 62561-8:2026 covers the requirements and tests for components used in electrically insulated LPS. The scope is focused on two product groups that reduce the separation distance: insulating stand-offs and insulating down-conductors, including the specific fasteners for insulating down-conductors.
The document is organized into:
- Clause 1 scope
- Clause 2 normative references
- Clause 3 terms and definitions
- Clause 4 insulating stand-off
- Clause 5 insulating down-conductor
- Annexes A to H, with a mix of normative and informative material
| Annex | What it covers |
|---|---|
| A | Corrosion resistance tests |
| B | Resistance to ultraviolet light |
| C | Flow chart of tests for insulating stand-offs |
| D | Flow chart of tests for insulating down-conductors |
| E | Informative high voltage impulse test to determine the correction factor k for insulating stand-offs |
| F | Informative installation arrangement test for the influence of supporting structures on separation distance |
| G | Alternate test arrangement for the high voltage impulse test |
| H | Applicability of previous tests |
The scope excludes testing of insulating stand-offs and insulating down-conductor components for an explosive atmosphere.
What are the key requirements of SIST EN IEC 62561-8:2026?
SIST EN IEC 62561-8:2026 sets out type-test based requirements for two component families. In practice, the standard asks the manufacturer to define the product class, prove mechanical and electrical performance, provide installation information, and show that the marking remains legible after simple wear tests.
Insulating stand-offs
Clause 4 requires an insulating stand-off to retain, support and insulate the conductor under lightning impulse stress and under mechanical and environmental loads. That matters because these parts carry the air-termination system or down-conductors while keeping safe distance from the structure.
The stand-off is classified by conductor clamping arrangement and by mounting, with classes for free-standing and rigidly fixed products. This helps users match the component to the actual installation method instead of treating all stand-offs as interchangeable.
Clause 4 also requires construction that avoids burrs, flash and similar defects, plus compatibility with the conductor and mounting surface. The stand-off must also withstand corrosion and UV exposure typical of the installation environment.
For electrical performance, the stand-off has an insulating length and an effective length. The effective length, or the effective length correction factor k, is what is compared with the required separation distance s from IEC 62305-3. In practice, this means the component must prove that it can substitute for the separation distance required in the lightning protection design.
Insulating down-conductors
Clause 5 classifies insulating down-conductors by lightning current carrying capability and also classifies their fasteners by material and fixing arrangement. That matters because the conductor, its insulation and its fixings must all work together under lightning stress.
The down-conductor shall be suitable for the required separation distance s and shall use dedicated fasteners so that the conductor and insulation are not damaged during installation. The manufacturer also has to provide documentation that lets the installer select and fit the product correctly.
Clause 5 requires the metallic parts to withstand corrosion and the non-metallic parts to withstand UV exposure. It also requires the down-conductor to meet the mechanical requirements of IEC 62561-2, unless the product proves its electrical performance by the relevant test.
For electrical performance, the standard requires two different checks: lightning current carrying capability and high voltage impulse withstand for the equivalent separation distance. This is what proves that the product can both carry the lightning current and keep the insulation distance needed in service.
Type testing, specimen preparation and pass criteria
For both product families, the document uses type tests on three specimens and specifies the order of tests in Annex C or Annex D. The specimens are assembled as in normal use, with the manufacturer’s recommended conductors, connectors and tightening torques. That means the test result reflects the product as it is actually installed.
The tests cover documentation review, marking, construction, environmental conditioning, mechanical tests and electrical tests. If one specimen fails, the failed sequence is repeated on three new specimens, and no failure is allowed in the repeat sequence.
The high voltage impulse tests use comparison arrangements and negative polarity. For stand-offs, the test verifies the correction factor k; for down-conductors, it verifies the equivalent separation distance s. Annex G allows an alternate rod-plane arrangement, and Annex F gives a test for installation arrangements where supporting structures can influence the dielectric performance.
Reporting and EMC
Clauses 4.5 and 5.7 define the content of the test report. The report has to identify the specimen, the test methods, the equipment, the measuring instruments, the results and the pass or fail statement. The standard also treats the products as passive with respect to electromagnetic influences.
What terms does SIST EN IEC 62561-8:2026 define?
SIST EN IEC 62561-8:2026 defines the terms that make the electrical and mechanical checks unambiguous.
- Insulating stand-off - A non-metallic or composite component that supports and insulates the air-termination system or down-conductors at the required separation distance.
- Insulating down-conductor - A conductor with an electrical insulation layer used to reduce the separation distance.
- Equivalent separation distance s - The corrected distance value used instead of the stand-off insulating length when checking the required separation distance.
- Effective length correction factor k - The factor used to relate the insulating stand-off geometry to its electrical withstand behavior.
- Effective length - The air-gap length that has breakdown behavior equivalent to the insulating stand-off.
- Installation arrangement - The complete installation with one or more insulating down-conductors and supporting means used to hold the distance and support the conductor mechanically.
- Steepness correction factor - A factor used in the impulse tests to account for the effect of steep-front voltages and subsequent negative short strokes.
Who uses SIST EN IEC 62561-8:2026?
SIST EN IEC 62561-8:2026 is used by manufacturers of lightning protection components, especially producers of insulating stand-offs, insulating down-conductors and their fasteners. They use it to design products, prepare type tests, write installation instructions and decide what to mark on the product or packaging.
Testing and certification laboratories use it to set up the environmental, mechanical and high voltage impulse tests and to prepare the test report. Installers and lightning protection designers use it when choosing components for an LPS based on the IEC 62305 series. Quality managers and buyers use it to check whether a product’s declared class, separation distance, marking and documentation fit the intended application.
What changed in SIST EN IEC 62561-8:2026 from the previous edition?
SIST EN IEC 62561-8:2026 is the first edition and it cancels and replaces IEC TS 62561-8:2018. The document states these technical changes relative to the 2018 technical specification:
- title and scope adjusted
- updated to IEC 60068-2-52:2017 for salt mist treatment
- updated to ISO 22479:2019 for humid sulphureous atmosphere treatment
- two example pull-out test configurations added
- additional information on pollution added
- alternate high voltage impulse test arrangement added
- new normative Annex H on applicability of previous tests added
- pass criteria for high voltage impulse testing updated
- explanation added for high voltage impulse testing with negative polarity
Which standards are used with SIST EN IEC 62561-8:2026?
SIST EN IEC 62561-8:2026 relies on a set of normative references for test equipment, environmental conditioning and related lightning protection parts.
- IEC 60060-2:2025 - measuring systems for high-voltage tests
- IEC 60068-2-52:2017 - salt mist environmental testing
- IEC 60068-2-75:2014 - hammer impact testing
- IEC 61083-1 and IEC 61083-2 - instruments and software for impulse measurements
- IEC 62305-3 - the lightning protection design basis for separation distance
- IEC 62561-1:2023 - connection components and lightning impulse current test methods
- IEC 62561-2:2025 - conductors and earth electrodes
- IEC 62561-4 - conductor fasteners
- ISO 4892-2, ISO 4892-3:2024 and ISO 4892-4 - UV exposure methods for plastics
- ISO 6957:1988 - ammonia atmosphere stress-corrosion test for copper alloys
- ISO 22479:2019 - humid sulphurous atmosphere corrosion test
The introduction also places the document within the IEC 62305 series for lightning protection of structures, and the bibliography lists IEC 62305-1:2024, IEC 62305-2:2024 and IEC 62305-4:2024 as related parts.
What does the SIST EN IEC 62561-8:2026 document contain?
SIST EN IEC 62561-8:2026 contains classification tables, type-test sequences, specimen preparation rules, environmental test methods, mechanical test methods, electrical test arrangements and report requirements. It includes formulas and comparison arrangements for the high voltage impulse tests, plus figures showing typical stand-off and down-conductor setups and alternate arrangements.
The annexes add the practical laboratory content: salt mist and corrosion procedures in Annex A, UV conditioning options in Annex B, flow charts in Annex C and D, informative methods for determining k in Annex E, an installation arrangement test in Annex F, an alternate high voltage setup in Annex G, and a legacy-use provision in Annex H. In practice, this means the document is mainly a laboratory and product-verification standard for proving that electrically insulated LPS components perform as declared.
Relations
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 14-Jul-2026
- Effective Date
- 18-Aug-2026
- Effective Date
- 18-Aug-2026
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Frequently Asked Questions
SIST EN IEC 62561-8:2026 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Lightning protection system components (LPSC) - Part 8: Requirements for components for electrically insulated LPS". This standard covers: IEC 62561-8:2026 specifies the requirements and tests for components used for electrically insulated LPS. These components, which can reduce the separation distance, are as follows: - insulating stand-offs, used in conjunction with an air-termination system and down-conductors with the aim of maintaining the proper separation distance; - insulating down‑conductors, including their specific fasteners. Testing of insulating stand-offs and insulating down-conductor components for an explosive atmosphere is not covered by this document. This first edition cancels and replaces IEC TS 62561-8 published in 2018. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC TC 62561-8:2018: a) title and scope of the standard has been adjusted; b) the document has been updated in line with IEC 60068-2-52:2017 on salt mist treatment; c) the document has been updated in line with ISO 22479:2019 on humid sulphureous atmosphere treatment; d) two different possible example configurations for pull out tests have been introduced; e) additional information on pollution has been included; f) an alternate test arrangement for high voltage impulse test has been included; g) a new normative Annex H for applicability of previous tests has been introduced; h) pass criteria for high voltage impulse testing updated; i) explanation on high voltage impulse testing with negative polarity has been added.
IEC 62561-8:2026 specifies the requirements and tests for components used for electrically insulated LPS. These components, which can reduce the separation distance, are as follows: - insulating stand-offs, used in conjunction with an air-termination system and down-conductors with the aim of maintaining the proper separation distance; - insulating down‑conductors, including their specific fasteners. Testing of insulating stand-offs and insulating down-conductor components for an explosive atmosphere is not covered by this document. This first edition cancels and replaces IEC TS 62561-8 published in 2018. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to IEC TC 62561-8:2018: a) title and scope of the standard has been adjusted; b) the document has been updated in line with IEC 60068-2-52:2017 on salt mist treatment; c) the document has been updated in line with ISO 22479:2019 on humid sulphureous atmosphere treatment; d) two different possible example configurations for pull out tests have been introduced; e) additional information on pollution has been included; f) an alternate test arrangement for high voltage impulse test has been included; g) a new normative Annex H for applicability of previous tests has been introduced; h) pass criteria for high voltage impulse testing updated; i) explanation on high voltage impulse testing with negative polarity has been added.
SIST EN IEC 62561-8:2026 is classified under the following ICS (International Classification for Standards) categories: 29.020 - Electrical engineering in general; 91.120.40 - Lightning protection. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN IEC 62561-8:2026 has the following relationships with other standards: It is inter standard links to SIST EN IEC 62561-2:2026, SIST EN ISO 4892-3:2024, SIST EN IEC 60060-2:2025, SIST EN IEC 62561-1:2023, SIST EN IEC 62305-3:2024, SIST EN IEC 60068-2-52:2018, SIST EN IEC 62561-4:2024, SIST EN 60068-2-75:2014, SIST EN ISO 22479:2022, SIST EN 61083-2:2013, SIST EN ISO 4892-2:2013, SIST EN IEC 62305-4:2024, SIST EN 16282-3:2017. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN IEC 62561-8:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2026
Elementi za zaščito pred strelo (LPSC) - 8. del: Zahteve za elemente električno
izoliranega sistema LPS (IEC 62561-8:2026)
Lightning protection system components (LPSC) - Part 8: Requirements for components
for electrically insulated LPS
Blitzschutzsystembauteile (LPSC) - Teil 8: Anforderungen an Bauteile für ein elektrisch
isoliertes Blitzschutzsystem (LPS) (IEC 62561-8:2026)
Composants de système de protection contre la foudre (CSPF) - Partie 8: Exigences
pour les composants de système isolé de protection contre la foudre (IEC 62561-8:2026)
Ta slovenski standard je istoveten z: EN IEC 62561-8:2026
ICS:
91.120.40 Zaščita pred strelo Lightning protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 62561-8
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2026
ICS 29.020; 91.120.40
English Version
Lightning protection system components (LPSC) - Part 8:
Requirements for components for electrically insulated LPS
(IEC 62561-8:2026)
Composants des systèmes de protection contre la foudre Blitzschutzsystembauteile (LPSC) - Teil 8: Anforderungen
(CSPF) - Partie 8: Exigences pour les composants de an Bauteile für ein elektrisch isoliertes Blitzschutzsystem
système électriquement isolé de protection contre la foudre (LPS)
(IEC 62561-8:2026) (IEC 62561-8:2026)
This European Standard was approved by CENELEC on 2026-07-20. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62561-8:2026 E
European foreword
The text of document 81/806/FDIS, future edition 1 of IEC 62561-8, prepared by TC 81 "Lightning
protection" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-08-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-08-31
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62561-8:2026 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 62305 (series) NOTE Approved as EN IEC 62305 (series)
IEC 62305-1:2024 NOTE Approved as EN IEC 62305-1:2024 (not modified)
IEC 62305-2:2024 NOTE Approved as EN IEC 62305-2:2024 (not modified)
IEC 62305-4:2024 NOTE Approved as EN IEC 62305-4:2024 (not modified)
IEC 61034 (series) NOTE Approved as EN 61034 (series)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60060-2 2025 High-voltage test techniques - Part 2: EN IEC 60060-2 2025
Measuring systems
IEC 60068-2-52 2017 Environmental testing - Part 2-52: Tests - EN IEC 60068-2-52 2018
Test Kb: Salt mist, cyclic (sodium chloride
solution)
IEC 60068-2-75 2014 Environmental testing - Part 2-75: Tests - EN 60068-2-75 2014
Test Eh: Hammer tests
IEC 61083-1 - Instruments and software used for EN 61083-1 -
measurements in high-voltage and high-
current tests - Part 1: Requirements for
instruments for impulse tests
IEC 61083-2 - Instruments and software used for EN 61083-2 -
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 EN IEC 62305-3 -
damage to structures and life hazard
IEC 62561-1 2023 Lightning protection system components EN IEC 62561-1 2023
(LPSC) - Part 1: Requirements for
connection components
IEC 62561-2 2025 Lightning protection system components EN IEC 62561-2 2025
(LPSC) - Part 2: Requirements for
conductors and earth electrodes
IEC 62561-4 - Lightning protection system components EN IEC 62561-4 -
(LPSC) - Part 4: Requirements for conductor
fasteners
ISO 4892-2 - Plastics - Methods of exposure to laboratory EN ISO 4892-2 -
light sources - Part 2: Xenon-arc lamps
ISO 4892-3 2024 Plastics - Methods of exposure to laboratory EN ISO 4892-3 2024
light sources - Part 3: Fluorescent UV lamps
Publication Year Title EN/HD Year
ISO 4892-4 - Plastics - Methods of exposure to laboratory - -
light sources - Part 4: Open-flame carbon-
arc lamps
ISO 6957 1988 Copper alloys; ammonia test for stress - -
corrosion resistance
ISO 22479 2019 Corrosion of metals and alloys - Sulfur EN ISO 22479 2022
dioxide test in a humid atmosphere (fixed
gas method)
IEC 62561-8 ®
Edition 1.0 2026-06
INTERNATIONAL
STANDARD
Lightning protection system components (LPSC) -
Part 8: Requirements for components for electrically insulated LPS
ICS 29.020; 91.120.40 ISBN 978-2-8327-1299-3
IEC 62561-8:2026-06(en)
IEC 62561-8:2026 © IEC 2026
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Insulating stand-off . 10
4.1 Classification . 10
4.1.1 General . 10
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 . 11
4.2.4 Electrical requirements . 12
4.2.5 Documentation and installation instructions . 13
4.2.6 Marking . 13
4.3 Tests . 14
4.3.1 General test conditions . 14
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 . 22
4.4 Electromagnetic compatibility (EMC) . 24
4.5 Structure and content of the test report . 25
4.5.1 General . 25
4.5.2 Report identification . 25
4.5.3 Specimen description . 25
4.5.4 Characterization and condition of the test specimen or test assembly . 26
5 Insulating down-conductor . 27
5.1 Classification . 27
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 . 28
5.4.3 Mechanical requirements . 28
5.4.4 Electrical requirements . 28
5.4.5 Documentation . 29
5.4.6 Marking . 29
5.5 Tests . 30
5.5.1 General test conditions . 30
5.5.2 General test setup . 31
5.5.3 Documentation . 31
IEC 62561-8:2026 © IEC 2026
5.5.4 Marking test . 31
5.5.5 Environmental influence tests . 32
5.5.6 Mechanical tests . 33
5.5.7 Electrical tests . 33
5.6 Electromagnetic compatibility (EMC) . 38
5.7 Structure and content of the test report . 38
5.7.1 General . 38
5.7.2 Report identification . 39
5.7.3 Specimen description . 39
5.7.4 Characterization and condition of the test specimen or test assembly . 39
5.7.5 Insulating down-conductor . 39
5.7.6 Standards and references . 39
5.7.7 Test procedure . 40
5.7.8 Testing equipment description . 40
5.7.9 Measuring instruments description . 40
5.7.10 Results and parameters recorded . 40
Annex A (normative) Environmental test – Corrosion resistance . 41
A.1 General . 41
A.2 Salt mist test . 41
A.3 Humid sulphurous atmosphere test . 41
A.4 Ammonia atmosphere test. 41
Annex B (normative) Environmental test – Resistance to ultraviolet light . 42
B.1 General . 42
B.2 Test . 42
B.3 First alternative test to Clause B.2 . 42
B.4 Second alternative test to Clause B.2 . 42
Annex C (normative) Flow chart of tests for insulating stand-offs . 43
Annex D (normative) Flow chart of tests for insulating down-conductors . 44
Annex E (informative) High voltage impulse test to determine the actual correction
factor k for insulating stand-offs . 45
x
E.1 Specimen preparation . 45
E.2 Test setup . 45
E.3 Test procedure. 45
Annex F (informative) Installation arrangement test to determine the influence of
supporting structures on the separation distance . 47
F.1 General . 47
F.2 Specimen preparation for the high voltage installation arrangement test . 47
F.3 Test procedure. 48
Annex G (normative) Alternate test arrangement for high voltage impulse test . 49
Annex H (normative) Applicability of previous tests . 52
Bibliography . 53
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 . 18
IEC 62561-8:2026 © IEC 2026
Figure 6 – Pendulum hammer test apparatus . 19
Figure 7 – Two alternative basic arrangements for pull out test on rigidly fixed
insulating stand-off . 21
Figure 8 – Two alternative basic arrangements for pull out test on free standing
insulating stand-off . 22
Figure 9 – Typical test arrangement for the high voltage impulse test of an insulating
stand-off . 23
Figure 10 – Specimen preparation for UV light test . 32
Figure 11 – Basic arrangement for the lightning current carrying capability test . 34
Figure 12 – Test arrangements for the high voltage impulse test of the insulating down-
conductor . 36
Figure 13 – Test arrangements for insulting down conductors . 37
Figure C.1 – Tests for insulating stand-offs . 43
Figure D.1 – Tests for insulating down-conductors . 44
Figure F.1 – Example for installation arrangement test – Specimen under test . 47
Figure F.2 – Alternate example for installation arrangement test – Specimen under test . 48
Figure G.1 – Typical test arrangement for the high voltage impulse test of an insulating
stand-off – Alternate test arrangement to Figure 9 . 49
Figure G.2 – General description of the test setup for the high voltage impulse test of
the insulating down-conductor – Alternate test set-up to Figure 12 a) . 50
Figure G.3 – Alternate test arrangement for the high voltage impulse test of the
insulating down conductor – alternate test set-up to Figure 12 b) . 50
Figure G.4 – General description rod tip and rod – Plane arrangement geometry . 51
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 . 31
Table H.1 – Differences in the requirements for electrically insulated LPS complying
with IEC TS 62561-8:2018 . 52
IEC 62561-8:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Lightning protection system components (LPSC) -
Part 8: Requirements for components for electrically insulated 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 international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
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the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 62561-8 has been prepared by IEC technical committee 81: Lightning protection. It is an
International Standard.
This first edition cancels and replaces IEC TS 62561-8 published in 2018. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to IEC TC
62561-8:2018:
a) title and scope of the standard has been adjusted;
b) the document has been updated in line with IEC 60068-2-52:2017 on salt mist treatment;
c) the document has been updated in line with ISO 22479:2019 on humid sulphureous
atmosphere treatment;
d) two different possible example configurations for pull out tests have been introduced;
e) additional information on pollution has been included;
IEC 62561-8:2026 © IEC 2026
f) an alternate test arrangement for high voltage impulse test has been included;
g) a new normative Annex H for applicability of previous tests has been introduced;
h) pass criteria for high voltage impulse testing updated;
i) explanation on high voltage impulse testing with negative polarity has been added.
The text of this International Standard is based on the following documents:
Draft Report on voting
81/806/FDIS 81/808/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 62561 series, published under the general title Lightning protection
system components (LPSC), 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, or
– revised.
IEC 62561-8:2026 © IEC 2026
INTRODUCTION
This part of IEC 62561 deals with the requirements and tests for lightning protection system
components (LPSC), specifically components for electrically insulated LPS, used for the
installation of a lightning protection system (LPS) designed and implemented according to the
IEC 62305 series [1] .
___________
Numbers in square brackets refer to the Bibliography.
IEC 62561-8:2026 © IEC 2026
1 Scope
This document specifies the requirements and tests for components used for electrically
insulated LPS. These components, which can reduce the separation distance, are as follows:
– insulating stand-offs, used in conjunction with an air-termination system and down-
conductors with the aim of maintaining the proper separation distance;
– insulating down-conductors, including their specific fasteners.
Testing of insulating stand-offs and insulating down-conductor components for an explosive
atmosphere is not covered by this document.
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 60060-2:2025, High-voltage test techniques - Part 2: Measuring systems
IEC 60068-2-52:2017, Environmental testing - Part 2-52: Tests - Test Kb: Salt mist, cyclic
(sodium chloride solution)
IEC 60068-2-75:2014, Environmental testing - Part 2-75: Tests - Test Eh: Hammer tests
IEC 61083-1, Instruments and software used for measurements in high-voltage and
high-current tests - Part 1: Requirements for instruments for impulse tests
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 62561-1:2023, Lightning protection system components (LPSC) - Part 1: Requirements for
connection components
IEC 62561-2:2025, 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
ISO 4892-3:2024, 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 6957:1988, Copper alloys - Ammonia test for stress corrosion resistance
IEC 62561-8:2026 © IEC 2026
ISO 22479:2019, Corrosion of metals and alloys - Sulfur dioxide test in a humid atmosphere
(fixed gas 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
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 or down-conductors at a required
separation distance
3.2
effective length correction factor
k
x
factor evaluating the different withstand voltages of air gaps and insulators under test voltages
3.3
steepness correction factor
c
is_st
factor considering the effect of higher steepness and the probability of
occurrence of subsequent negative short strokes on the disruptive voltage of an insulating
stand-off
Note 1 to entry: The value is defined in the test procedure.
3.4
effective length
l
eff
length (distance) of an air gap with equivalent breakdown behaviour to
an insulating stand-off
3.5
insulating length
l
st
shortest measured clearance distance between two conductive elements
of different electrical potential, for example 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
IEC 62561-8:2026 © IEC 2026
3.7
down-conductor
part of the down-conductor system intended to conduct lightning current from the air-termination
system to the earth-termination system of the LPS
[SOURCE: IEC 62561-2:2025, 3.7]
3.8
insulating down-conductor
conductor provided with a layer of electric insulation with the purpose to reduce the separation
distance
3.9
steepness correction factor
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
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
3.11
time to chopping
T
c
virtual parameter defined as the interval between the virtual origin and the instant of chopping
3.12
effective material insulating factor
k
m
coefficient of material which depends on the electrical insulation material
Note 1 to entry: See IEC 62305-3.
3.13
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.
3.14
fasteners for insulating down-conductors
metallic, non-metallic or composite components designed to retain and support down-conductor
installed at intervals along the length of the conductors
IEC 62561-8:2026 © IEC 2026
4 Insulating stand-off
4.1 Classification
4.1.1 General
Classification of the product depends on the withstand capability of mechanical forces.
4.1.2 According to conductor clamping arrangement
There are two classes of insulating stand-off according to the conducting 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
Regarding the mounting, there are two classes of insulating stand-off:
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 or
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
a) the surface is free from burrs, flash moulding, deformation and similar inconsistencies which
are likely to inflict injury to the installer or user, and
b) 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 to a) is checked by visual inspection and compliance to b) 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.
IEC 62561-8:2026 © IEC 2026
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 can consist of a mounting assembly, an insulator and a conductor
fastener as shown in Figure 1 and Figure 2. The manufacturer of the insulating stand-off shall
guarantee with appropriate mechanical tests or calculations that the stand-off fulfills the
requirements stated in their documentation.
Compliance is checked by testing in accordance with 4.3.
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
IEC 62561-8:2026 © IEC 2026
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, for example pull out force, impact strength and
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 capable of withstanding the very high impulse voltages
generated by a lightning strike.
IEC 62561-8:2026 © IEC 2026
An insulating stand-off has an insulating length l , as shown in Figure 1 and Figure 2. This is
st
different from its effective length l , which is the value to be compared to the required
eff
separation 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.
The isolating capability of an insulating stand-off can be provided by either
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 showed in Formula (1):
st
I
eff
k =
(1)
x
I
st
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 of the
effective material insulating factor k can be set equal to the value k .
m x
NOTE A value of k = 0,7 for GFRP, PE and PVC insulating stand-offs under normal operating conditions can be
x
used, based on laboratory test results [2].
4.2.5 Documentation and installation instructions
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
4.2.6.1 Content of marking
An insulating stand-off shall be marked with
a) the manufacturer's or responsible vendor's name, logo or trademark, and
b) the 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.
Compliance is checked by visual inspection.
4.2.6.2 Durability and legibility
Marking on the product shall be durable and easily legible.
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.
IEC 62561-8:2026 © IEC 2026
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 are not required to be repeated unless changes are made to
the materials, design or type of manufacturing process, which can change the performance
characteristics of the insulating stand-off.
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.
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 for a metallic fastener or Figure 4 for a non-metallic fastener.
Dimensions in millimetres
Key
1 mounting assembly
2 insulator
3 metallic conductor fastener
4 conductor
l insulating length
st
Figure 3 – Typical insulating stand-off with a metallic fastener prepared for testing
IEC 62561-8:2026 © IEC 2026
Dimensions in millimetres
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 passes 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 could have influenced the result of this test, shall be repeated with
three new specimens. No failure of any specimen is allowed in the second sequence of tests.
One set of three specimens can be used for more than one test sequence if agreed by the
manufacturer.
IEC 62561-8:2026 © IEC 2026
The applicants, when submitting the first set of specimens, can also submit an additional set of
specimens that can 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 on non-metallic specimens shall not commence earlier than 168 h from the
...