IEC 61854:2020
(Main)Overhead lines - Requirements and tests for spacers
Overhead lines - Requirements and tests for spacers
IEC 61854:2020 applies to spacers for conductor bundles of overhead lines. It covers rigid spacers, flexible spacers and spacer dampers.
It does not apply to interphase spacers, hoop spacers and bonding spacers.
This document is written to cover the line design practices and spacers most commonly used at the time of writing. There may be other spacers available for which the specific tests reported in this document may not be applicable.
In some cases, test procedures and test values are left to agreement between purchaser and supplier and are stated in the procurement contract. The purchaser is best able to evaluate the intended service conditions, which should be the basis for establishing the test severity.
In Annex A, the minimum technical details to be agreed between purchaser and supplier are listed.
This second edition cancels and replaces the first edition published in 1998. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Consider the application of spacers on high temperature conductors specifying additional high temperature tests in clamp slip tests and for the characterization of elastic and damping properties;
b) Specify as far as possible test parameters and acceptance values;
c) Avoid as far as possible the alternative procedures for the same test;
d) Introduce a simpler test device for the simulated short circuit current test;
e) Introduce test at low temperature on fastener components such as break away bolts and conical spring washers;
f) Prescribe a different procedure for subspan oscillation tests on spacers equipped with clamps having rod attachments;
g) Modify the test procedure for the aeolian vibration tests;
h) Prescribe a different procedure for aeolian vibration tests on spacers equipped with clamps having rod attachments;
i) Re-edit all the figures in order to make them more clear and homogeneous;
j) Introduce an additional test device for the simulated short circuit current test.
Key words: Overhead Lines, Spacers
Lignes aériennes - Exigences et essais applicables aux entretoises
IEC 61854:2020 s'applique aux entretoises destinées aux faisceaux de conducteurs de lignes aériennes. Il couvre les entretoises rigides, les entretoises souples et les entretoises amortisseuses. Il ne s'applique pas aux espaceurs, aux écarteurs à anneaux et aux entretoises de mise à la terre.
Le présent document a été élaboré pour couvrir les pratiques de conception de lignes, ainsi que les entretoises les plus couramment utilisées au moment de sa rédaction. Il peut exister d'autres entretoises pour lesquelles les essais spécifiques décrits dans le présent document peuvent ne pas s'appliquer.
Dans certains cas, les procédures d'essai et les valeurs d'essai sont convenues entre l'acheteur et le fournisseur et sont indiquées dans le contrat d'approvisionnement. L'acheteur est le mieux à même d'évaluer les conditions de service prévues, qu'il convient d'utiliser comme base pour la définition de la sévérité des essais.
L'Annexe A répertorie les informations techniques minimales à convenir entre l'acheteur et le fournisseur.
Cette deuxième édition annule et remplace la première édition parue en 1998. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) prise en compte de l'application des entretoises sur des conducteurs haute température, avec la spécification d'essais à haute température supplémentaires dans le cadre des essais de glissement des pinces et la caractérisation des propriétés élastiques et d'amortissement;
b) spécification la plus large possible des paramètres d'essai et des valeurs de réception associées;
c) affranchissement, dans la mesure du possible, par rapport aux procédures alternatives pour le même essai;
d) introduction d'un dispositif d'essai plus simple pour l'essai de courant de court-circuit simulé;
e) introduction d'un essai à basse température sur les composants de fixation tels que les boulons fusibles et les rondelles élastiques coniques;
f) prescription d'une procédure différente pour les essais d'oscillation de sous-portée sur les entretoises équipées de pinces avec garnitures;
g) modification de la procédure d'essai pour les essais de vibrations éoliennes;
h) prescription d'une procédure différente pour les essais de vibrations éoliennes sur les entretoises équipées de pinces avec garnitures;
i) reprise de l'ensemble des figures afin de les rendre plus claires et homogènes;
j) introduction d'un dispositif d'essai supplémentaire pour l'essai de courant de court-circuit simulé.
Mots-clés: lignes aériennes, entretoises
General Information
Relations
Standards Content (Sample)
IEC 61854 ®
Edition 2.0 2020-02
REDLINE VERSION
INTERNATIONAL
STANDARD
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Overhead lines – Requirements and tests for spacers
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IEC 61854 ®
Edition 2.0 2020-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Overhead lines – Requirements and tests for spacers
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.20 ISBN 978-2-8322-7900-7
– 2 – IEC 61854:2020 RLV © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 8
4 General requirements . 8
4.1 Design . 8
4.2 Materials . 9
4.2.1 General . 9
4.2.2 Non-metallic materials . 9
4.3 Mass, dimensions and tolerances . 9
4.4 Protection against corrosion . 9
4.5 Manufacturing appearance and finish . 9
4.6 Marking . 10
4.7 Installation instructions . 10
4.8 Specimen . 10
5 Quality assurance . 10
6 Classification of tests. 10
6.1 Type tests . 10
6.1.1 General . 10
6.1.2 Application . 10
6.2 Sample tests . 11
6.2.1 General . 11
6.2.2 Application . 11
6.2.3 Sampling and acceptance criteria . 11
6.3 Routine tests. 11
6.3.1 General . 11
6.3.2 Application and acceptance criteria . 11
6.4 Table of tests to be applied . 11
7 Test methods . 14
7.1 Visual examination . 14
7.2 Verification of dimensions, materials and mass . 14
7.3 Corrosion protection test . 14
7.3.1 Hot dip galvanized components (other than stranded galvanized steel
wires) . 14
7.3.2 Ferrous components protected from corrosion by methods other than
hot dip galvanizing . 15
7.3.3 Stranded galvanized steel wires . 15
7.3.4 Corrosion caused by non-metallic components . 15
7.4 Non-destructive tests . 15
7.5 Mechanical tests . 15
7.5.1 Clamp slip tests . 15
7.5.2 Tests on bolt sets . 23
7.5.3 Simulated short-circuit current test and compression and tension tests . 26
7.5.4 Characterisation of the elastic and damping properties . 33
7.5.5 Flexibility tests . 37
7.5.6 Fatigue tests . 40
7.6 Tests to characterise elastomers . 45
7.6.1 General . 45
7.6.2 Tests . 45
7.6.3 Ozone resistance test . 45
7.7 Electrical tests . 47
7.7.1 Corona and radio interference voltage (RIV) tests. 47
7.7.2 Electrical resistance test . 48
7.8 Verification of vibration behaviour of the bundle/spacer system . 49
Annex A (normative) Minimum technical details to be agreed between purchaser and
supplier . 50
Annex B (informative) Compressive forces in the simulated short-circuit current test . 51
Annex C (informative) Characterisation of the elastic and damping properties
Stiffness-Damping Method . 52
Annex D (informative) Verification of vibration behaviour of the bundle/spacer system . 54
D.1 General . 54
D.2 Aeolian vibration . 54
D.3 Subspan oscillation . 55
Annex E (informative) Description of HT conductors as given in
CIGRE TB 695‑2017 [7] . 56
Bibliography . 57
Figure 1 – Test arrangements for longitudinal slip tests . 18
Figure 2 – Test arrangement for torsional slip tests . 22
Figure 3 – Test arrangement for the spring force test at room temperature . 24
Figure 4 – Test arrangement for permanent load test on conical washers . 25
Figure 5 – Test arrangements for simulated short-circuit current tests . 30
Figure 6 – Test arrangements for compression and tension test . 32
Figure 7 – Typical logaritmic decrement graph . 36
Figure 8 – Sketch of longitudinal displacement test . 38
Figure 9 – Sketch of vertical displacement test . 39
Figure 10 – Sketch of conical displacement test . 39
Figure 11 – Sketch of transverse horizontal displacement test . 40
Figure 12 – Test arrangements for subspan oscillation tests . 43
Figure 13 – Test arrangement for aeolian vibration test . 45
Figure C.1 – Rotation of spacer arm around the centre of the hinge . 52
Figure C.2 – Vector representation of formula C.2 . 53
Table 1 – Tests on spacers . 13
Table 2 – Tests on elastomers . 47
– 4 – IEC 61854:2020 RLV © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
OVERHEAD LINES –
REQUIREMENTS AND TESTS FOR SPACERS
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
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.
International Standard IEC 61854 has been prepared by IEC technical committee 11:
Overhead lines.
This second edition cancels and replaces the first edition published in 1998. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Consider the application of spacers on high temperature conductors specifying additional
high temperature tests in clamp slip tests and for the characterization of elastic and
damping properties;
b) Specify as far as possible test parameters and acceptance values;
c) Avoid as far as possible the alternative procedures for the same test;
d) Introduce a simpler test device for the simulated short circuit current test;
e) Introduce test at low temperature on fastener components such as break away bolts and
conical spring washers;
f) Prescribe a different procedure for subspan oscillation tests on spacers equipped with
clamps having rod attachments;
g) Modify the test procedure for the aeolian vibration tests;
h) Prescribe a different procedure for aeolian vibration tests on spacers equipped with clamps
having rod attachments;
i) Re-edit all the figures in order to make them more clear and homogeneous;
j) Introduce an additional test device for the simulated short circuit current test.
The text of this standard is based on the following documents:
FDIS Report on voting
11/265/FDIS 11/272/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 61854:2020 RLV © IEC 2020
OVERHEAD LINES –
REQUIREMENTS AND TESTS FOR SPACERS
1 Scope
This document applies to spacers for conductor bundles of overhead lines. It covers rigid
spacers, flexible spacers and spacer dampers.
It does not apply to interphase spacers, hoop spacers and bonding spacers.
NOTE This document is written to cover the line design practices and spacers most commonly used at the time of
writing. There may be other spacers available for which the specific tests reported in this document may not be
applicable.
In many some cases, test procedures and test values are left to agreement between
purchaser and supplier and are stated in the procurement contract. The purchaser is best able
to evaluate the intended service conditions, which should be the basis for establishing the test
severity.
In Annex A, the minimum technical details to be agreed between purchaser and supplier are
listed.
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 60050(466):1990, International Electrotechnical vocabulary (IEV) – Chapter 466:
Overhead lines
IEC 60888:1987, Zinc-coated steel wires for stranded conductors
IEC 61284:1997, Overhead lines – Requirements and tests for fittings
ISO 34-1:19942015, Rubber, vulcanized or thermoplastic – Determination of tear strength –
Part 1: Trouser, angle and crescent test pieces
ISO 34-2:19962015, Rubber, vulcanized or thermoplastic – Determination of tear strength –
Part 2: Small (Delft) test pieces
ISO 37:19942017, Rubber, vulcanized or thermoplastic – Determination of tensile stress-
strain properties
ISO 188:19822011, Rubber, vulcanized or thermoplastic – Accelerated ageing or heat
resistance tests
ISO 812:19912017, Rubber, vulcanized or thermoplastic – Determination of low-temperature
brittleness
ISO 815:1991, Rubber, vulcanized or thermoplastic – Determination of compression set at
ambient, elevated or low temperatures
ISO 815-1:2014, Rubber, vulcanized or thermoplastic – Determination of compression set –
Part 1: At ambient or elevated temperatures
ISO 815-2:2014, Rubber, vulcanized or thermoplastic – Determination of compression set –
Part 2: At low temperatures
ISO 868:19852003, Plastics and ebonite – Determination of indentation hardness by means of
a durometer (Shore hardness)
ISO 1183:1987, Plastics – Methods for determining the density and relative density of non-
cellular plastics
ISO 1183-1:2019, Plastics — Methods for determining the density of non-cellular plastics —
Part 1: Immersion method, liquid pycnometer method and titration method
ISO 1431-1:19892012, Rubber, vulcanized or thermoplastic – Resistance to ozone cracking –
Part 1: Static and dynamic strain testing
ISO 1461:2009, Hot dip galvanized coatings on fabricated ferrous products iron and steel
1)
articles – Specifications and test methods
ISO 1817:19852015, Rubber, vulcanized or thermoplastic – Determination of the effect of
liquids
ISO 2781:19882018, Rubber, vulcanized or thermoplastic – Determination of density
ISO 2859-1:19891999/AMD1:2011, Sampling procedures for inspection by attributes – Part 1:
Sampling plans schemes indexed by acceptable quality level limit (AQL) for lot-by-lot
inspection
ISO 2859-2:1985, Sampling procedures for inspection by attributes – Part 2: Sampling plans
indexed by limiting quality level (LQ) for isolated lot inspection
ISO 2921:19822011, Rubber, vulcanized – Determination of low-temperature characteristics
retraction (TR test) – Temperature-retraction procedure (TR test)
ISO 3417:1991, Rubber – Measurement of vulcanization characteristics with the oscillating
disc curemeter
ISO 3951:1989, Sampling procedures and charts for inspection by variables for percent
nonconforming
ISO 3951-1:2013, Sampling procedures for inspection by variables -- Part 1: Specification for
single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a
single quality characteristic and a single AQL
ISO 3951-2:2013, Sampling procedures for inspection by variables -- Part 2: General
specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot
inspection of independent quality characteristics
ISO 4649:19852017, Rubber, vulcanized or thermoplastic – Determination of abrasion
resistance using a rotating cylindrical drum device
___________
1)
To be published.
– 8 – IEC 61854:2020 RLV © IEC 2020
ISO 4662:19862017, Rubber, vulcanized or thermoplastic – Determination of rebound
resilience of vulcanizates
ISO 6502-2:2018, Rubber – Measurement of vulcanization characteristics using curemeters –
Part 2: Oscillating disc curemeter
ISO 9001:2015, Quality management systems – Requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-466 apply as
well as the following.
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
rigid spacer
spacer allowing no relative movement between the subconductors at the spacer location
3.2
flexible spacer
spacer allowing relative movements between the subconductors at the spacer location
3.3
spacer system
complex of spacers and the relevant in-span distribution
3.4
high temperature conductors
HTC
conductors which are designed to have a maximum continuous operating temperature over
95 °C
Note 1 to entry: HTCa: conductors using annealed wires; HTCna: conductors using non-annealed wires.
3.5
maximum continuous operating temperature
conductor temperature specified by the manufacturer and measured at the outer wire layers
4 General requirements
4.1 Design
The spacer shall be designed as to:
– maintain subconductor spacing (at spacer locations), within any prescribed limits, under all
conditions of service excluding short-circuit currents;
– prevent, in subspans between spacers, physical contact between subconductors, except
during the passage of short circuit currents when the possibility of contact is accepted
provided that the specified spacing is restored immediately following fault clearance;
– withstand mechanical loads imposed on the spacer during installation, maintenance and
service (including short circuit conditions) without any component failure or unacceptable
permanent deformation;
– avoid damage to the subconductor under specified service conditions;
– be free from unacceptable levels of corona and radio interference under specified service
conditions;
– be suitable for safe and easy installation. For the bolted and latching clamp the design
shall retain all parts when opened for attachment to the conductor;
– ensure that individual components will not become loose in service;
– be capable of being removed and re-installed on the subconductors without damage to the
spacer or subconductors;
– maintain its function over the entire service temperature range;
– avoid audible noise.
NOTE Other desirable characteristics, which are not essential to the basic functions of the
spacer but which may be advantageous to the purchaser, include:
• verification of proper installation from the ground,
• ease of installation and removal from energized lines
Detailed information on design, best practice and experience of spacers and spacer dampers
is given in [6] .
4.2 Materials
4.2.1 General
Spacers shall be made of any materials suitable for their purpose. Unless additional
requirements are stated, the material shall conform to the requirements of IEC 61284.
4.2.2 Non-metallic materials
In addition to the requirements of IEC 61284, the conductivity of the various non-metallic
components shall be such that when properly installed
– potential differences between metallic components do not cause damage due to discharge;
– any current flow between subconductors does not degrade spacer materials .
– line current including short circuit current and any current flow through the spacer do not
degrade spacer components.
4.3 Mass, dimensions and tolerances
Spacer mass and significant dimensions, including appropriate tolerances, shall be shown on
contract drawings.
NOTE Tolerances applied to the mass and to the dimensions should ensure that the spacers
meet their specified mechanical and electrical requirements.
4.4 Protection against corrosion
In addition to the applicable requirements of IEC 61284, stranded steel wires, if used, shall be
protected against corrosion in accordance with IEC 60888.
4.5 Manufacturing appearance and finish
The spacers shall be free of defects and irregularities; all outside surfaces shall be smooth
and all edges and corners well-rounded.
___________
Numbers in square brackets refer to the Bibliography.
– 10 – IEC 61854:2020 RLV © IEC 2020
4.6 Marking
The fitting marking requirements of IEC 61284 shall be applied to all clamp assemblies
including those using breakaway bolts.
Correct position of the top of the spacer (for example arrows pointing upward), if necessary,
shall also be provided.
4.7 Installation instructions
The supplier shall provide a clear and complete description of the installation procedure and,
if required, the in-span location of the spacers.
The supplier shall make available any special installation tool that is required.
4.8 Specimen
All tests described in this document are based on bolted clamps and clamps with helical
fixation. If other types of clamps are tested, the clamps should be installed according the
suppliers installation instruction.
5 Quality assurance
A quality assurance programme taking into account the requirements of this document can be
used by agreement between the purchaser and the supplier to verify the quality of the spacers
during the manufacturing process.
Detailed information on the use of quality assurance is given in the following ISO standards
*
ISO 9000-1 [1]; ISO 9001 [2]; ISO 9002 [3]; ISO 9003 [4] and ISO 9004-1 [5] a system as per
ISO 9001 or similar.
It is recommended that test and measuring equipment used to verify compliance to this
document is routinely maintained and calibrated in accordance with a relevant quality
standard.
6 Classification of tests
6.1 Type tests
6.1.1 General
Type tests are intended to establish design characteristics. They are normally made once and
repeated only when the design or the material of the spacer is changed. The results of type
tests are recorded as evidence of compliance with design requirements.
6.1.2 Application
Spacers shall be subjected to type tests as per Table 1. Each type test shall be performed on
three samples which are identical, in all essential respects, with the spacers to be supplied
under contract to the purchaser. All units shall pass the tests.
The spacers used for tests during which no damage occurs to the units or their components
may be used in subsequent tests.
___________
*
Figures in square brackets refer to the bibliography.
NOTE The unit subjected to type tests can be either a complete spacer or a component of the spacer as
appropriate to the test.
6.2 Sample tests
6.2.1 General
Sample tests are required to verify that the spacers meet the performance specifications of
the type test samples. In addition, they are intended to verify the quality of materials and
workmanship.
6.2.2 Application
Spacers shall be subjected to sample tests as per Table 1. The samples to be tested shall be
selected at random from the lot offered for acceptance. The purchaser has the right to make
the selection.
The spacers used for tests during which no damage occurs to the units or their components
may be used in subsequent tests.
NOTE The unit subjected to sample tests can be either a complete spacer or a component of
the spacer as appropriate to the test.
6.2.3 Sampling and acceptance criteria
The sampling plan procedures according to ISO 2859-1 and ISO 2859-2 (inspection by
attributes) and ISO 3951 (inspection by variables) and the detailed procedures (inspection
level, AQL, single, double or multiple sampling, etc.) shall be agreed between purchaser and
supplier for each different attribute or variable.
NOTE Sampling inspection by variables is an acceptance sampling procedure to be used in
place of inspection by attributes when it is more appropriate to measure on some continuous
scale the characteristic(s) under consideration. In the case of failure load tests and similar
expensive tests, better discrimination between acceptable quality and objective quality is
available with acceptance sampling by variables than by attributes for the same sample size.
The purpose of the sampling process may also be important in the choice between a variables
or attributes plan. For example, a customer may choose to use an attributes acceptance
sampling plan to assure that parts in a shipment lot are within a required dimensional
tolerance; the manufacturer may make measurements under a variables sampling plan of the
same dimensions because of concern with gradual trends or changes which may affect the
ability to provide shipment lots which meet the AQL.
6.3 Routine tests
6.3.1 General
Routine tests are intended to prove conformance of spacers to specific requirements and are
made on every spacer. The tests shall not damage the spacers.
6.3.2 Application and acceptance criteria
Whole lots of spacers may be subjected to routine tests. Any spacer which does not conform
to the requirements shall be discarded.
6.4 Table of tests to be applied
Table 1 indicates the tests which shall be performed. These are marked with an "X" in the
table.
– 12 – IEC 61854:2020 RLV © IEC 2020
However, the purchaser may specify additional tests which are included in the table and
marked with an "O".
Units or components damaged during the tests shall be excluded from the delivery to the
customer.
Table 1 – Tests on spacers
Spacer damper Flexible spacer Rigid spacer
Clause Test
Type Sample Routine Type Sample Routine Type Sample Routine
test test test test test test test test test
7.1 Visual examination X X O X X O X X O
7.2 Verification of dimensions, material and X X O X X O X X O
mass
1) 1) 1) 1) 1) 1)
7.3 Corrosion protection tests X X X X X X
7.4 Non-destructive tests O O O O O O O O O
7.5 Mechanical tests
7.5.1 – clamp slip tests X O X O X O
7.5.2 – breakaway bolt test X X X X X X
7.5.2 – tests on bolt sets X X X X X X
7.5.3 – clamp bolt tightening test X X X X X X
7.5.3 – simulated short circuit current test X O X O X O
and compression and tension tests
7.5.4 – characterisation of the elastic and X O O O
damping properties
7.5.5 – flexibility tests X O X O
7.5.6 – fatigue tests X O
1) 1)
7.6 Tests to characterise elastomers X O X O
7.7 Electrical tests
7.7.1 – corona and radio interference voltage X X X
(RIV) tests
1) 1) 1)
7.7.2 – electrical resistance test X O X O O
7.8 Verification of vibration behaviour of the
bundle/spacer system
2)
D.2 – aeolian vibration O O
D.3 – subspan oscillation O O
1)
If applicable.
2)
When used in conjunction with vibration dampers.
NOTE The supplier should state in the tender quality plan, or other tender documentation, which testing is already complete (i.e: which type test) and which tests
(sample or routine) are included in the tender, subject to the approval or change required by the purchaser.
– 14 – IEC 61854:2020 RLV © IEC 2020
7 Test methods
7.1 Visual examination
Type tests shall include visual examination to ascertain conformity of the spacers, in all
essential respects, with the manufacturing or contract drawings. Deviations from the drawings
shall be subject to the approval of the purchaser and shall be appropriately documented as an
agreed concession.
Sample tests and, if required, routine tests shall include visual examination to ensure
conformity of manufacturing process, shape, coating and surface finish of the spacer with the
contract drawings. Particular attention shall be given to the markings required and to the
finish of surfaces which come into contact with the conductor.
The sample test procedures and acceptance criteria shall be agreed between purchaser and
supplier.
For spacers subject to corona type tests, the sample test shall include a comparison of shape
and surface finish with one of the corona type test samples when specified or agreed by the
purchaser.
7.2 Verification of dimensions, materials and mass
Type, sample and, if required, routine tests shall include verification of dimensions to ensure
that spacers are within the dimensional tolerances stated on contract drawings. The
purchaser may choose to witness the measurement of selected dimensions or may inspect the
supplier's documentation when this is available.
Type, sample and, if required, routine tests shall also include verification of materials to
ensure that they are in accordance with contract drawings and documents. This verification
shall normally be carried out by the purchaser inspecting the supplier's documentation relating
to material specifications, certificates of conformity or other quality documentation.
The total mass of the spacer complete with all its components shall comply with the mass
shown on the contract drawing (within given tolerances).
7.3 Corrosion protection test
7.3.1 Hot dip galvanized components (other than stranded galvanized steel wires)
Hot dip galvanized components other than stranded galvanized steel wires shall be tested in
accordance with the requirements specified in: ISO 1461.
The coating thicknesses shall conform to Tables 23 and 34 unless otherwise agreed between
purchaser and supplier. However, for the purpose of this document, Tables 23 and 34 of
ISO 1461:2009 shall apply to the following categories of items (and not to the categories
specified in ISO 1461).
Table 23 of ISO 1461:2009: coating thickness on all samples except:
– washers;
– threaded components;
– small parts which are centrifuged (significant surface area < 1 000 mm ).
Table 34 of ISO 1461:2009 coating thickness on
– washers;
– threaded components;
– small parts which are centrifuged (significant surface area < 1 000 mm ).
7.3.2 Ferrous components protected from corrosion by methods other than hot dip
galvanizing
Ferrous components protected from corrosion by methods other than hot dip galvanizing shall
be tested in accordance with the requirement of the relevant IEC/ISO standards, as agreed
between purchaser and supplier.
7.3.3 Stranded galvanized steel wires
Stranded galvanized steel wires shall be tested in accordance with the requirements specified
in IEC 60888.
7.3.4 Corrosion caused by non-metallic components
By agreement between purchaser and supplier, evidence of non-corrosion compatibility
between the elastomer and the conductor or spacer components, as appropriate, shall be
demonstrated by a corrosion test or by suitable service experience. Alternatively, and where
appropriate, the purchaser may specify for each subassembly containing an elastomer, a
range of electrical resistance which provides adequate conductivity for electrical charging but
minimizes galvanic action.
NOTE Non-metallic components, especially elastomeric elements lining a spacer clamp or providing the flexibility
and damping in a spacer damper, are commonly made electrically conducting to avoid any problems that might
otherwise arise from the capacitive charging of the arms or body of the spacer. Carbon is frequently used in
elastomer formulations, both to achieve the desired stiffness and damping, and to provide electrical conductivity.
However, carbon in contact with aluminium may lead to severe galvanic corrosion of the latter in a polluted
environment. Other constituents of non-metallic components, such as chlorides, free sulphur, etc. may also have
corrosive effects. Some constituents of the non-metallic components, such as chlorides, free sulphur, etc., may
have corrosion effects.
The combination of the nature of the rubber, the pollution and the electrolyte are responsible for a corrosion
process.
7.4 Non-destructive tests
The purchaser shall specify or agree to relevant test methods (ISO or other) and acceptance
criteria. Examples of non-destructive tests are as follows:
– magnetic test;
– eddy current test;
– radiographic test;
– ultrasonic test;
– proof load test;
– dye penetrant test;
– hardness test.
7.5 Mechanical tests
7.5.1 Clamp slip tests
7.5.1.1 General
The tests shall be performed using the conductor for which the clamps are intended. The
conductor shall be "as new", i.e. free of any deterioration or damage. The minimum length of
the test conductor between its terminating fittings shall be, with the exception of the test in
– 16 – IEC 61854:2020 RLV © IEC 2020
clause 7.5.1.2 B), 4 m. The conductor shall be tensioned to 20 % of its rated tensile strength
before the installation of the clamps to be tested.
Clamps shall be installed on an unused portion of conductor for each test.
Precautions shall be taken to avoid birdcaging of the conductor.
The clamps shall be tested individually. The clamp shall be installed in accordance with the
supplier's instructions. In the case of breakaway bolts, the installation torque shall be the
design value minus the tolerance agreed between purchaser and supplier (see 7.5.3). The
clamp shall be installed in accordance with the supplier's instructions. In the case of
breakaway bolts or break away caps, the breakaway portion shall be removed and the torque
has to be applied to the lower head with a calibrated torque wrench.
The installation torque shall be the nominal break away torque minus the tolerance as
specified by the supplier.
NOTE The use of other conductor, conductor lengths and tensions can be agreed between
purchaser and supplier.
7.5.1.2 Longitudinal slip test
A) By means of a suitable device (see figure 1a), a load coaxial to the conductor shall be
applied to the clamp.
The load shall be gradually increased (not faster than 100 N/s) until it reaches the
specified minimum slip load value. This load shall be kept constant for 60 s. Then the load
shall
be gradually increased until slippage of the clamp occurs. The slip load value shall be
recorded.
For metal surface clamps, slip shall be considered as having occurred when a movement
of the clamp on the conductor of 1,0 mm is measured.
NOTE – The following values for rubber-lined clamps and clamps using helical rods are given for reference:
– rubber-lined clamp: 2,5 mm;
– clamp using helical rods: 12,0 mm.
• Acceptance criteria
No slippage shall occur at or below the minimum specified value. If both minimum and
maximum slip requirements are stated, the slip shall occur between those values. Surface
flattening of the outer strands of the conductor is acceptable.
B) An alternative test arrangement which evaluates the performance of the whole spacer
assembly under simulated broken conductor conditions, as well as clamp slip, is shown in
figure 1b.
NOTE – The effects imposed by the two test methods A) and B) are not equivalent.
For a bundle of N subconductors, N-1 subconductors shall be tensioned. A spacer shall be
mounted on the subconductors and a longitudinal force shall be applied to the untensioned
subconductor.
The load shall be gradually increased (not faster than 100 N/s) until it reaches the
specified minimum slip load value. This load shall be kept constant for 60 s. Then the load
shall be gradually increased until slippage of the clamp occurs. The slip load value shall
be recorded.
For metal surface clamps, slip shall be considered as having occurred when a movement
of the clamp on the conductor of 1,0 mm is measured.
NOTE – The following values for rubber-lined clamps and clamps using helical rods are given for reference:
– rubber-lined clamp: 2,5 mm;
– clamp using helical rods: 12,0 mm.
• Acceptance criteria
The slip force of the clamp on the subconductor or the failure load of the spacer shall not
be less than the minimum specified value. In addition, if required by the purchaser, the
longitudinal movement of the
...
IEC 61854 ®
Edition 2.0 2020-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Overhead lines – Requirements and tests for spacers
Lignes aériennes – Exigences et essais applicables aux entretoises
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IEC 61854 ®
Edition 2.0 2020-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Overhead lines – Requirements and tests for spacers
Lignes aériennes – Exigences et essais applicables aux entretoises
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.240.20 ISBN 978-2-8322-7798-0
– 2 – IEC 61854:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 General requirements . 8
4.1 Design . 8
4.2 Materials . 9
4.2.1 General . 9
4.2.2 Non-metallic materials . 9
4.3 Mass, dimensions and tolerances . 9
4.4 Protection against corrosion . 9
4.5 Manufacturing appearance and finish . 9
4.6 Marking . 9
4.7 Installation instructions . 9
4.8 Specimen . 9
5 Quality assurance . 10
6 Classification of tests. 10
6.1 Type tests . 10
6.1.1 General . 10
6.1.2 Application . 10
6.2 Sample tests . 10
6.2.1 General . 10
6.2.2 Application . 10
6.2.3 Sampling and acceptance criteria . 11
6.3 Routine tests. 11
6.3.1 General . 11
6.3.2 Application and acceptance criteria . 11
6.4 Table of tests to be applied . 11
7 Test methods . 13
7.1 Visual examination . 13
7.2 Verification of dimensions, materials and mass . 13
7.3 Corrosion protection test . 13
7.3.1 Hot dip galvanized components (other than stranded galvanized steel
wires) . 13
7.3.2 Ferrous components protected from corrosion by methods other than
hot dip galvanizing . 14
7.3.3 Stranded galvanized steel wires . 14
7.3.4 Corrosion caused by non-metallic components . 14
7.4 Non-destructive tests . 14
7.5 Mechanical tests . 14
7.5.1 Clamp slip tests . 14
7.5.2 Tests on bolt sets . 19
7.5.3 Simulated short-circuit current test and compression and tension tests . 21
7.5.4 Characterisation of the elastic and damping properties . 27
7.5.5 Flexibility tests . 31
7.5.6 Fatigue tests . 33
7.6 Tests to characterise elastomers . 36
7.6.1 General . 36
7.6.2 Tests . 36
7.6.3 Ozone resistance test . 36
7.7 Electrical tests . 38
7.7.1 Corona and radio interference voltage (RIV) tests. 38
7.7.2 Electrical resistance test . 38
7.8 Verification of vibration behaviour of the bundle/spacer system . 39
Annex A (normative) Minimum technical details to be agreed between purchaser and
supplier . 40
Annex B (informative) Compressive forces in the simulated short-circuit current test . 41
Annex C (informative) Characterisation of the elastic and damping properties
Stiffness-Damping Method . 42
Annex D (informative) Verification of vibration behaviour of the bundle/spacer system . 44
D.1 General . 44
D.2 Aeolian vibration . 44
D.3 Subspan oscillation . 45
Annex E (informative) Description of HT conductors as given in
CIGRE TB 695‑2017 [7] . 46
Bibliography . 47
Figure 1 – Test arrangements for longitudinal slip tests . 16
Figure 2 – Test arrangement for torsional slip tests . 19
Figure 3 – Test arrangement for the spring force test at room temperature . 20
Figure 4 – Test arrangement for permanent load test on conical washers . 21
Figure 5 – Test arrangements for simulated short-circuit current tests . 25
Figure 6 – Test arrangements for compression and tension test . 26
Figure 7 – Typical logaritmic decrement graph . 30
Figure 8 – Sketch of longitudinal displacement test . 32
Figure 9 – Sketch of vertical displacement test . 32
Figure 10 – Sketch of conical displacement test . 32
Figure 11 – Sketch of transverse horizontal displacement test . 33
Figure 12 – Test arrangements for subspan oscillation tests . 34
Figure 13 – Test arrangement for aeolian vibration test . 36
Figure C.1 – Rotation of spacer arm around the centre of the hinge . 42
Figure C.2 – Vector representation of formula C.2 . 43
Table 1 – Tests on spacers . 12
Table 2 – Tests on elastomers . 37
– 4 – IEC 61854:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
OVERHEAD LINES –
REQUIREMENTS AND TESTS FOR SPACERS
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
Publications.
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.
International Standard IEC 61854 has been prepared by IEC technical committee 11:
Overhead lines.
This second edition cancels and replaces the first edition published in 1998. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) Consider the application of spacers on high temperature conductors specifying additional
high temperature tests in clamp slip tests and for the characterization of elastic and
damping properties;
b) Specify as far as possible test parameters and acceptance values;
c) Avoid as far as possible the alternative procedures for the same test;
d) Introduce a simpler test device for the simulated short circuit current test;
e) Introduce test at low temperature on fastener components such as break away bolts and
conical spring washers;
f) Prescribe a different procedure for subspan oscillation tests on spacers equipped with
clamps having rod attachments;
g) Modify the test procedure for the aeolian vibration tests;
h) Prescribe a different procedure for aeolian vibration tests on spacers equipped with clamps
having rod attachments;
i) Re-edit all the figures in order to make them more clear and homogeneous;
j) Introduce an additional test device for the simulated short circuit current test.
The text of this standard is based on the following documents:
FDIS Report on voting
11/265/FDIS 11/272/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 61854:2020 © IEC 2020
OVERHEAD LINES –
REQUIREMENTS AND TESTS FOR SPACERS
1 Scope
This document applies to spacers for conductor bundles of overhead lines. It covers rigid
spacers, flexible spacers and spacer dampers.
It does not apply to interphase spacers, hoop spacers and bonding spacers.
NOTE This document is written to cover the line design practices and spacers most commonly used at the time of
writing. There may be other spacers available for which the specific tests reported in this document may not be
applicable.
In some cases, test procedures and test values are left to agreement between purchaser and
supplier and are stated in the procurement contract. The purchaser is best able to evaluate
the intended service conditions, which should be the basis for establishing the test severity.
In Annex A, the minimum technical details to be agreed between purchaser and supplier are
listed.
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 60050(466):1990, International Electrotechnical vocabulary (IEV) – Chapter 466:
Overhead lines
IEC 60888:1987, Zinc-coated steel wires for stranded conductors
IEC 61284:1997, Overhead lines – Requirements and tests for fittings
ISO 34-1:2015, Rubber, vulcanized or thermoplastic – Determination of tear strength – Part 1:
Trouser, angle and crescent test pieces
ISO 34-2:2015, Rubber, vulcanized or thermoplastic – Determination of tear strength – Part 2:
Small (Delft) test pieces
ISO 37:2017, Rubber, vulcanized or thermoplastic – Determination of tensile stress-strain
properties
ISO 188:2011, Rubber, vulcanized or thermoplastic – Accelerated ageing or heat resistance
tests
ISO 812:2017, Rubber, vulcanized or thermoplastic – Determination of low-temperature
brittleness
ISO 815-1:2014, Rubber, vulcanized or thermoplastic – Determination of compression set –
Part 1: At ambient or elevated temperatures
ISO 815-2:2014, Rubber, vulcanized or thermoplastic – Determination of compression set –
Part 2: At low temperatures
ISO 868:2003, Plastics and ebonite – Determination of indentation hardness by means of a
durometer (Shore hardness)
ISO 1183-1: 2019, Plastics — Methods for determining the density of non-cellular plastics —
Part 1: Immersion method, liquid pycnometer method and titration method
ISO 1431-1:2012, Rubber, vulcanized or thermoplastic – Resistance to ozone cracking –
Part 1: Static and dynamic strain testing
ISO 1461:2009, Hot dip galvanized coatings on fabricated iron and steel articles –
Specifications and test methods
ISO 1817:2015, Rubber, vulcanized or thermoplastic – Determination of the effect of liquids
ISO 2781:2018, Rubber, vulcanized or thermoplastic – Determination of density
ISO 2859-1:1999/AMD1: 2011, Sampling procedures for inspection by attributes – Part 1:
Sampling schemes indexed by acceptable quality limit (AQL) for lot-by-lot inspection
ISO 2859-2:1985, Sampling procedures for inspection by attributes – Part 2: Sampling plans
indexed by limiting quality level (LQ) for isolated lot inspection
ISO 2921:2011, Rubber, vulcanized – Determination of low-temperature retraction (TR test)
ISO 3951-1:2013, Sampling procedures for inspection by variables -- Part 1: Specification for
single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a
single quality characteristic and a single AQL
ISO 3951-2:2013, Sampling procedures for inspection by variables -- Part 2: General
specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot
inspection of independent quality characteristics
ISO 4649:2017, Rubber, vulcanized or thermoplastic – Determination of abrasion resistance
using a rotating cylindrical drum device
ISO 4662:2017, Rubber, vulcanized or thermoplastic – Determination of rebound resilience
ISO 6502-2:2018, Rubber – Measurement of vulcanization characteristics using curemeters –
Part 2: Oscillating disc curemeter
ISO 9001:2015, Quality management systems – Requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-466 apply as
well as the following.
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
– 8 – IEC 61854:2020 © IEC 2020
3.1
rigid spacer
spacer allowing no relative movement between the subconductors at the spacer location
3.2
flexible spacer
spacer allowing relative movements between the subconductors at the spacer location
3.3
spacer system
complex of spacers and the relevant in-span distribution
3.4
high temperature conductors
HTC
conductors which are designed to have a maximum continuous operating temperature over
95 °C
Note 1 to entry: HTCa: conductors using annealed wires; HTCna: conductors using non-annealed wires.
3.5
maximum continuous operating temperature
conductor temperature specified by the manufacturer and measured at the outer wire layers
4 General requirements
4.1 Design
The spacer shall be designed as to:
– maintain subconductor spacing (at spacer locations), within any prescribed limits, under all
conditions of service excluding short-circuit currents;
– prevent, in subspans between spacers, physical contact between subconductors, except
during the passage of short circuit currents when the possibility of contact is accepted
provided that the specified spacing is restored immediately following fault clearance;
– withstand mechanical loads imposed on the spacer during installation, maintenance and
service (including short circuit conditions) without any component failure or unacceptable
permanent deformation;
– avoid damage to the subconductor under specified service conditions;
– be free from unacceptable levels of corona and radio interference under specified service
conditions;
– be suitable for safe and easy installation. For the bolted and latching clamp the design
shall retain all parts when opened for attachment to the conductor;
– ensure that individual components will not become loose in service;
– be capable of being removed and re-installed on the subconductors without damage to the
spacer or subconductors;
– maintain its function over the entire service temperature range;
– avoid audible noise.
Other desirable characteristics, which are not essential to the basic functions of the
spacer but which may be advantageous to the purchaser, include:
• verification of proper installation from the ground,
• ease of installation and removal from energized lines
Detailed information on design, best practice and experience of spacers and spacer dampers
is given in [6] .
4.2 Materials
4.2.1 General
Spacers shall be made of any materials suitable for their purpose. Unless additional
requirements are stated, the material shall conform to the requirements of IEC 61284.
4.2.2 Non-metallic materials
In addition to the requirements of IEC 61284, the conductivity of the various non-metallic
components shall be such that when properly installed
– potential differences between metallic components do not cause damage due to discharge;
– line current including short circuit current and any current flow through the spacer do not
degrade spacer components
4.3 Mass, dimensions and tolerances
Spacer mass and significant dimensions, including appropriate tolerances, shall be shown on
contract drawings.
Tolerances applied to the mass and to the dimensions should ensure that the spacers meet
their specified mechanical and electrical requirements.
4.4 Protection against corrosion
In addition to the applicable requirements of IEC 61284, stranded steel wires, if used, shall be
protected against corrosion in accordance with IEC 60888.
4.5 Manufacturing appearance and finish
The spacers shall be free of defects and irregularities; all outside surfaces shall be smooth
and all edges and corners well-rounded.
4.6 Marking
The fitting marking requirements of IEC 61284 shall be applied to all clamp assemblies
including those using breakaway bolts.
Correct position of the top of the spacer (for example arrows pointing upward), if necessary,
shall also be provided.
4.7 Installation instructions
The supplier shall provide a clear and complete description of the installation procedure and,
if required, the in-span location of the spacers.
The supplier shall make available any special installation tool that is required.
4.8 Specimen
All tests described in this document are based on bolted clamps and clamps with helical
fixation. If other types of clamps are tested, the clamps should be installed according the
suppliers installation instruction.
___________
Numbers in square brackets refer to the Bibliography.
– 10 – IEC 61854:2020 © IEC 2020
5 Quality assurance
A quality assurance programme taking into account the requirements of this document can be
used by agreement between the purchaser and the supplier to verify the quality of the spacers
during the manufacturing process.
Detailed information on the use of quality assurance is given in a system as per ISO 9001 or
similar.
It is recommended that test and measuring equipment used to verify compliance to this
document is routinely maintained and calibrated in accordance with a relevant quality
standard.
6 Classification of tests
6.1 Type tests
6.1.1 General
Type tests are intended to establish design characteristics. They are normally made once and
repeated only when the design or the material of the spacer is changed. The results of type
tests are recorded as evidence of compliance with design requirements.
6.1.2 Application
Spacers shall be subjected to type tests as per Table 1. Each type test shall be performed on
three samples which are identical, in all essential respects, with the spacers to be supplied
under contract to the purchaser. All units shall pass the tests.
The spacers used for tests during which no damage occurs to the units or their components
may be used in subsequent tests.
NOTE The unit subjected to type tests can be either a complete spacer or a component of the spacer as
appropriate to the test.
6.2 Sample tests
6.2.1 General
Sample tests are required to verify that the spacers meet the performance specifications of
the type test samples. In addition, they are intended to verify the quality of materials and
workmanship.
6.2.2 Application
Spacers shall be subjected to sample tests as per Table 1. The samples to be tested shall be
selected at random from the lot offered for acceptance. The purchaser has the right to make
the selection.
The spacers used for tests during which no damage occurs to the units or their components
may be used in subsequent tests.
The unit subjected to sample tests can be either a complete spacer or a component of the
spacer as appropriate to the test.
6.2.3 Sampling and acceptance criteria
The sampling plan procedures according to ISO 2859-1 and ISO 2859-2 (inspection by
attributes) and ISO 3951 (inspection by variables) and the detailed procedures (inspection
level, AQL, single, double or multiple sampling, etc.) shall be agreed between purchaser and
supplier for each different attribute or variable.
Sampling inspection by variables is an acceptance sampling procedure to be used in place of
inspection by attributes when it is more appropriate to measure on some continuous scale the
characteristic(s) under consideration. In the case of failure load tests and similar expensive
tests, better discrimination between acceptable quality and objective quality is available with
acceptance sampling by variables than by attributes for the same sample size.
The purpose of the sampling process may also be important in the choice between a variables
or attributes plan. For example, a customer may choose to use an attributes acceptance
sampling plan to assure that parts in a shipment lot are within a required dimensional
tolerance; the manufacturer may make measurements under a variables sampling plan of the
same dimensions because of concern with gradual trends or changes which may affect the
ability to provide shipment lots which meet the AQL.
6.3 Routine tests
6.3.1 General
Routine tests are intended to prove conformance of spacers to specific requirements and are
made on every spacer. The tests shall not damage the spacers.
6.3.2 Application and acceptance criteria
Whole lots of spacers may be subjected to routine tests. Any spacer which does not conform
to the requirements shall be discarded.
6.4 Table of tests to be applied
Table 1 indicates the tests which shall be performed. These are marked with an "X" in the
table.
However, the purchaser may specify additional tests which are included in the table and
marked with an "O".
Units or components damaged during the tests shall be excluded from the delivery to the
customer.
– 12 – IEC 61854:2020 © IEC 2020
Table 1 – Tests on spacers
Spacer damper Flexible spacer Rigid spacer
Clause Test
Type Sample Routine Type Sample Routine Type Sample Routine
test test test test test test test test test
7.1 Visual examination X X O X X O X X O
7.2 Verification of dimensions, material and X X O X X O X X O
mass
1) 1) 1) 1) 1) 1)
7.3 Corrosion protection tests X X X X X X
7.4 Non-destructive tests O O O O O O O O O
7.5 Mechanical tests
7.5.1 – clamp slip tests X O X O X O
7.5.2 – tests on bolt sets X X X X X X
– simulated short-circuit current test
7.5.3 X O X O X O
and compression and tension tests
7.5.4 – characterisation of the elastic and X O O O
damping properties
7.5.5 – flexibility tests X O X O
7.5.6 – fatigue tests X O
1) 1)
7.6 Tests to characterise elastomers X O X O
7.7 Electrical tests
– corona and radio interference voltage
7.7.1 X X X
(RIV) tests
1) 1) 1)
7.7.2 – electrical resistance test X O X O O
7.8 Verification of vibration behaviour of the
bundle/spacer system
2)
D.2 – aeolian vibration O O
D.3 – subspan oscillation O O
1)
If applicable.
2)
When used in conjunction with vibration dampers.
The supplier should state in the tender quality plan, or other tender documentation, which testing is already complete (i.e: which type test) and which tests
(sample or routine) are included in the tender, subject to the approval or change required by the purchaser.
7 Test methods
7.1 Visual examination
Type tests shall include visual examination to ascertain conformity of the spacers, in all
essential respects, with the manufacturing or contract drawings. Deviations from the drawings
shall be subject to the approval of the purchaser and shall be appropriately documented as an
agreed concession.
Sample tests and, if required, routine tests shall include visual examination to ensure
conformity of manufacturing process, shape, coating and surface finish of the spacer with the
contract drawings. Particular attention shall be given to the markings required and to the
finish of surfaces which come into contact with the conductor.
The sample test procedures and acceptance criteria shall be agreed between purchaser and
supplier.
For spacers subject to corona type tests, the sample test shall include a comparison of shape
and surface finish with one of the corona type test samples when specified or agreed by the
purchaser.
7.2 Verification of dimensions, materials and mass
Type, sample and, if required, routine tests shall include verification of dimensions to ensure
that spacers are within the dimensional tolerances stated on contract drawings. The
purchaser may choose to witness the measurement of selected dimensions or may inspect the
supplier's documentation when this is available.
Type, sample and, if required, routine tests shall also include verification of materials to
ensure that they are in accordance with contract drawings and documents. This verification
shall normally be carried out by the purchaser inspecting the supplier's documentation relating
to material specifications, certificates of conformity or other quality documentation.
The total mass of the spacer complete with all its components shall comply with the mass
shown on the contract drawing (within given tolerances).
7.3 Corrosion protection test
7.3.1 Hot dip galvanized components (other than stranded galvanized steel wires)
Hot dip galvanized components other than stranded galvanized steel wires shall be tested in
accordance with the requirements specified in: ISO 1461.
The coating thicknesses shall conform to Tables 3 and 4 unless otherwise agreed between
purchaser and supplier. However, for the purpose of this document, Tables 3 and 4 of
ISO 1461:2009 shall apply to the following categories of items (and not to the categories
specified in ISO 1461).
Table 3 of ISO 1461:2009: coating thickness on all samples except:
– washers;
– threaded components;
).
– small parts which are centrifuged (significant surface area < 1 000 mm
– 14 – IEC 61854:2020 © IEC 2020
Table 4 of ISO 1461:2009 coating thickness on
– washers;
– threaded components;
– small parts which are centrifuged (significant surface area < 1 000 mm ).
7.3.2 Ferrous components protected from corrosion by methods other than hot dip
galvanizing
Ferrous components protected from corrosion by methods other than hot dip galvanizing shall
be tested in accordance with the requirement of the relevant IEC/ISO standards, as agreed
between purchaser and supplier.
7.3.3 Stranded galvanized steel wires
Stranded galvanized steel wires shall be tested in accordance with the requirements specified
in IEC 60888.
7.3.4 Corrosion caused by non-metallic components
By agreement between purchaser and supplier, evidence of non-corrosion compatibility
between the elastomer and the conductor or spacer components, as appropriate, shall be
demonstrated by a corrosion test or by suitable service experience. Alternatively, and where
appropriate, the purchaser may specify for each subassembly containing an elastomer, a
range of electrical resistance which provides adequate conductivity for electrical charging but
minimizes galvanic action.
NOTE Non-metallic components, especially elastomeric elements lining a spacer clamp or providing the flexibility
and damping in a spacer damper, are commonly made electrically conducting to avoid any problems that might
otherwise arise from the capacitive charging of the arms or body of the spacer. Carbon is frequently used in
elastomer formulations, both to achieve the desired stiffness and damping, and to provide electrical conductivity.
Some constituents of the non-metallic components, such as chlorides, free sulphur, etc., may have corrosion
effects.
The combination of the nature of the rubber, the pollution and the electrolyte are responsible for a corrosion
process.
7.4 Non-destructive tests
The purchaser shall specify or agree to relevant test methods (ISO or other) and acceptance
criteria. Examples of non-destructive tests are as follows:
– magnetic test;
– eddy current test;
– radiographic test;
– ultrasonic test;
– proof load test;
– dye penetrant test;
– hardness test.
7.5 Mechanical tests
7.5.1 Clamp slip tests
7.5.1.1 General
The tests shall be performed using the conductor for which the clamps are intended. The
conductor shall be "as new", i.e. free of any deterioration or damage. The minimum length of
the test conductor between its terminating fittings shall be 4 m. The conductor shall be
tensioned to 20 % of its rated tensile strength before the installation of the clamps to be
tested.
Clamps shall be installed on an unused portion of conductor for each test.
Precautions shall be taken to avoid birdcaging of the conductor.
The clamps shall be tested individually. The clamp shall be installed in accordance with the
supplier's instructions. In the case of breakaway bolts or break away caps, the breakaway
portion shall be removed and the torque has to be applied to the lower head with a calibrated
torque wrench.
The installation torque shall be the nominal break away torque minus the tolerance as
specified by the supplier.
The use of other conductor, conductor lengths and tensions can be agreed between
purchaser and supplier.
7.5.1.2 Longitudinal slip test
By means of a suitable device (i.e. Figure 1), a load coaxial to the conductor shall be applied
to the clamp.
The load shall be gradually increased (not faster than 100 N/s) until it reaches the following
values, unless otherwise agreed between purchaser and supplier.
– 4,0 kN for metal to metal clamps (except helical fixation);
– 1,5 kN for rubber/elastomer-lined clamps;
– 1,5 kN for clamps with helical fixation.
This load shall be kept constant for 60 s
To detect slippage colour marks shall be fixed at the interface of the clamp and conductor
respectively and at the end of helical rods, if used. Other methods are also permitted if agreed
between purchaser and supplier.
Then the load shall be gradually increased until slippage of the clamp occurs.
Slippage shall be considered as having occurred when the pulling force cannot be increased
or the movement of the clamp on the conductor is
– 2 mm for metal to metal clamp;
– 5 mm for rubber lined clamp;
– 15 mm for clamps with helical fixation.
For type test only, an additional slip test taking into account the creeping behaviour of the
conductor shall be performed.
A new clamp shall be fixed (according to 7.5.1.1) on the conductor which is tensioned to 20 %
of RTS. Then the tension shall be gradually increased (not more than 100 N/s) to 40 % of
conductor RTS and kept for 2 h at this tension load.
It is permitted to fix several clamps on the same setup to reduce expenditure of time. The
distance between the clamps shall be at least 300 mm.
Afterwards the tension shall be gradually decreased to 20 % of conductor RTS and the slip
test shall be repeated.
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