SIST EN 61897:1999

SLOVENSKI STANDARD
SIST EN 61897:1999
01-november-1999
Nadzemni vodi - Zahteve in preskusi za dušilnike vetrnih vibracij Stockbridge (IEC
61897:1998)
Overhead lines - Requirements and tests for Stockbridge type aeolian vibration dampers
Freileitungen - Anforderungen und Prüfungen für Schwingungsdämpfer Typ Stockbridge
Lignes aériennes - Exigences et essais applicables aux amortisseurs de vibrations
éoliennes Stockbridge
Ta slovenski standard je istoveten z: EN 61897:1998
ICS:
29.240.20 Daljnovodi Power transmission and
distribution lines
SIST EN 61897:1999 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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NORME
CEI
INTERNATIONALE
IEC
61897
INTERNATIONAL
Première édition
STANDARD
First edition
1998-09
Lignes aériennes –
Exigences et essais applicables aux amortisseurs
de vibrations éoliennes Stockbridge
Overhead lines –
Requirements and tests for Stockbridge type
aeolian vibration dampers
 IEC 1998 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
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Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
PRICE CODE S
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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61897 © IEC:1998 – 3 –
CONTENTS
Page
FOREWORD . 7
Clause
1 Scope . 9
2 Normative references . 9
3 Definitions. 11
4 General requirements. 11
4.1 Design . 11
4.2 Materials. 11
4.3 Mass, dimensions and tolerances. 11
4.4 Protection against corrosion . 13
4.5 Manufacturing appearance and finish . 13
4.6 Marking. 13
4.7 Installation instructions. 13
5 Quality assurance . 13
6 Classification of tests . 13
6.1 Type tests . 13
6.1.1 General. 13
6.1.2 Application . 13
6.2 Sample tests . 15
6.2.1 General. 15
6.2.2 Application . 15
6.2.3 Sampling, acceptance criteria. 15
6.3 Routine tests. 15
6.3.1 General. 15
6.3.2 Application and acceptance criteria. 15
6.4 Table of tests to be applied . 17
7 Test methods . 17
7.1 Visual examination . 17
7.2 Verification of dimensions, materials and mass . 19
7.3 Corrosion protection tests . 19
7.3.1 Hot dip galvanized components (other than messenger cable wires) . 19
7.3.2 Ferrous components protected from corrosion by methods other
than hot dip galvanizing. 19
7.3.3 Hot dip galvanized messenger cable wires. 19
7.4 Non-destructive tests . 21
7.5 Clamp slip test . 21
7.6 Breakaway bolt test. 21
7.7 Clamp bolt tightening test. 23
7.8 Attachment of weights to messenger cable . 23
7.9 Attachment of clamp to messenger cable test. 23
7.10 Corona and radio interference voltage (RIV) tests. 25

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61897 © IEC:1998 – 5 –
Clause Page
7.11 Damper performance tests . 25
7.11.1 Performance test variants. 25
7.11.2 Damper characteristic test. 25
7.11.3 Damper effectiveness evaluation . 27
7.11.3.1 Methods of evaluation. 27
7.11.3.2 Laboratory test. 29
7.11.3.3 Field test . 31
7.11.3.4 Analytical method . 33
7.12 Damper fatigue test. 33
7.12.1 Test methods . 33
7.12.2 Swept frequency method . 33
7.12.3 Resonant frequency method . 35
7.12.4 Acceptance criteria. 35
Annex A (normative)   Minimum technical details to be agreed between purchaser
and supplier . 37
Annex B (informative)  Examples of graphs relevant to damper characteristic test . 39
Annex C (normative)   Wind power input curve. 41
Bibliography . 45

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61897 © IEC:1998 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
–––––––––––
OVERHEAD LINES –
REQUIREMENTS AND TESTS FOR
STOCKBRIDGE TYPE AEOLIAN VIBRATION DAMPERS
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61897 has been prepared by IEC technical committee 11: Overhead
lines.
The text of this standard is based on the following documents:
FDIS Report on voting
11/140/FDIS 11/142/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.
Annexes A and C form an integral part of this standard.
Annex B is for information only.

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61897 © IEC:1998 – 9 –
OVERHEAD LINES –
REQUIREMENTS AND TESTS FOR
STOCKBRIDGE TYPE AEOLIAN VIBRATION DAMPERS
1 Scope
This International Standard applies to Stockbridge type aeolian vibration dampers intended for
single conductors or earth wires or conductor bundles where dampers are directly attached to
each subconductor.
The purchaser may adopt part(s) of this standard when specifying requirements for other types
of aeolian vibration dampers or for Stockbridge dampers used on conductors or cables
different from those mentioned above (e.g. optical ground wires, all dielectric self-supporting
optical cables).
In many cases, test procedures and test values are left to agreement between the purchaser
and the supplier and are stated in the procurement contract.
Annex A lists the minimum technical details to be agreed between purchaser and supplier.
Throughout this standard, the word “conductor” is used when the test applies to Stockbridge
dampers for conductors or earth wires.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this International Standard. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties to
agreements based on this International Standard are encouraged to investigate the possibility
of applying the most recent editions of the normative documents indicated below. Members of
IEC and ISO maintain registers of currently valid International Standards.
IEC 60050(466):1990, International Electrotechnical Vocabulary (IEV) – Chapter 466:
Overhead lines
IEC 61284:1997, Overhead lines – Requirements and tests for fittings
IEC 60888:1987, Zinc-coated steel wires for stranded conductors
1)
ISO 1461, — Hot dip galvanized coatings on fabricated ferrous products – Specifications
ISO 2859-1:1989, Sampling procedures for inspection by attributes – Part 1: Sampling plans
indexed by acceptable quality level (AQL) for lot-by-lot inspection
––––––––––
1)
To be published.

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61897 © IEC:1998 – 11 –
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 3951:1989, Sampling procedures and charts for inspection by variables for percent
nonconforming
3 Definitions
For the purpose of this International Standard, the definitions of the International
Electrotechnical Vocabulary (IEV) apply, in particular IEC 60050(466). Those which differ or do
not appear in the IEV are given below.
Stockbridge-type aeolian vibration damper
device comprising a messenger cable with a weight at each end and one bolted clamp,
attachable to a conductor for the purpose of damping aeolian vibration
4 General requirements
4.1 Design
The damper shall be designed so as to
– damp aeolian vibration;
– withstand mechanical loads imposed during installation, maintenance and specified service
conditions;
– avoid damage to the conductor under specified service conditions;
– be capable of being removed and re-installed without damage to the conductor;
– be free from unacceptable levels of corona and radio interference under all service
conditions;
– be suitable for safe and easy installation. The clamp design shall retain all parts when
opened for attachment to conductor. Furthermore, the clamp design shall be such that the
damper, during installation, can be suspended on the conductor before tightening the
clamp;
– ensure that individual components will not become loose in service;
– maintain its function over the entire service temperature range;
– avoid audible noise;
– prevent water collection.
NOTE – Other desirable characteristics which are not essential to the basic functions of the damper but which may
be advantageous include:
– verification of proper installation from the ground;
– ease of installation and removal from energized lines.
In the case of vibration dampers for conductors or earth wires containing integral fibre optic elements (or an
externally applied optical cable wrapped around the earth wire) account should be made of the possible effects of
the damper on these fibre optic elements.
4.2 Materials
The materials shall conform to the requirements of IEC 61284.
4.3 Mass, dimensions and tolerances
Damper mass and significant dimensions, including appropriate tolerances, shall be shown on
contract drawings.

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61897 © IEC:1998 – 13 –
4.4 Protection against corrosion
In addition to the applicable requirements of IEC 61284, the messenger cable (including cut
ends if applicable) shall be protected against corrosion, e.g. in accordance with IEC 60888 for
hot dip galvanized steel wire.
4.5 Manufacturing appearance and finish
The dampers shall be free of defects and irregularities; they shall have all outside surfaces
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.
4.7 Installation instructions
The supplier shall provide a clear and complete description of the recommended installation
procedure including in-span positions.
5 Quality assurance
A quality assurance programme taking into account the requirements of this standard can be
used by agreement between the purchaser and the supplier to verify the quality of the vibration
dampers during the manufacturing process.
Detailed information on the use of quality assurance is given in ISO 9000-1 [1], ISO 9001 [2],
*
ISO 9002 [3], ISO 9003 [4] and ISO 9004-1 [5] .
It is recommended that test equipment used to verify compliance to this standard 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 damper components is changed. The
results of type tests are recorded as evidence of compliance with design requirements.
6.1.2 Application
Dampers shall be subjected to type tests as per table 1.
Unless otherwise specified, each type test shall be performed on three test samples which are
identical in all essential respects with dampers to be supplied under contract to the purchaser.
All units shall pass the tests.
––––––––––
*
Figures in square brackets refer to the bibliography.

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61897 © IEC:1998 – 15 –
The dampers used for tests during which no damage occurs to the units or their components
may be used in subsequent tests.
6.2 Sample tests
6.2.1 General
Sample tests are required to verify that the dampers meet the performance specifications of
the type test samples. In addition, they are intended to verify the quality of material and
workmanship.
6.2.2 Application
Dampers 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 dampers used for tests during which no damage occurs to the units or their components
may be used in subsequent tests.
6.2.3 Sampling, 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 the purchaser
and the 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 appropriate to measure on some continuous scale the characteristic(s) under consideration. In
the case of failure load tests and similar expensive tests, better distinction 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 purchaser 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 he is concerned with gradual trends or changes which
may affect his 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 vibration dampers to specific requirements
and are made on every damper. The tests shall not damage the dampers.
6.3.2 Application and acceptance criteria
Whole lots of dampers may be subjected to routine tests. Any damper which does not conform
to the requirements shall be discarded.

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61897 © IEC:1998 – 17 –
6.4 Table of tests to be applied
The following 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 test shall be excluded from the delivery to the
customer.
Table 1 – Tests on dampers
Subclause Test Type Sample Routine
test test test
7.1 Visual examination X X O
7.2 Verification of dimensions, materials and mass X X
7.3 Corrosion protection tests X X
7.4 Non-destructive tests O O O
7.5 Clamp slip test X O
1)
7.6 Breakaway bolt test XX
7.7 Clamp bolt tightening test X X
7.8 Attachment of weights to messenger cable X X
7.9 Attachment of clamp to messenger cable test X X
1)
7.10 Corona and radio interference voltage (RIV) tests X
7.11 Damper performance tests
7.11.2 – Damper characteristic test X O
7.11.3 – Damper effectiveness evaluation X
7.12 Damper fatigue test X
1)
Not applicable for earth wire dampers.
NOTE – The supplier should state in the tender quality plan, or other tender documentation, which testing is
already complete (i.e. which type tests) 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 dampers 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 damper with the
contract drawings. Particular attention shall be given to markings required and to the finish of
surfaces which come into contact with the conductor. The sample test procedure and
acceptance criteria shall be agreed between the purchaser and the supplier.

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61897 © IEC:1998 – 19 –
For dampers subjected to corona type test, the sample test shall include a comparison of
shape and surface finish with one of the corona type test samples when specified by the
purchaser.
7.2 Verification of dimensions, materials and mass
Type and sample tests shall include verification of dimensions to ensure that dampers 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 and sample 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 damper complete with all its components shall comply with the mass
shown on the contract drawing (within given tolerances).
7.3 Corrosion protection tests
7.3.1 Hot dip galvanized components (other than messenger cable wires)
Hot dip galvanized components other than messenger cable wires shall be tested in
accordance with the requirements specified in ISO 1461.
The coating thicknesses shall conform to tables 2 and 3 unless otherwise agreed between
purchaser and supplier. However, for the purpose of this standard, tables 2 and 3 in ISO 1461
shall apply to the following categories of items (and not to the categories specified in
ISO 1461).
Table 2: Coating thickness on all samples except
– washers;
– threaded components;
2
– small parts which are centrifuged (significant surface area <1 000 mm ).
Table 3: Coating thickness on
– washers;
– threaded components;
2
– 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 requirements of relevant IEC/ISO standards agreed between
purchaser and supplier.
7.3.3 Hot dip galvanized messenger cable wires
Hot dip galvanized messenger cable wires shall be tested in accordance with the requirements
specified in IEC 60888.

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61897 © IEC:1998 – 21 –
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 Clamp slip test
The test shall be performed using the conductor for which the clamp is intended. The
conductor shall be "as new", i.e. free of any deterioration or damage. The minimum free length
of test conductor between its terminating fittings shall be 2 m. The conductor shall be
tensioned to 20 % of its rated tensile strength. Precautions shall be taken to avoid birdcaging
of the conductor.
The clamp shall be installed in accordance with the supplier's instructions on a different portion
of conductor for each test. In the case of breakaway bolts, the installation torque shall be the
design value minus the tolerance agreed between the purchaser and the supplier (see 7.7).
NOTE – The use of other conductors, or conductor lengths or tensions may be agreed between purchaser and
supplier.
By means of a suitable device 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 2,5 kN
(specified minimum slip load). This load shall be kept constant for 60 s. Then the load value
shall be gradually increased until slippage of the clamp occurs. The value of slip load shall be
recorded.
Clamp slip shall be considered as having occurred when a slip distance of 1 mm is measured.
• Acceptance criteria
No movement of the clamp relative to the conductor greater than 1 mm shall occur at or before
the end of application of 2,5 kN for 60 s. If both a minimum and a maximum slip load are
stated, the slip shall occur between those values. Surface flattening of the outer strands of the
conductor is acceptable.
7.6 Breakaway bolt test
The breakaway bolts, if used, shall be tested by applying increasing torque to the breakaway
portion until it breaks away. The breakaway torque shall be recorded. The breakaway torque
shall be within the tolerance agreed between the purchaser and the supplier.

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61897 © IEC:1998 – 23 –
7.7 Clamp bolt tightening test
The test shall be performed by installing the clamp on a length of the conductor for which the
damper is intended. If the damper is to be used for two or more sizes or types of conductor,
then the clamp shall be tested on each conductor unless the purchaser agrees to test on one
conductor only.
The bolts or nuts shall be tightened to a torque 10 % above the specified installation torque.
Clamps with breakaway bolts shall have the breakaway portion of the head removed prior to
the test and shall be tightened with the specified torque value plus the agreed tolerance. The
threaded connection shall remain serviceable for any number of subsequent installations or
removals and all components of the clamp shall be undamaged. No unacceptable damage shall
occur to the conductor inside the clamp. Unacceptable damage shall be agreed between the
purchaser and the supplier.
Lastly, the torque shall be increased to either twice the specified installation value or the
maximum torque value recommended by the bolt supplier whichever is lower.
This increase shall not result in any breakage of threaded parts or other components.
7.8 Attachment of weights to messenger cable
On an assembled damper a tensile load shall be applied between the weights coaxial with the
messenger cable. The load shall be gradually increased (100 N/s maximum) until it reaches
5 kN (specified minimum slip load). This load shall be kept constant for 60 s.
The load shall then be increased slowly until one weight has been pulled free of the messenger
cable. The maximum load obtained during this process shall be recorded, for information
purposes only.
• Acceptance criteria
No relative movement greater than 1 mm between each weight and the messenger cable shall
occur at or before the end of the application of 5 kN for 60 s.
NOTE – It may be necessary to remove the load before measuring the distance between the weights, i.e. when the
elastic stretch of the messenger cable results in an apparent movement of the weights along the messenger cable.
7.9 Attachment of clamp to messenger cable test
A tensile load shall be applied between the messenger cable and the clamp body, coaxial with
the messenger cable. The load shall be gradually increased (100 N/s maximum) until it reaches
1,5 kN (specified minimum slip load). This load shall be kept constant for 60 s.
The load shall then be increased slowly until the clamp has been pulled free of the messenger
cable. The maximum load obtained during this process shall be recorded, for information
purposes only.
• Acceptance criteria
No movement of the clamp relative to the messenger cable grea
...