EN 61854:1998

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Freileitungen - Anforderungen und Prüfungen für FeldabstandhalterLignes aériennes - Exigences et essais applicables aux entretoisesOverhead lines - Requirements and tests for spacers29.240.20DaljnovodiPower transmission and distribution linesICS:Ta slovenski standard je istoveten z:EN 61854:1998SIST EN 61854:1999en,fr01-november-1999SIST EN 61854:1999SLOVENSKI
STANDARD
NORMEINTERNATIONALECEIIECINTERNATIONALSTANDARD61854Première éditionFirst edition1998-09Lignes aériennes –Exigences et essais applicables aux entretoisesOverhead lines –Requirements and tests for spacers Commission Electrotechnique Internationale International Electrotechnical
CommissionPour prix, voir catalogue en vigueurFor price, see current
catalogueÓ IEC 1998
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61854 © IEC:1998– 3 –CONTENTSPageFOREWORD.7Clause1Scope.92Normative references.93Definitions.134General requirements.134.1Design.134.2Materials.154.2.1General.154.2.2Non-metallic materials.154.3Mass, dimensions and tolerances.154.4Protection against corrosion.154.5Manufacturing appearance and finish.154.6Marking.154.7Installation instructions.155Quality assurance.176Classification of tests.176.1Type tests.176.1.1General.176.1.2Application.176.2Sample tests.176.2.1General.176.2.2Application.176.2.3Sampling and acceptance criteria.196.3Routine tests.196.3.1General.196.3.2Application and acceptance criteria.196.4Table of tests to be applied.197Test methods.237.1Visual examination.237.2Verification of dimensions, materials and mass.237.3Corrosion protection test.237.3.1Hot dip galvanized components (other than stranded galvanizedsteel wires).237.3.2Ferrous components protected from corrosion by methods other thanhot dip galvanizing.257.3.3Stranded galvanized steel wires.257.3.4Corrosion caused by non-metallic components.257.4Non-destructive tests.25

61854 © IEC:1998– 5 –ClausePage7.5Mechanical tests.277.5.1Clamp slip tests.277.5.1.1Longitudinal slip test.277.5.1.2Torsional slip test.297.5.2Breakaway bolt test.297.5.3Clamp bolt tightening test.317.5.4Simulated short-circuit current test and compression and tension tests.317.5.4.1Simulated short-circuit current test.317.5.4.2Compression and tension test.337.5.5Characterisation of the elastic and damping properties.337.5.6Flexibility tests.397.5.7Fatigue tests.397.5.7.1General.397.5.7.2Subspan oscillation.417.5.7.3Aeolian vibration.417.6Tests to characterise elastomers.437.6.1General.437.6.2Tests.437.6.3Ozone resistance test.477.7Electrical tests.477.7.1Corona and radio interference voltage (RIV) tests.477.7.2Electrical resistance test.477.8Verification of vibration behaviour of the bundle-spacer system.49Annex A (normative)
Minimum technical details to be agreed betweenpurchaser and supplier.65Annex B (informative)
Compressive forces in the simulated short-circuit current test.67Annex C (informative)
Characterisation of the elastic and damping propertiesStiffness-Damping Method.71Annex D (informative)
Verification of vibration behaviour of the bundle/spacer system.75Bibliography.81Figures.51Table 1 – Tests on spacers .21Table 2 – Tests on elastomers .
61854 © IEC:1998– 7 –INTERNATIONAL ELECTROTECHNICAL COMMISSION––––––––––OVERHEAD LINES –REQUIREMENTS AND TESTS FOR SPACERSFOREWORD1)The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committees). The object of the IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. Tothis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committee interested in the subject dealt with mayparticipate in this preparatory work. International, governmental and non-governmental organizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the International Organizationfor Standardization (ISO) in accordance with conditions determined by agreement between the twoorganizations.2)The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, aninternational consensus of opinion on the relevant subjects since each technical committee has representationfrom all interested National Committees.3)The documents produced have the form of recommendations for international use and are published in the formof 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 InternationalStandards transparently to the maximum extent possible in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.5)The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for anyequipment 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 subjectof patent rights. The 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: Overheadlines.The text of this standard is based on the following documents:FDISReport on voting11/141/FDIS11/143/RVDFull information on the voting for the approval of this standard can be found in the report onvoting indicated in the above table.Annex A forms an integral part of this standard.Annexes B, C and D are for information only.

61854 © IEC:1998– 9 –OVERHEAD LINES –REQUIREMENTS AND TESTS FOR SPACERS1 ScopeThis International Standard applies to spacers for conductor bundles of overhead lines. Itcovers rigid spacers, flexible spacers and spacer dampers.It does not apply to interphase spacers, hoop spacers and bonding spacers.NOTE – This standard is written to cover the line design practices and spacers most commonly used at the time ofwriting. There may be other spacers available for which the specific tests reported in this standard may not beapplicable.In many cases, test procedures and test values are left to agreement between purchaser andsupplier and are stated in the procurement contract. The purchaser is best able to evaluate theintended 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 arelisted.2 Normative referencesThe following normative documents contain provisions which, through reference in this text,constitute provisions of this International Standard. At the time of publication of this standard,the editions indicated were valid. All normative documents are subject to revision, and partiesto agreements based on this International Standard are encouraged to investigate thepossibility 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: OverheadlinesIEC 61284:1997, Overhead lines – Requirements and tests for fittingsIEC 60888:1987, Zinc-coated steel wires for stranded conductorsISO 34-1:1994, Rubber, vulcanized or thermoplastic – Determination of tear strength – Part 1:Trouser, angle and crescent test piecesISO 34-2:1996, Rubber, vulcanized or thermoplastic – Determination of tear strength – Part 2:Small (Delft) test piecesISO 37:1994, Rubber, vulcanized or thermoplastic – Determination of tensile stress-strainproperties

61854 © IEC:1998– 11 –ISO 188:1982, Rubber, vulcanized – Accelerated ageing or heat-resistance testsISO 812:1991, Rubber, vulcanized – Determination of low temperature brittlenessISO 815:1991, Rubber, vulcanized or thermoplastic – Determination of compression set atambient, elevated or low temperaturesISO 868:1985, Plastics and ebonite – Determination of indentation hardness by means of adurometer (Shore hardness)ISO 1183:1987, Plastics – Methods for determining the density and relative density of non-cellular plasticsISO 1431-1:1989, Rubber, vulcanized or thermoplastic – Resistance to ozone cracking –Part 1: static strain testISO 1461, — Hot dip galvanized coatings on fabricated ferrous products – Specifications 1)ISO 1817:1985, Rubber, vulcanized – Determination of the effect of liquidsISO 2781:1988, Rubber, vulcanized – Determination of densityISO 2859-1:1989, Sampling procedures for inspection by attributes – Part 1: Sampling plansindexed by acceptable quality level (AQL) for lot-by-lot inspectionISO 2859-2:1985, Sampling procedures for inspection by attributes – Part 2: Sampling plansindexed by limiting quality level (LQ) for isolated lot inspectionISO 2921:1982, Rubber, vulcanized – Determination of low temperature characteristics –Temperature-retraction procedure (TR test)ISO 3417:1991, Rubber – Measurement of vulcanization characteristics with the oscillating disccuremeterISO 3951:1989, Sampling procedures and charts for inspection by variables for percentnonconformingISO 4649:1985, Rubber – Determination of abrasion resistance using a rotating cylindricaldrum deviceISO 4662:1986, Rubber – Determination of rebound resilience of vulcanizates–––––––––1) To be published.

61854 © IEC:1998– 13 –3 DefinitionsFor the purpose of this International Standard the definitions of the InternationalElectrotechnical Vocabulary (IEV) apply, in particular IEC 60050(466). Those which differ or donot appear in the IEV are given below.3.1rigid spacerspacer allowing no relative movement between the subconductors at the spacer location3.2flexible spacerspacer allowing relative movements between the subconductors at the spacer location3.3spacer systemcomplex of spacers and the relevant in-span distribution4 General requirements4.1 DesignThe spacer shall be designed as to–maintain subconductor spacing (at spacer locations), within any prescribed limits, under allconditions of service excluding short-circuit currents;–prevent, in subspans between spacers, physical contact between subconductors, exceptduring the passage of short circuit currents when the possibility of contact is acceptedprovided that the specified spacing is restored immediately following fault clearance;–withstand mechanical loads imposed on the spacer during installation, maintenance andservice (including short circuit conditions) without any component failure or unacceptablepermanent deformation;–avoid damage to the subconductor under specified service conditions;–be free from unacceptable levels of corona and radio interference under specified serviceconditions;–be suitable for safe and easy installation. For the bolted and latching clamp the design shallretain 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 thespacer 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 maybe advantageous to the purchaser, include:–verification of proper installation from the ground,–ease of installation and removal from energized lines.

61854 © IEC:1998– 15 –4.2 Materials4.2.1 GeneralSpacers shall be made of any materials suitable for their purpose. Unless additionalrequirements are stated, the material shall conform to the requirements of IEC 61284.4.2.2 Non-metallic materialsIn addition to the requirements of IEC 61284, the conductivity of the various non-metalliccomponents 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.4.3 Mass, dimensions and tolerancesSpacer mass and significant dimensions, including appropriate tolerances, shall be shown oncontract drawings.NOTE – Tolerances applied to the mass and to the dimensions should ensure that the spacers meet their specifiedmechanical and electrical requirements.4.4 Protection against corrosionIn addition to the applicable requirements of IEC 61284, stranded steel wires, if used, shall beprotected against corrosion in accordance with IEC 60888.4.5 Manufacturing appearance and finishThe spacers shall be free of defects and irregularities; all outside surfaces shall be smooth andall edges and corners well-rounded.4.6 MarkingThe fitting marking requirements of IEC 61284 shall be applied to all clamp assembliesincluding 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 instructionsThe supplier shall provide a clear and complete description of the installation procedure and, ifrequired, the in-span location of the spacers.The supplier shall make available any special installation tool that is required.

61854 © IEC:1998– 17 –5 Quality assuranceA quality assurance programme taking into account the requirements of this standard can beused by agreement between the purchaser and the supplier to verify the quality of the spacersduring the manufacturing process.Detailed information on the use of quality assurance is given in the following ISO standardsISO 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 routinelymaintained and calibrated in accordance with a relevant quality standard.6 Classification of tests6.1 Type tests6.1.1 GeneralType tests are intended to establish design characteristics. They are normally made once andrepeated only when the design or the material of the spacer is changed. The results of typetests are recorded as evidence of compliance with design requirements.6.1.2 ApplicationSpacers shall be subjected to type tests as per table 1. Each type test shall be performed onthree samples which are identical, in all essential respects, with the spacers to be suppliedunder 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 componentsmay be used in subsequent tests.NOTE – The unit subjected to type tests can be either a complete spacer or a component of the spacer asappropriate to the test.6.2 Sample tests6.2.1 GeneralSample tests are required to verify that the spacers meet the performance specifications of thetype test samples. In addition, they are intended to verify the quality of materials andworkmanship.6.2.2 ApplicationSpacers 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. Thepurchaser has the right to make the selection.–––––––––* Figures in square brackets refer to the bibliography.

61854 © IEC:1998– 19 –The spacers used for tests during which no damage occurs to the units or their componentsmay be used in subsequent tests.NOTE – The unit subjected to sample tests can be either a complete spacer or a component of the spacer asappropriate to the test.6.2.3 Sampling and acceptance criteriaThe sampling plan procedures according to ISO 2859-1 and ISO 2859-2 (inspection byattributes) and ISO 3951 (inspection by variables) and the detailed procedures (inspectionlevel, AQL, single, double or multiple sampling, etc.) shall be agreed between purchaser andsupplier for each different attribute or variable.NOTE – Sampling inspection by variables is an acceptance sampling procedure to be used in place of inspection byattributes when it is more appropriate to measure on some continuous scale the characteristic(s) underconsideration. In the case of failure load tests and similar expensive tests, better discrimination between acceptablequality and objective quality is available with acceptance sampling by variables than by attributes for the samesample 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 ashipment lot are within a required dimensional tolerance; the manufacturer may make measurements under avariables sampling plan of the same dimensions because of concern with gradual trends or changes which mayaffect the ability to provide shipment lots which meet the AQL.6.3 Routine tests6.3.1 GeneralRoutine tests are intended to prove conformance of spacers to specific requirements and aremade on every spacer. The tests shall not damage the spacers.6.3.2 Application and acceptance criteriaWhole lots of spacers may be subjected to routine tests. Any spacer which does not conform tothe requirements shall be discarded.6.4 Table of tests to be appliedTable 1 indicates the tests which shall be performed. These are marked with an "X" in thetable.However, the purchaser may specify additional tests which are included in the table andmarked with an "O".Units or components damaged during the tests shall be excluded from the delivery to thecustomer.

Table 1 – Tests on spacersSpacer damperFlexible spacerRigid spacerClauseTestTypetestSampletestRoutinetestTypetestSampletestRoutinetestTypetestSampletestRoutinetest7.1Visual examinationXXOXXOXXO7.2Verification of dimensions,material and massXXOXXOXXO7.3Corrosion protection testsX 1)X 1)X 1)X 1)X 1)X 1)7.4Non-destructive testsOOOOOOOOO7.5Mechanical tests7.5.1–clamp slip testsXOXOXO7.5.2–breakaway bolt testXXXXXX7.5.3–clamp bolt tightening testXXXXXX7.5.4–simulated short-circuit current testand compression and tension testsXOXOXO7.5.5–characterisation of the elasticand damping propertiesXOOO7.5.6–flexibility testsXOXO7.5.7–fatigue testsXO7.6Tests to characterise elastomersXOX 1)O 1)7.7Electrical tests7.7.1–corona and radio interference voltage(RIV) testsXXX7.7.2–electrical resistance testXOX 1)O 1)O 1)7.8Verification of vibration behaviourof the bundle/spacer systemD.2–aeolian vibrationOO 2)D.3–subspan oscillationOO1) 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 orroutine) are included in the tender, subject to the approval or change required by the purchaser.

61854 © IEC:1998– 23 –7 Test methods7.1 Visual examinationType tests shall include visual examination to ascertain conformity of the spacers, in allessential respects, with the manufacturing or contract drawings. Deviations from the drawingsshall be subject to the approval of the purchaser and shall be appropriately documented as anagreed concession.Sample tests and, if required, routine tests shall include visual examination to ensureconformity of manufacturing process, shape, coating and surface finish of the spacer with thecontract drawings. Particular attention shall be given to the markings required and to the finishof surfaces which come into contact with the conductor.The sample test procedures and acceptance criteria shall be agreed between purchaser andsupplier.For spacers subject to corona type tests, the sample test shall include a comparison of shapeand surface finish with one of the corona type test samples when specified or agreed by thepurchaser.7.2 Verification of dimensions, materials and massType, sample and, if required, routine tests shall include verification of dimensions to ensurethat spacers are within the dimensional tolerances stated on contract drawings. The purchasermay choose to witness the measurement of selected dimensions or may inspect the supplier'sdocumentation when this is available.Type, sample and, if required, routine tests shall also include verification of materials to ensurethat they are in accordance with contract drawings and documents. This verification shallnormally be carried out by the purchaser inspecting the supplier's documentation relating tomaterial specifications, certificates of conformity or other quality documentation.The total mass of the spacer complete with all its components shall comply with the massshown on the contract drawing (within given tolerances).7.3 Corrosion protection test7.3.1 Hot dip galvanized components (other than stranded galvanized steel wires)Hot dip galvanized components other than stranded galvanized steel wires shall be tested inaccordance with the requirements specified in ISO 1461.The coating thicknesses shall conform to tables 2 and 3 unless otherwise agreed betweenpurchaser and supplier. However, for the purpose of this standard, tables 2 and 3 of ISO 1461shall apply to the following categories of items (and not to the categories specified inISO 1461).

61854 © IEC:1998– 25 –Table 2:coating thickness on all samples except–washers;–threaded components;–small parts which are centrifuged (significant surface area < 1 000 mm2).Table 3:coating thickness on–washers;–threaded components;–small parts which are centrifuged (significant surface area < 1 000 mm2).7.3.2 Ferrous components protected from corrosion by methods otherthan hot dip galvanizingFerrous components protected from corrosion by methods other than hot dip galvanizing shallbe tested in accordance with the requirement of the relevant IEC/ISO standards, agreedbetween purchaser and supplier.7.3.3 Stranded galvanized steel wiresStranded galvanized steel wires shall be tested in accordance with the requirements specifiedin IEC 60888.7.3.4 Corrosion caused by non-metallic componentsBy agreement between purchaser and supplier, evidence of non-corrosion compatibilitybetween the elastomer and the conductor or spacer components, as appropriate, shall bedemonstrated by a corrosion test or by suitable service experience. Alternatively, and whereappropriate, the purchaser may specify for each subassembly containing an elastomer, a rangeof electrical resistance which provides adequate conductivity for electrical charging butminimizes galvanic action.NOTE – Non-metallic components, especially elastomeric elements lining a spacer clamp or providing the flexibilityand damping in a spacer damper, are commonly made electrically conducting to avoid any problems that mightotherwise arise from the capacitive charging of the arms or body of the spacer. Carbon is frequently used inelastomer 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 pollutedenvironment. Other constituents of non-metallic components, such as chlorides, free sulphur, etc. may also havecorrosive effects.7.4 Non-destructive testsThe purchaser shall specify or agree to relevant test methods (ISO or other) and acceptancecriteria. 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.

61854 © IEC:1998– 27 –7.5 Mechanical tests7.5.1 Clamp slip testsThe tests shall be performed using the conductor for which the clamps are intended. Theconductor shall be "as new", i.e. free of any deterioration or damage. The minimum length ofthe test conductor between its terminating fittings shall be, with the exception of the test inclause 7.5.1.2 B), 4 m. The conductor shall be tensioned to 20 % of its rated tensile strength.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 thesupplier's instructions. In the case of breakaway bolts, the installation torque shall be thedesign value minus the tolerance agreed between purchaser and supplier (see 7.5.3).NOTE – The use of other conductor, conductor lengths and tensions can be agreed between purchaser andsupplier.7.5.1.1 Longitudinal slip testA)By means of a suitable device (see figure 1a), a load coaxial to the conductor shall beapplied to the clamp.The load shall be gradually increased (not faster than 100 N/s) until it reaches the specifiedminimum slip load value. This load shall be kept constant for 60 s. Then the load shallbe gradually increased until slippage of the clamp occurs. The slip load value shall berecorded.For metal surface clamps, slip shall be considered as having occurred when a movement ofthe 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 criteriaNo slippage shall occur at or below the minimum specified value. If both minimum andmaximum slip requirements are stated, the slip shall occur between those values. Surfaceflattening of the outer strands of the conductor is acceptable.B)An alternative test arrangement which evaluates the performance of the whole spacerassembly under simulated broken conductor conditions, as well as clamp slip, is shown infigure 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 bemounted on the subconductors and a longitudinal force shall be applied to the untensionedsubconductor.The load shall be gradually increased (not faster than 100 N/s) until it reaches the specifiedminimum slip load value. This load shall be kept constant for 60 s. Then the load shall begradually increased until slippage of the clamp occurs. The slip load value shall berecorded.

61854 © IEC:1998– 29 –For metal surface clamps, slip shall be considered as having occurred when a movement ofthe 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 criteriaThe slip force of the clamp on the subconductor or the failure load of the spacer shall notbe less than the minimum specified value. In addition, if required by the purchaser, thelongitudinal movement of the initially untensioned subconductor with respect to its initialposition shall be higher than the minimum specified value at the moment of the slippage.7.5.1.2 Torsional slip testA)A torque (see figure 2a) shall be applied to the clamps in order to rotate it around the axisof the conductor.The torque shall be gradually increased until it reaches the specified minimum slip torque.This torque shall be kept constant for 60 s. Then the torque shall be gradually increaseduntil slippage of the clamp by torsion occurs. The slip torque value shall be recorded.The test shall be carried out applying the torque in the direction of lay of the outerconductor strands. The test shall be repeated by applying the torque in the oppositedirection.Clamp slip shall be considered as having occurred when a slip value greater than onestrand diameter is measured after the release of load.· Acceptance criteriaNo slippage shall occur at or below the minimum specified value.B)An alternative test arrangement is shown in figure 2b.A conductor of length L equal to the average sub-span associated with the tested spacer,shall be tensioned to 20 % of its rated tensile strength. The spacer shall be mounted at thecentre of the test conductor (l1 = l2 = L/2). Then the tension on the test conductor shall beincreased to 40 % of its rated tensile strength. The spacer shall be rotated to an angle gl,specified or agreed by the purchaser, around the axis of the conductor.The test shall be carried out applying the torque in the direction of lay of the outerconductor strands. The test shall be repeated by applying the torque in the oppositedirection.NOTE – The test may be performed with unequal lengths l1 and l2. In this case, the recommended angle ofrotation isgg=´+æèçöø÷41212lLllll (degrees)Clamp slip shall be considered as having occurred when a slip value greater than onestrand diameter is measured after release of load.· Acceptance criteriaNo slippage shall occur at or below gl.7.5.2 Breakaway bolt testThe breakaway bolt, if used, shall be tested by applying increasing torque to the breakawayportion of the bolt until it breaks away. The breakaway torque shall be recorded. The break-away torque shall be within the tolerance agreed between purchaser and supplier.

61854 © IEC:1998– 31 –7.5.3 Clamp bolt tightening testThe test shall be performed by installing the clamp on a conductor with a diameter equal to thatfor which the clamp is intended to be used. The bolt(s) or nut(s) shall be tightened to a torque10 % above the specified installation torque. Clamps with breakaway bolts shall have thebreakaway portion of the head removed prior to the test and shall be tightened with thespecified torque value plus the agreed tolerance. The threaded connection shall remainserviceable for any number of subsequent installations and removals and all components of theclamp shall be undamaged. No unacceptable damage shall occur on the conductor inside theclamp. Unacceptable damage shall be agreed between purchaser and supplier.Lastly, the torque shall be increased either to twice the specified installation torque or themaximum torque value recommended by the bolt supplier, whichever is lower. This increaseshall not result in any breakage of threaded parts or other components.7.5.4 Simulated short-circuit current test and compression and tension testsThe purpose of these tests is to ensure that the spacers will be able to withstand, withoutfailure or permanent deformation, the compressive and tensile load which may occur in service.The purchaser shall specify or agree to one of the following tests, or any combination of tests.NOTE – The effects imposed by the loads in the different tests, or combination of tests, are not necessarilyequivalent.7.5.4.1 Simulated short-circuit current testSuitable devices (see figure 3) which are able to apply compressive forces (directed towardthe centre of the conductor bundle) and tensile forces (directed away from the centre of theconductor bundle) to all spacer clamps simultaneously shall be used.· CompressionThe compressive forces shall be gradually increased until they reach the specified value. Atthis value the forces shall be held constant for 60 s and then removed. The test shall beexecuted twice; the first one with the spacer in its normal position and the second one with oneclamp displaced longitudinally of an agreed amount, with reference to the other clamp(s).The value of the compressive force specified above can be calculated using the formula givenin annex B unless a different value is agreed between purchaser and supplier.· TensionFollowing compressive forces, tensile forces shall be applied. These forces shall be graduallyincreased until they reach the specified value at which they shall be maintained for 60 s. Thevalue of the tensile forces shall be taken as 50 % of the corresponding compressive forces,unless a different value is agreed between purchaser and supplier.

61854 © IEC:1998– 33 –· Acceptance criteriaAfter the test,–it shall be possible to return the spacer clamps to their design position using only slighthand pressure;–the spacer shall be examined by disassembly if necessary. There shall be no deformationor damage which would impair the efficiency of the spacer or affect its function ofmaintaining the normal bundle spacing.7.5.4.2 Compression and tension testThe spacer assembly shall be installed on a suitable device (see figure 4) able to applycompression and tension forces between each pair of adjacent clamps.The clamp bolts, when used, shall be tightened to the specified installation torque.For each pair of adjacent clamps, the compressive force shall first be applied. The force shallbe gradually increased until it reaches the specified value which shall be maintained for 60 s.Then the compressive force shall be removed and the tensile force shall be applied to thesame pair of clamps and held for 60 s at the specified value.The value of the compressive and tensile forces to be applied shall be agreed betweenpurchaser and supplier.· Acceptance criteriaAfter the test,–it shall be possible to return the spacer clamps to their design position using only slighthand pressure;–the spacer shall be examined by disassembly if necessary. There shall be no deformationor damage which would impair the efficiency of the spacer or affect its function ofmaintaining the normal bundle spacing.7.5.5 Characterisation of the elastic and damping propertiesTests to determine the elastic and damping properties of spacer dampers shall be performed inaccordance with one or more of the following methods as specified or agreed by the purchaser.NOTE 1 – The stiffness and damping values do not provide direct confirmation of the performance of spacerdampers installed on conductor bundles, but they may be used in analytical models used to provide indication ofperformance, particularly with regard to aeolian vibration.NOTE 2 – The stiffness and damping values determined in type tests can be used to establish acceptance criteriafor sample tests as specified or agreed by the purchaser.NOTE 3 – The elastic and damping characteristics determined in the following different tests are not equivalent.

61854 © IEC:1998– 35 –A)Stiffness-damping methodThe frame of the spacer shall be fixed securely and a rigid tube or rod shall be securelyheld in one of the spacer clamps. The tube/rod shall be oscillated (see annex C) such thatthe angle of deflection of the spacer arm from its unloaded position follows a sinusoid, i.e.j = F sin wtwherejis the angle of deflectionFis the peak value of deflection selected for the measurement.The peak force F required to oscillate the spacer arm through the angle measurement ±Fshall be determined (measured at approximately 90° to the arm axis in the plane of thespacer and passing through the centre of the clamp).The phase angle, a, between the force and arm deflection angle shall also be determined.If necessary the arm oscillation shall be maintained for a period long enough to stabilize thetemperature of the damping element(s) before measuring F and a.The angle a may be measured directly by comparing the force and arm angle wave forms.It may also be determined indirectly by measuring the area of the hysteresis loop formed bydisplaying the force and arm angle deflection in X-Y form. In this case a can be calculatedas follows:a = arcsin [E/(F l p F)]whereais the phase angle between arm deflection and force (rad);Eis the area of the moment/angular deflection loop (J);Fis the peak force (N);lis the arm length measured between clamp centre and effective frame/arm pivot point (m);Fis the peak arm deflection (rad).The test shall be carried out at a frequency between 1 Hz and 2 Hz with a peak-to-peakdisplacement equivalent to the diameter of the conductor for which the clamp is intended tobe used.NOTE – Tests at a variety of frequencies and/or displacements can be used to characterize spacer dampers forcomputer programs.From the measurements of F and a, the torsional stiffness Kt and the damping constant Htshall be calculated as follows:Kt = (F ´ l ´ cos a) / F(Nm/rad)Ht = Kt ´ tan a(Nm/rad)· Acceptance criteria–The torsional stiffness Kt shall not differ by more than ±20 % from the value declared bythe supplier and stated on contract drawings.–The ratio Ht/Kt shall not be lower than 20 % of the value declared by the supplier andstated on contract drawings.

61854 © IEC:1998– 37 –B)Stiffness methodAfter being held at a test reference temperature of (20 ± 5) °C for at least 3 h, thehorizontal stiffness of a spacer shall be determined in the following manner:–the spacer shall be held (preferably in its working orientation) by two adjacent clampsinstalled on horizontal rods which are free to rotate;–one rod shall be held in position and a force shall be applied to the other rod justsufficient to move the clamp arms to their stops in tension, i.e. the spacing shall havebeen increased from Xnom to Xmax which shall be recorded;–the above shall be repeated for the arms in compression for Xmin to be recorded;–spacings Xt and Xc shall then be determined, whereXt = Xnom + 0,9 (Xmax – Xnom)Xc = Xnom – 0,9 (Xnom – Xmin)–The spacer arms shall then be moved in the following cycle:· starting at Xnom the spacing shall be increased to Xt at a uniform rate between50 mm/min and 100 mm/min;· the spacing shall be held at Xt and after 60 s the force Ft required to hold thisspacing shall be recorded;· the spacing shall then be decreased at a uniform rate between 20 mm/min and50 mm/min until the spacing is again equal to Xnom;· after holding the spacing at Xnom between 0 s and 20 s, the spacing shall bedecreased to Xc at a uniform rate between 50 mm/min and 100 mm/min;· the spacing shall be held at Xc and after 60 s the force Fc required to hold thisspacing shall be recorded;· the stiffness shall then be determined as (Ft + Fc)/(Xt – Xc).NOTE – To illustrate the above, assume that the test is carried out on a 400 mm twin spacer which has stops atspacings of 420 mm and 370 mm. It will then be necessary to record the tensile force Ft (N) required tomaintain a spacing of 418 mm and the compression force Fc (N) required to maintain a spacing of 373 mm. Thestiffness will then be (Ft + Fc)/45 (N/mm).· Acceptance criteriaThe stiffness shall not differ by more than ±20 % from the value declared by the supplierand stated on contract drawings.C)Damping methodThe damping characteristic shall be determined as follows.The body of the spacer shall be fixed rigidly, and a mass shall be added to one arm suchthat the natural frequency of oscillation is between 1 Hz and 2 Hz. The arm shall then bemoved to one of the end stops and, after 1 min, suddenly released. The movement of thearm shall be recorded for at least two complete cycles. If the initial swing (from startingposition to maximum deflection in the opposite direction) is Y1 and subsequent swings(peak to peak) are Y2, Y3, Y4 the log decrement shall be taken to be equal toln 121324YYYY+æèçöø÷éëêêùûúúNOTE – This definition is different to the conventional one (ln[Ao/An]/n) but is less sensitive to measurementerror and does not require the zero deflection position to be determined.· Acceptance criteriaThe log decrement shall not differ by more than ±20 % from the v
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