1、Designation: F2973 14Standard Specification forInsulating Lifting Links for Load Lifting Equipment WorkingNear Energized Power Lines1This standard is issued under the fixed designation F2973; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers insulating lifting links used forprotection of workers positioning a lo
3、ad from accidentalcontact of the load lifting equipment with live electricalconductors, apparatus, and circuits.1.2 This specification includes design, material, and testingrequirements for the manufacturer and in-service inspection,testing and care requirements for the user or the agent of theuser.
4、1.3 Insulating links whose primary application does notpertain to power line electrical safety are not within the scopeof this specification.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard does not purport
5、to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E4 Prac
6、tices for Force Verification of Testing MachinesF819 Terminology Relating to Electrical Protective Equip-ment for Workers2.2 IEEE Standard:3IEEE 4 Standard Techniques for High-Voltage Testing2.3 ISO Standard:4ISO 75001 Metallic materials - Verification of static uni-axial testing machines - Part 1:
7、Tensile testing machines -Corrigendum3. Terminology3.1 DefinitionsTerminology used in this specification is inaccordance with Terminology F819.3.2 Definitions of Terms Specific to This Standard:3.2.1 design verification test, ntest made on a sampletreated as representative of an industrial product.3
8、.2.2 electrical test, na test ensuring that a product meetsthe minimum electrical requirements of the standard.3.2.3 flashover, na disruptive discharge over the surface ofthe insulating link.3.2.4 mechanical test, na test confirming that a productmeets the minimum mechanical requirements of a standa
9、rd.3.2.5 proof load, nspecific mechanical load applied in theperformance of the proof load test.3.2.6 proof test, nmechanical and electrical tests per-formed by the manufacturer on all production units.3.2.7 puncture, ndisruptive discharge through an insula-tor.3.2.8 qualified personnel, npersonnel
10、who, by possessionof a recognized degree, certificate, professional standing, orskill, and who, by knowledge, training, and experience, havedemonstrated the ability to deal with problems relating to thesubject matter, the work, or the project.3.2.9 rated load, nthe maximum working load.3.2.10 visual
11、 inspection, nvisual check made to detectdefects that impede the performance of a product(s).4. Materials and Manufacture4.1 The mechanical design factor shall not be less than 5.0times its rated load for ratings up to 100 tons and 4.0 timesrated load for ratings 100 tons and up.1This specification
12、is under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and is the direct responsibility ofSubcommittee F18.55 on Inspection and Non-Destructive Test Methods for AerialDevices.Current edition approved Oct. 1, 2014. Published October 2014. DOI: 10.1520/F2973-142F
13、or referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Institute of Electrical and Electronics Enginee
14、rs, Inc. (IEEE),445 Hoes Ln., Piscataway, NJ 08854, http:/www.ieee.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. Un
15、ited States14.2 The electrical design factor of the link shall not be lessthan 2 times it rated use voltage.4.3 The insulation system shall not absorb water and shallhave a water repellent surface.4.4 Weather shields shall be made of impact resistantnonconductive material.4.5 UV resistant polymers s
16、hould be employed by themanufacturer if, without them, electrical performance may beaffected.4.6 Steel used shall meet ASTM or AISI standards.5. Workmanship and Finish5.1 The insulating surface of the links shall be free ofcracks, nicks, gouges, damage to the insulating surface thatwould affect its
17、insulating properties in both dry and wetconditions.5.2 MarkingsEach link should bear permanent,accessible, and readily visible markings that include, at aminimum, the manufacturers mark, ASTM XXX, unit serialnumber, rated voltage, and rated load.5.3 ManualsThe manufacturer shall provide a manualwit
18、h each link. The manual shall contain:5.3.1 Descriptions, specifications, and ratings of the link.5.3.2 Ambient temperature range for which the link isdesigned.5.3.3 Precautions concerning weather.5.3.4 Instructions regarding routine and frequency of in-spections and maintenance.6. General Test Requ
19、irements6.1 Personnel responsible for the tests outlined in thisdocument shall be qualified individuals as per 3.2.8, knowl-edgeable in the use of the test equipment used for tensileloading and high-voltage testing.6.2 The electrical test equipment shall meet the require-ments of IEEE 4-1995. The me
20、tering systems including mea-surement cable used to measureAC current shall have a systemerror of5%orless.6.3 The electrical test set up shall provide the operatorprotection in the performance of his duties and isolate thespecimen to guard against accidental contact by persons in thevicinity.6.4 The
21、 ambient temperature for the test location shall notbe lower than 15.5 C.6.5 Electrical discharge characteristics and measured cur-rent of a test object can be affected by its general arrangement,such as the clearance from other energized or groundedstructures, the height above ground level, or the
22、arrangement ofthe high-voltage lead that may affect flashover voltages. Forthat reason, the general arrangement should be as shown in Fig.1 for testing links that are not installed on load liftingequipment.6.6 Clearance to nearby structures that are equal to orgreater than two times the length of th
23、e shortest possibleelectrical discharge path on the test object should make anyproximity effects negligible.7. Design Verification Tests7.1 Design verification tests are to be performed on at leastone representative unit from each class of insulating link, andthis will qualify that class of link mod
24、els of variable rated loadsfor a given rated voltage. A test unit is considered to berepresentative of its group if it meets the following require-ments:7.1.1 The same structural and dielectric materials, structuraldesigns, manufacturing, and assembly methods apply to alllinks in the group,7.1.2 The
25、 same structural stress and loading analysis can beapplied to all the links in the group,7.1.3 The test unit has the same or smaller electricalcreepage and arcing distances per kV of rating.7.2 Mechanical Design Verification Test Procedure:7.2.1 The insulating link shall withstand a tensile load tes
26、tof 5.0 times its rated load for rating up to 100 tons and 4.0times rated load for ratings 100 tons and up for 60 s withoutseparation. The tensile load test is to be performed on a test bedFIG. 1 Suggested Test Set Up for Insulated LinksF2973 142or hydraulic pulling machine calibrated to the latest
27、revision ofeither ASTM E4 or ISO 75001.7.3 Electrical Design Verification Test Procedure:7.3.1 Three electrical tests to verify design voltage ratingshall be peformed.7.3.2 The insulating link will withstand an applied ACvoltage while dry of twice the link-rated AC voltage for 5 minwithout dielectri
28、c puncture or flashover and leakage of no morethan 3 mA.7.3.3 The link shall be tested to verify that it does not absorbwater with time.7.3.3.1 Install the link in a humidity chamber for 48 h at atemparature between 65 and 100 F with a minimum of 93 %relative humidity.7.3.3.2 Within a time frame of
29、5 min after removal fromhumidity chamber in the vertical use position apply DC voltagein accordance with Table 1. Increase voltage at approximately3 kV per second and hold for 3 min.7.3.3.3 Measure and record the leakage current.Aleakage inexcess of 2 microamps per kB of test voltage signifies a fai
30、lure.7.3.4 The link shall be tested to verify that it has a waterrepellent surface.7.3.4.1 Immerse the entire link completely in a tank undertap water at room temperature for a minimum of 1 min.7.3.4.2 In the vertical use position allow to set for 2 min toallow water to run off.7.3.4.3 Apply DC test
31、 voltage in accordance with Table 1within a time frame of 5 min after wetting. Increase voltage atapproximately 3 kV per second and hold for 3 min.7.3.4.4 Measure and record the leakage current.Aleakage inexcess of 2 microamps per kV of test voltage signifies a failure.8. Manufacturer Proof Tests8.1
32、 Mechanical Proof Test Procedure:8.1.1 Each unit manufactured shall be subjected to anappropriate tensile proof load based on its rated load (see Table2) for 60 s without permanent deformation. The load will beincreased gradually in not less than 1 min. When requested, themanufacturer shall supply c
33、ertification of compliance by unitserial number to the purchaser.8.2 Electrical Proof Test Procedure:8.2.1 General test requirements are given in 6.2 6.6.8.2.2 An electrical proof test will be performed by themanufacturer on each insulating link before purchase. A copyof the proof test report will b
34、e kept on file by the manufacturerand made available to the customer upon request.8.2.3 Electrically test the insulating link under dryconditions, applying two times the rated link voltage. Testvoltages for typical voltage ratings are listed in Table 1.8.2.4 Test current shall be no more than 3 mA a
35、nd thereshall be no sign of flashover or tracking.9. Field Care, Inspection and Maintenance9.1 Frequent Inspections:9.1.1 Insulating lifting links shall be inspected at frequentintervals.(a) Installation on lifting device when installed.(b) Daily before first use.9.1.2 Frequent InspectionVisual insp
36、ections by the opera-tor or other designated personnel.(a) Frequent inspections shall include observations duringoperation.(b) Links shall be inspected for distortion, cracks, nicks,gouges in the meal ends and damage to the insulating surfacesuch as cracks, nicks, or punctures. A designated person s
37、halldetermine whether conditions found during the inspectionconstitute a hazard and whether more detailed inspections arerequired. Cracks and other visible surface damage whosedepths reach the link core will be cause for rejection and thelink shall be removed from service and returned to themanufact
38、urer for repair or replacement.(c) In any condition that would moisten or wet the surface(dew, mist, rain, etc) links should be inspected for contamina-tion that absorbs water over 20 % of the length of the link.Clean with a nonabrasive cleaner before returning to service.(d) In any condition that w
39、ould moisten or wet the surface(dew, mist, rain, etc.) links should be inspected for waterrepelling surface.Apply water by spraying or pouring to ensureit beads up as in HC1HC2 of Fig. 2. If the surface wets orshows poor beading pattern as in HC5 and HC6 of Fig. 2, thelink surface should be cleaned
40、and waxed with a waterrepelling nonconductive coating such as carnuba wax.9.2 Periodic Inspections:9.2.1 Insulating lifting links shall be inspected at periodicintervals.(a) A periodic inspection shall be performed annually.(b) A periodic inspection shall be performed when anextraordinary event occu
41、rs, such as a sudden release of load,TABLE 1 Test Voltages for Typical Voltage RatingsNOTE 1Insulating links manufactured with rated voltages other thanlisted can have their test voltages calculated by using the formulascontained in the tables. (AC 2)Acceptance currents are 3 mAmaximum.RatedLink Vol
42、t-age AC(RLV), kVLine toGroundEquiva-lent RLV/squareroot of 3(1.732),kVTest Volt-age (AC)RLV2AC Maxi-mumLeakagein milli-amps notto exceed3mATest Volt-age DCkV AC 1.4DC Maxi-mumLeakage,in micro-amps25 15 30 3 mA 42 4235 20 40 3 mA 56 5650 29 58 3 mA 81 8169 40 80 3 mA 112 11275 43 86 3 mA 120 120125
43、72 144 3 mA 202 202175 101 202 3 mA 283 283TABLE 2 Tensile Proof Load Based on Its Rated Load forManufactured Unit in TonsRated Load Proof Test Load as % of Rated LoadBelow 54 tons 20067 tons 19390 tons 183112 tons 166135 tons 150136 tons and above 133F2973 143abnormal impact, lightning strike, vand
44、alism, or any suspectedoccurrence of possible damage to the insulating link. Themanufacturer should be consulted to aid in evaluation anddetermination if suitable for continued use.9.2.2 Periodic inspections are visual inspections of apparentexternal conditions by a designated person.9.2.2.1 The per
45、iodic inspection shall include a detailedinspection of items listed in 9.1.2, Frequent Inspection. Whenthe inspection indicates there may be reason to suspect theelectrical or mechanical integrity of the link it shall bemechanically and electrically tested in accordance with Section10 before return
46、to service.9.3 Care and Maintenance:9.3.1 The link surface should be cleaned to remove anyaccumulations of dirt or contamination such as salt and dustparticles.9.3.2 Links should be waxed on an annual basis or asneeded to ensure water beading with a carnauba wax tomaintain its water shedding capabil
47、ity. Water should bead upon the link surface. See representative photos. Fig. 2(HC1HC2) show good beading pattern. HC3 and HC4 showpoor beading pattern with continuous rivulets that could causeelectrical failure.9.3.3 Nicks and gouges to the surface may be repairedfollowing the link manufacturers re
48、commendations.9.3.4 When not in use, insulating links should be stored outof the elements following the link manufacturers recommen-dations.9.3.5 Any alteration of the insulating link from the originalmanufacturers design or repair without accompanying writtenapproval from the manufacturer is prohib
49、ited and will be causefor the link being removed from service.10. In-Service Tests for Insulating Link10.1 Mechanical In-Service Test Procedure:10.1.1 When the frequent or periodic inspection indicatesthat there may be reason to suspect mechanical integrity, thelink shall be removed from service and a mechanical proof loadtest shall be performed before continued use.10.1.2 The insulating link shall withstand a tensile load of1.25 times the rate load of the link as measured by a calibrateddynamometer or load cell, with the link in place on the loadl
