ASTM F855-17 Standard Specifications for Temporary Protective Grounds to Be Used on De-energized Electric Power Lines and Equipment.pdf

1、Designation: F855 17Standard Specifications forTemporary Protective Grounds to Be Used on De-energizedElectric Power Lines and Equipment1This standard is issued under the fixed designation F855; the number immediately following the designation indicates the year of originaladoption or, in the case o

2、f revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These specifications cover the equipment making up thetemporary grounding system used on de-energi

3、zed electricpower lines, electric supply stations, and equipment.1.2 It is common practice for the users of protectivegrounding equipment to prepare complete instructions andregulations to govern in detail the correct use and maintenanceof such equipment.1.3 The uses and maintenance of this equipmen

4、t are beyondthe scope of these specifications.1.4 These specifications for a system of protective ground-ing utilizing copper cables are covered in four parts, as follows:SectionsClamps for Temporary Protective Grounds 416Ferrules for Temporary Protective Grounds 1730Cables for Temporary Protective

5、Grounds 3139Protective Grounds (Complete Assembly With Clamps, Ferrules,and Cable)40521.5 Each of the four parts is an entity of itself, but is listedas a part of the system for completeness and clarification.1.6 Currents presented in Table 1 are based upon cablemelting times, as determined from equ

6、ations by I. M. Onder-donk and are to used in situations involving an asymmetryvalue less than 20 % (X/R 1.8). See Appendix X1.1.6.1 Currents presented in Table 2 are based upon thevalues from EPRI Project RP2446 Computer Program RTGC“A Desktop Computer Program for Calculating Rating ofTemporary Gro

7、unding Cables” and are to be used in situationsinvolving an asymmetry value greater then 20 % (X/R 1.8),see Appendix X2.NOTE 1Table 1 represents the clamp and assembly ratings that existedprior to this revision. Table 2 represents new ratings now required for highX/R situations.1.6.2 See Appendix X1

8、 and Appendix X2 for a discussionof these topics.1.7 The values stated in Newton-Meter units are to beregarded as the standard. The values in parentheses are theinch-pound units.1.8 The following precautionary caveat pertains to the testmethod portions, Sections 12 and 25 of these specifications:Thi

9、s standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety,health, and environmental practices and determine the appli-cability of regulatory limitations prior to use.1.9 This

10、 international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (

11、TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B172 Specification for Rope-Lay-Stranded Copper Conduc-tors Having Bunch-Stranded Members, for Electrical Con-ductorsB173 Specification for Rope-Lay-Stranded Copper Conduc-tors Having Concentric-Stranded Members, for ElectricalConductorsD470

12、Test Methods for Crosslinked Insulations and Jacketsfor Wire and CableD753 Specification for General Purpose PolychloropreneJacket for Wire and Cable (Withdrawn 1984)3D2219 Specification for Poly(Vinyl Chloride) Insulation forWire and Cable, 60C OperationD2633 Test Methods for Thermoplastic Insulati

13、ons andJackets for Wire and CableD2768 Specification for General-Purpose Ethylene-Propylene Rubber Jacket for Wire and Cable (Withdrawn2007)31These specifications are under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and are the direct responsibility ofSubcom

14、mittee F18.45 on Mechanical Apparatus.Current edition approved Dec. 15, 2017. Published January 2018. Originallyapproved in 1983. Last previous edition approved in 2015 as F855 15. DOI:10.1520/F0855-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv

15、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons

16、hohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Or

17、ganization Technical Barriers to Trade (TBT) Committee.1D2770 Specification for Ozone-Resisting Ethylene-Propylene Rubber Integral Insulation and Jacket for Wireand Cable (Withdrawn 2007)3E8/E8M Test Methods for Tension Testing of Metallic Ma-terials2.2 ANSI Standard:4C 37.09 Standard Test Procedure

18、 for AC High-VoltageCircuit Breakers Rated on a Symmetrical Basis2.3 ICEA/NEMA Standard:5ICEA S-19-81/NEMA WC 3-80 (R 1986) Rubber InsulatedWire and Cable for the Transmission and Distribution ofElectrical Energy2.4 IEC Standard:6IEC 61230 Ed. 2, 2008, Portable Equipment for Earthing orEarthing and

19、Short-Circuiting2.5 IEEE Standard:7IEEE 386 Standard for Separable Insulated Connector Sys-tems for Power Distribution Systems Above 600VIEEE 1048 Guide for Protective Grounding of Power LinesIEEE 1246 Guide for Temporary Protective Grounding Sys-tems Used in Substations3. Terminology3.1 Definitions

20、 of Terms Specific to This Standard:3.1.1 continuous current ratingdesignated RMS currentwhich can be carried continuously under specified conditions.3.1.2 protective ground assemblya temporary electricalconnection between a source of potential energization and theearth, rated for the maximum antici

21、pated fault current orcontinuous induced current, or both.3.1.2.1 DiscussionThroughout this specification, kcmil = 1000 circular mils.3.1.3 protective grounding equipmentdevices installedtemporarily on de-energized electric power circuits for thepurposes of potential equalization and to conduct a sh

22、ort circuitcurrent for a specified duration (time).3.1.4 time to failurefailure time of the cable is the timebetween the initiation of current flow and the instant at whicharcing begins.3.1.5 ultimate capacitythis represents a current which it iscalculated the component is capable of conducting for

23、thespecified time. It is expected that component damage mayresult. The component shall not be reused, except in testsituations.3.1.6 withstand ratingthis represents a near symmetricalcurrent which shall be conducted without any component beingdamaged sufficiently to prevent being operable and reusab

24、le.The protective ground shall be capable of passing a second testat this current after being cooled to ambient temperature.4Available from American National Standards Institute, 11 West 42nd St., 13thFloor, New York, NY 10036.5Available from Insulated Cable EngineersAssoc., P.O. Box P, South Yarmou

25、th,MA 02664.6Available from International Electrotechnical Commission (IEC), 3 rue deVaremb, Case postale 131, CH-1211, Geneva 20, Switzerland, http:/www.iec.ch.7Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http

26、:/www.ieee.org.TABLE 1 Protective Ground Cable, Ferrule, Clamp and Assembly Ratings for Symmetrical CurrentGradeGrounding Clamp TorqueStrength, minShort Circuit PropertiesAContinuousCurrentRating, ARMS, 60HzYieldBUltimateWithstand Rating, SymmetricalkARMS, 60 HzUltimate Rating CapacityCD, Symmetrica

27、lkARMS, 60 Hzlbfin. nm lbfin. nm15cycles(250 ms)30 cycles(500ms)Copper CableSize15cycles(250ms)30cycles(500ms)60cycles(1 s)MaximumCopper TestCable Size1 280 32 330 37 14 10 #2 18 13 9 2/0 2002 280 32 330 37 21 15 1/0 29 21 14 4/0 2503 280 32 330 37 27 20 2/0 37 26 18 4/0 3004 330 37 400 45 34 25 3/0

28、 47 33 23 250 kcmil 3505 330 37 400 45 43 30 4/0 59 42 29 250 kcmil 4006 330 37 400 45 54 39 250 kcmil or22/070 49 35 350 kcmil 4507 330 37 400 45 74 54 350 kcmil or24/098 69 48 550 kcmil 550AWithstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asym

29、metry factor (see 9.1 and 12.3.4.2).BYield shall mean no permanent deformation such that the clamp cannot be reused throughout its entire range of application.CUltimate rating represents a symmetrical current which the assembly or individual components shall carry for the specified time.DUltimate va

30、lues are based upon application of Onderdonks equation to 98 % of nominal circular mil area allowed by Specifications B172 and B173.NOTE 1TPG testing is done on complete assemblies. Assembly ratings assume the grade of lowest graded component (see 43.1.6).F855 172TABLE2UltimateAssemblyRatingforHighX

31、/RRatioApplicationsGradeSizeRating RatedCurrent(kA)HighAsymmetricalTestRequirementsX/R=30CycleCurrentPeakValues(kA)RatingX2.69TestDuration(cycles)12t(Megaamps2-s)1st2nd3rd4th5th6th7th8th9th10th11th12th13th14th15th1H1541373432302827262525242423232315742H25686257535047454342414039383838152083H31847670

32、656158565352504948474746153124H391059688827773706765636261605958155015H47127116106999388848178767473727170157286H55148135124116109103989491898785848382159977H68183167154143134127121117113110107105104102101151523NOTE1Theabovecurrentvaluesarebasedonelectromechanicaltestvalues.NOTE2Assembliesthathavebe

33、ensubjectedtotheseshallnotbere-used.NOTE3Forusewithcurrentsexceeding20%asymmetryfactor.NOTE4SeeX2.7.2foradditionalinformation.NOTE5Alternatetestingcircuitsareavailableforlaboratoriesthatcannotachievetheaboverequirements.SeeAppendixX2fordetails.F855 173CLAMPS FOR TEMPORARY PROTECTIVEGROUNDS4. Scope4.

34、1 This specification covers clamps used with ferrules andelastomer or thermoplastic covered flexible cable in the manu-facture of protective grounds installed temporarily for protec-tive grounding of de-energized circuits.5. Classification5.1 Clamps are furnished in, but not limited to, three typesa

35、ccording to their function and method of installation, asfollows:5.1.1 Type IClamps for installation on de-energized con-ductors equipped with eyes for installation with removable hotsticks.5.1.2 Type IIClamps for installation on de-energized con-ductors having permanently mounted hot sticks.5.1.3 T

36、ype IIIClamps for installation on permanentlygrounded conductors or metal structures with tee handles, andeyes or square or hexagon head screw(s), or both.5.1.4 Other types of special clamps, such as those for clustergrounds or for underground equipment grounding, may bemade, tested, and certified b

37、y the manufacturer as meeting therequirements of this specification.5.1.5 Separable insulated connectors used in manufacturingunderground equipment grounding assemblies shall meet therequirements of IEEE 386.5.2 Clamps are furnished in grades according to mechanicalstrengths, short circuit capabilit

38、ies, and duration of faults, asindicated in Table 1 or Table 2. For Table 1 grade designations,clamp ratings must include maximum use current and indica-tion whether testing was done at Ultimate or WithstandRatings. The maximum use current listed shall not exceed thetest current used in their electr

39、ical short circuit design tests (per12.3.4).5.3 Clamps are furnished in two classes according to thecharacteristics of the main contact jaws:5.3.1 Class AClamp jaws with smooth contact surfaces.5.3.2 Class BClamp jaws with serrations, or crosshatching, or other means intended to abrade or bite throu

40、ghcorrosion products on the surfaces of the conductor beingclamped.6. Sizes6.1 Clamp size is the combination of the main contact andcable size ranges as listed by the manufacturers. It should benoted that the main contact may connect to a cable or bus baror be used at the “ground end” to connect to

41、a variety ofconductive grounded objects.7. Ordering Information7.1 Orders for clamps under this specification shall includethis ASTM designation and the following information:7.1.1 Quantity,7.1.2 Name (grounding clamp),7.1.3 Main contact size ranges, conductor descriptions, andmaterials which are to

42、 be clamped by main contact,7.1.4 Cable size, material, and description by which clampsare to be assembled,7.1.5 Type (see 5.1),7.1.6 Grade (see 5.2 and Table 1 or Table 2),7.1.7 Class (see 5.3),7.1.8 Asymmetrical current or other supplementaryrequirements, if applicable. (See Supplementary Requirem

43、entsS1 to S10 for styles and designs.)NOTE 2A typical ordering description is as follows: 100 GroundingClamps, Main contact range #2 to 350 kcmil for 2/0 Copper flexiblegrounding cable, ASTM F855, Type 1, Grade 3, Class A, Design C, Style7.NOTE 3It is expected that manufacturers will publish catalog

44、 dataconforming to this specification that will combine the requirements of7.1.1 7.1.8 in a single product number. With that system, a typical orderdescription is: 100 (Smith Manufacturing Co. Product No. XXXX)grounding clamps ASTM F855, Grade 2-max use 21kA, Ultimate Rating.8. Materials8.1 Current

45、carrying parts made of copper base or aluminumbase alloy shall have the following material properties inaccordance with Test Methods E8/E8M:Copper Base Alloy Aluminum Base AlloyTensile strength, min 207 MPa (30 000 psi) 207 MPa (30 000 psi)Yield strength, min 90 MPa (13 000 psi) 138 MPa (20 000 psi)

46、Elongation, min 6 % 3 %8.2 Type II clamps shall be equipped with an insulatinghandle (hot stick) appropriate for the nominal voltage of thecircuit to be grounded.9. Electrical and Mechanical Properties9.1 Electrical and mechanical properties shall conform tothe requirements prescribed in Table 1 or

47、Table 2,asappropriate, and the following paragraphs. See Appendix X1for a discussion and derivation of the current levels in Table 1.See Appendix X2 for a discussion of the effects of asymmetri-cal current and the derivation of the currents in Table 2.9.1.1 Types I and II stick installed clamps shal

48、l be designedsuch that a failure does not increase the risk of injury to theuser or have excess mechanical strength to prevent failure,defined as follows:9.1.1.1 In the event the clamp is over-torqued duringinstallation, normal fracture shall be such that the attachedcable remains under control by b

49、eing retained with the stick.9.1.1.2 Clamps with an ultimate torque strength exceeding45 Nm (400 lbfin.) are exempt from the provisions of 9.1.1.1.9.1.2 Resistance from the main contact to the attached cablecontact shall be less than that for an equal length of maximumsize cable(s) for which the clamp is rated.9.1.3 Main contacts shall accept and clamp all conductors orstructural members in accordance with the manufacturersrating.9.1.4 Clamp shall accept hand assembly of all cables fittedwith compatible ferrules as rated per Table 3.9.1.5