ASTM F855-2004 Standard Specifications for Temporary Protective Grounds to Be Used on De-energized Electric Power Lines and Equipment《断开的电力线及设备上使用的临时保护性接地装置的标准规范》.pdf

1、Designation: F 855 04Standard Specifications forTemporary Protective Grounds to Be Used on De-energizedElectric Power Lines and Equipment1This standard is issued under the fixed designation F 855; the number immediately following the designation indicates the year oforiginal adoption or, in the case

2、 of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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

3、-energized 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 e

4、quipment 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 4-16Ferrules for Temporary Protective Grounds 17-30Cables for Temporary Pr

5、otective Grounds 31-39Protective Grounds (Complete Assembly With Clamps, Ferrules,and Cable)40-521.5 Each of the four parts is an entity of itself, but is listedas a part of the system for completeness and clarification.1.6 The values stated in Newton-Meter units are to beregarded as the standard. T

6、he values in parentheses are theinch-pound units.1.7 Currents presented in Table 1 and Table 2 are basedupon cable melting times, as determined from equations by I.M. Onderdonk. See Appendix X3.1.7.1 Currents presented in Table 3 were determined by useof EPRI Project RP2446 Computer Program RTGC “A

7、Desk-top Computer Program for Calculating Rating of TemporaryGrounding Cables.”1.7.2 SeeAppendix X3 andAppendix X4 for a discussion ofthese values.1.8 The following precautionary caveat pertains to the testmethod portions, Sections 12 and 25 of these specifications:This standard does not purport to

8、address all of the safetyconcerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B 172 Specific

9、ation for Rope-Lay-Stranded Copper Con-ductors Having Bunch-Stranded Members, for ElectricalConductorsB 173 Specification for Rope-Lay-Stranded Copper Con-ductors Having Concentric-Stranded Members, for Elec-trical ConductorsB 263 Test Method for Determination of Cross-SectionalArea of Stranded Cond

10、uctorsD 470 Test Methods for Cross-linked Insulations and Jack-ets for Wire and CableD 753 Specification for General-Purpose PolychloropreneJacket for Wire and CableD 2219 Specification for Poly(Vinyl Chloride) Insulationfor Wire and Cable, 60 OperationD 2633 Methods of Testing Thermoplastic Insulat

11、ions andJackets for Wire and CableD 2768 Specification for General-Purpose Ethylene Propy-lene Rubber Jacket for Wire and CableD 2770 Specification for Ozone-Resisting Ethylene Propy-lene Rubber Integral Insulation and Jacket for Wire andCableE 8 Test Methods of Tension Testing of Metallic Materials

12、2.2 ANSI Standard:C 37.09 Standard Test Procedure for AC High-VoltageCircuit Breakers Rated on a Symmetrical Basis32.3 ICEA/NEMA Standard:ICEA S-19-81/NEMA WC 80 (R 1986) Rubber InsulatedWire and Cable for the Transmission and Distribution ofElectrical Energy42.4 IEC Standard:1These specifications a

13、re under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and are the direct responsibility ofSubcommittee F18.45 on Mechanical Apparatus.Current edition approved Sept. 1, 2004. Published September 2004. Originallyapproved in 1983. Last previous edition approved i

14、n 2003 as F 855 03.2For 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 American National Standard

15、s Institute, 11 West 42nd St., 13thFloor, New York, NY 10036.4Available from Insulated Cable EngineersAssoc., P.O. Box P, South Yarmouth,MA 02664.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.IEC 1230 Portable Equipment for Earthin

16、g or Earthing andShort-Circuiting (currently under review)52.5 IEEE Standard:IEEE 386 Standard for Separable Insulated Connector Sys-tems for Power Distribution Systems Above 600V3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 continuous current ratingdesignated RMS currentwhi

17、ch 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 anticipated fault current orcontinuous induced current, or both.3.1.2.1 DiscussionThroughout this

18、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 short circuitcurrent for a specified duration (time).3.1.4 time to failurefailure time of the

19、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 thespecified time. It is expected that component damage mayresult. The component shall not b

20、e 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 reusable.The protective ground shall be capable of passing a second testat this current after bein

21、g cooled to ambient temperature.CLAMPS FOR TEMPORARY PROTECTIVEGROUNDS4. Scope4.1 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 circuit

22、s.5Available from IEC.TABLE 1 Protective Ground Clamp RatingsGradeGrounding Clamp TorqueStrength, minShort Circuit PropertiesAContinuousCurrentRating, ARMS, 60HzMinimum Ca-ble Size withFerrule In-stalled Equalor LargerThanYieldBUltimateWithstand Rating, SymmetricalkARMS, 60 HzUltimate Rating/Capacit

23、y,CDSymmetricalkARMS, 60 Hzlbfin. nm lbfin. nm15cycles(250 ms)30 cycles(500ms)Copper CableSize6 cycles(100 ms)15cycles(250ms)30cycles(500ms)60cycles(1 s)MaximumCopper TestCable Size1 280 32 330 37 14 10 #2 29 18 13 9 2/0 200 #22 280 32 330 37 21 15 1/0 47 29 21 14 4/0 250 1/03 280 32 330 37 27 20 2/

24、0 58 37 26 18 4/0 300 2/04 330 37 400 45 34 25 3/0 74 47 33 23 250 kcmil 350 3/05 330 37 400 45 43 30 4/0 94 59 42 29 250 kcmil 400 4/06 330 37 400 45 54 39 250 kcmil or2 2/0111 70 49 35 350 kcmil 450 250 kcmilor 2 2/07 330 37 400 45 74 54 350 kcmil or2 4/0155 98 69 48 550 kcmil 550 350 kcmilor 2 4/

25、0AWithstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asymmetry 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 s

26、ymmetrical current which the clamp shall carry for the specified time.DUltimate values are based upon application of Onderdonks equation to 98 % of nominal circular mil area allowed by Specifications B 172 and B 173.TABLE 2 Protective Ground Cable Ferrule, and Assembly RatingsGrade Cable SizeShort C

27、ircuit PropertiesASymmetrical kA RMS 60 HzContinuous Cur-rent Rating, RMS60 HzWithstand Rating Ultimate Rating/CapacityB,C15 cycles(250 ms)30 cycles(500 ms)6 cycles(100 ms)15 cycles(250 ms)30 cycles(500 ms)60 cycles(1 s)1 2 14 10 28 18 13 9 2002 1/0 21 15 47 29 21 14 2503 2/0 27 20 59 37 26 18 3004

28、3/0 34 25 74 47 33 23 3505 4/0 43 30 94 59 42 29 4006 250 kcmil 54 39 111 70 49 35 4507 350 kcmil 74 54 155 98 69 49 550AWithstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asymmetry factor (see 9.1 and 12.3.4.2).BUltimate rating represents a symme

29、trical current which the ferrule shall carry for the time specified.CUltimate value based upon application of Onderdonks equation to 98 % of nominal circular mil area allowed by Specifications B 172 and B 173.F8550425. Classification5.1 Clamps are furnished in, but not limited to, three typesaccordi

30、ng 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 Type II

31、IClamps 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 by the

32、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 capabilities, a

33、nd duration of faults, asindicated in Table 1.5.3 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 cross hatch-ing, or other means intended to abrade or bite t

34、hroughcorrosion 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

35、 to 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 ar

36、e to 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),7.1.7 Class (see 5.3), and7.1.8 Asymmetrical current or other supplementary require-ments, if applicable. (See Supplementary Requireme

37、nts S1 toS10 for styles and designs.)TABLE 3 Ultimate Current Carrying Capabilities of Copper Grounding Cable Derived from EPRI RP2446TABLE 3a Worst Case: X/R = 40; DC Offset = 92 %, Kiloamperes, Asymmetrical, RMS, 60 HzCopper GroundingCable Size, AWGNominal CrossSection, mm26 Cycles(100 ms)15 Cycle

38、s(250 ms)30 Cycles(500 ms)45 Cycles(750 ms)60 Cycles(1 s)Continuous CurrentRating, RMS, 60Hz#2 33.63 23 17 13 11 9 2001/0 53.48 36 26 20 17 15 2502/0 67.42 46 33 26 21 19 3003/0 85.03 57 42 32 27 24 3504/0 107.2 72 53 41 34 30 400250 kcmil 126.65 86 63 48 40 35 450350 kcmil 177.36 120 88 67 56 50 55

39、0Table 3b Midrange: X/R = 10; DC Offset = 74 %, Kiloamperes, Asymmetrical, RMS, 60 HzCopper GroundingCable Size, AWGNominal CrossSection, mm26 Cycles(100 ms)15 Cycles(250 ms)30 Cycles(500 ms)45 Cycles(750 ms)60 Cycles(1 s)Continuous CurrentRating, RMS, 60Hz#2 33.63 28 19 14 11 10 2001/0 53.48 44 30

40、22 18 16 2502/0 67.42 57 38 27 23 20 3003/0 85.03 71 48 35 28 25 3504/0 107.2 89 60 44 36 31 400250 kcmil 126.65 105 71 51 42 37 450350 kcmil 177.36 147 100 72 59 52 550Table 3c Best Case: X/R = 0; DC Offset=0%,Kiloamperes, Asymmetrical, RMS, 60 HzCopper GroundingCable Size, AWGNominal CrossSection,

41、 mm26 Cycles(100 ms)15 Cycles(250 ms)30 Cycles(500 ms)45 Cycles(750 ms)60 Cycles(1 s)Continuous CurrentRating, RMS, 60Hz#2 33.63 31 20 14 11 10 2001/0 53.48 50 32 22 18 16 2502/0 67.42 63 40 28 23 20 3003/0 85.03 79 50 35 29 25 3504/0 107.2 100 63 45 36 32 400250 kcmil 126.65 118 75 53 43 37 450350

42、kcmil 177.36 165 104 74 60 52 550F855043NOTE 1A 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 2, Class A, Design C, Style7, or X/R maximum, in addition to the grade designation.NOTE

43、 2It is expected that manufacturers will publish catalog dataconforming to this specification that will combine the requirements of7.1.2-7.1.8 in a single product number. With that system, a typical orderdescription is: 100 (Smith Manufacturing Co. Product No. XXXX)grounding clamps ASTM F855, Grade

44、2.8. Materials8.1 Current carrying parts made of copper base or aluminumbase alloy shall have the following material properties inaccordance with Test Methods E 8: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 ps

45、i) 138 MPa (20 000 psi)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 pr

46、escribed in Table 1 or Table 3, as appropri-ate, and the following paragraphs. See Appendix X3 for adiscussion and derivation of the current levels. See AppendixX4 for a discussion of the effects of asymmetrical current.9.1.1 Types I and II stick installed clamps shall be designedsuch that a failure

47、 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 during instal-lation, normal fracture shall be such that the attached cableremains under control by being retained with the stick.9

48、.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 contact

49、s 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 2 (see Table 2 andTable 4).9.1.5 Cable termination shall include a cable support orshall be made to accept a cable supporting ferrule. This supportshall secure the entire cable over the jacket and is provided inaddition to the electrical connection to the strand.9.1.6 Type I clamps shall be operable with clamp sticks andshall fit securely inside a nominal 1