ASTM F855-14
(Specification)Standard Specifications for Temporary Protective Grounds to Be Used on De-energized Electric Power Lines and Equipment
Standard Specifications for Temporary Protective Grounds to Be Used on De-energized Electric Power Lines and Equipment
ABSTRACT
These specifications cover the equipment making up the temporary grounding system used on de-energized electric power lines, electric supply stations, and equipment. These specifications for a system of protective grounding utilizing copper cables are covered in four parts, as follows: clamps, ferrules, cables, and temporary protective grounds. Each of the four parts is an entity of itself, but is listed as a part of the system for completeness and clarification. The clamps shall be subject to design tests for determining mechanical torque strength and electrical short circuit capacity. The ferrules shall be tested for electrical short-circuit capacity and continuous current rating. The elastomer or thermoplastic making up the jacket of the flexible cable shall be tested according to the specified methods.
SCOPE
1.1 These specifications cover the equipment making up the temporary grounding system used on de-energized electric power lines, electric supply stations, and equipment.
1.2 It is common practice for the users of protective grounding equipment to prepare complete instructions and regulations to govern in detail the correct use and maintenance of such equipment.
1.3 The uses and maintenance of this equipment are beyond the scope of these specifications.
1.4 These specifications for a system of protective grounding utilizing copper cables are covered in four parts, as follows:
Sections
Clamps for Temporary Protective Grounds
4 – 16
Ferrules for Temporary Protective Grounds
17 – 30
Cables for Temporary Protective Grounds
31 – 39
Protective Grounds (Complete Assembly With Clamps, Ferrules, and Cable)
40 – 52
1.5 Each of the four parts is an entity of itself, but is listed as a part of the system for completeness and clarification.
1.6 Currents presented in Table 1 are based upon cable melting times, as determined from equations by I. M. Onderdonk and are to used in situations involving an asymmetry value less than 20 % (X/R ≤ 1.8). See Appendix X3. (A) Withstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asymmetry factor (see 9.1 and 12.3.4.2).(B) Yield shall mean no permanent deformation such that the clamp cannot be reused throughout its entire range of application.(C) Ultimate rating represents a symmetrical current which the assembly or individual components shall carry for the specified time.(D) Ultimate values are based upon application of Onderdonk's equation to 98 % of nominal circular mil area allowed by Specifications B172 and B173.
1.6.1 Currents presented in Table 2 are based upon the values from EPRI Project RP2446 Computer Program RTGC “A Desktop Computer Program for Calculating Rating of Temporary Grounding Cables” and are to be used in situations involving an asymmetry value greater then 20 % (X/R ≧ 1.8), see Appendix X4.
Note 1: The above current values are based on electromechanical test values.
Note 2: Assemblies that have been subjected to these shall not be re-used.
Note 3: For use with currents exceeding 20 % asymmetry factor.
Note 4: See X4.7.2 for additional information.
Note 5: Alternate testing circuits are available for laboratories that cannot achieve the above requirements. See Appendix X4 for details.
Note 1: Table 1 represents the clamp and assembly ratings that existed prior to this revision. Table 2 represents new ratings now required for high X/R situations.
1.6.2 See Appendix X3 and Appendix X4 for a discussion of these topics.
1.7 The values stated in Newton-Meter units are to be regarded as the standard. The values in parentheses are the inch-pound units.
1.8 The following precautionary caveat pertains to the test method portions, Sections 12 and 25 of these specifications: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the respon...
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Designation:F855 −14
StandardSpecifications for
Temporary Protective Grounds to Be Used on De-energized
Electric Power Lines and Equipment
ThisstandardisissuedunderthefixeddesignationF855;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.7 The values stated in Newton-Meter units are to be
regarded as the standard. The values in parentheses are the
1.1 Thesespecificationscovertheequipmentmakingupthe
inch-pound units.
temporary grounding system used on de-energized electric
1.8 The following precautionary caveat pertains to the test
power lines, electric supply stations, and equipment.
method portions, Sections 12 and 25 of these specification-
1.2 It is common practice for the users of protective
s:This standard does not purport to address all of the safety
grounding equipment to prepare complete instructions and
concerns, if any, associated with its use. It is the responsibility
regulations to govern in detail the correct use and maintenance
of the user of this standard to establish appropriate safety and
of such equipment.
health practices and determine the applicability of regulatory
1.3 Theusesandmaintenanceofthisequipmentarebeyond
limitations prior to use.
the scope of these specifications.
2. Referenced Documents
1.4 These specifications for a system of protective ground-
ingutilizingcoppercablesarecoveredinfourparts,asfollows:
2.1 ASTM Standards:
B172Specification for Rope-Lay-Stranded Copper Conduc-
Sections
torsHavingBunch-StrandedMembers,forElectricalCon-
Clamps for Temporary Protective Grounds 4–16
ductors
Ferrules for Temporary Protective Grounds 17–30
Cables for Temporary Protective Grounds 31–39
B173Specification for Rope-Lay-Stranded Copper Conduc-
Protective Grounds (Complete Assembly With Clamps, Ferrules, 40–52
tors Having Concentric-Stranded Members, for Electrical
and Cable)
Conductors
1.5 Each of the four parts is an entity of itself, but is listed
D470Test Methods for Crosslinked Insulations and Jackets
as a part of the system for completeness and clarification.
for Wire and Cable
1.6 Currents presented in Table 1 are based upon cable D753Specification for General Purpose Polychloroprene
melting times, as determined from equations by I. M. Onder-
Jacket for Wire and Cable (Withdrawn 1984)
donk and are to used in situations involving an asymmetry D2219Specification for Poly(Vinyl Chloride) Insulation for
value less than 20 % (X/R ≤ 1.8). See Appendix X3.
Wire and Cable, 60°C Operation
1.6.1 Currents presented in Table 2 are based upon the D2633Test Methods for Thermoplastic Insulations and
values from EPRI Project RP2446 Computer Program RTGC
Jackets for Wire and Cable
“A Desktop Computer Program for Calculating Rating of
D2768 Specification for General-Purpose Ethylene-
Temporary Grounding Cables” and are to be used in situations
Propylene Rubber Jacket for Wire and Cable (Withdrawn
involving an asymmetry value greater then 20 % (X/R^ 1.8),
2007)
see Appendix X4.
D2770 Specification for Ozone-Resisting Ethylene-
Propylene Rubber Integral Insulation and Jacket for Wire
NOTE1—Table1representstheclampandassemblyratingsthatexisted
and Cable (Withdrawn 2007)
priortothisrevision.Table2representsnewratingsnowrequiredforhigh
X/R situations. E8/E8MTest Methods for Tension Testing of Metallic Ma-
terials
1.6.2 See Appendix X3 and Appendix X4 for a discussion
of these topics.
1 2
These specifications are under the jurisdiction of ASTM Committee F18 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Electrical Protective Equipment for Workers and are the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee F18.45 on Mechanical Apparatus. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2014. Published November 2014. Originally the ASTM website.
approved in 1983. Last previous edition approved in 2009 as F855–09. DOI: The last approved version of this historical standard is referenced on
10.1520/F0855-14. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F855−14
TABLE 1 Protective Ground Cable, Ferrule, Clamp and Assembly Ratings for Symmetrical Current
Grounding Clamp Torque
A
Short Circuit Properties
Strength, min
CD
Withstand Rating, Symmetrical Continuous
Ultimate Rating Capacity , Symmetrical
B
Yield Ultimate kA kA Current
RMS, 60 Hz
Grade RMS, 60 Hz Rating, A
RMS, 60
15 30
15 30 cycles 60 Maximum
Hz
Copper Cable cycles cycles
lbf·in. n·m lbf·in. n·m cycles (500 cycles Copper Test
Size (250 (500
(250 ms) ms) (1 s) Cable Size
ms) ms)
1 280 32 330 37 14 10 #2 18 13 9 2/0 200
2 280 32 330 37 21 15 1/0 29 21 14 4/0 250
3 280 32 330 37 27 20 2/0 37 26 18 4/0 300
4 330 37 400 45 34 25 3/0 47 33 23 250 kcmil 350
5 330 37 400 45 43 30 4/0 59 42 29 250 kcmil 400
6 330 37 400 45 54 39 250 kcmil or 70 49 35 350 kcmil 450
22/0
7 330 37 400 45 74 54 350 kcmil or 98 69 48 550 kcmil 550
24/0
A
Withstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asymmetry factor (see 9.1 and 12.3.4.2).
B
Yield shall mean no permanent deformation such that the clamp cannot be reused throughout its entire range of application.
C
Ultimate rating represents a symmetrical current which the assembly or individual components shall carry for the specified time.
D
Ultimate values are based upon application of Onderdonk’s equation to 98 % of nominal circular mil area allowed by Specifications B172 and B173.
2.2 ANSI Standard: 3.1.3 protective grounding equipment—devices installed
C 37.09 Standard Test Procedure for AC High-Voltage temporarily on de-energized electric power circuits for the
Circuit Breakers Rated on a Symmetrical Basis purposesofpotentialequalizationandtoconductashortcircuit
current for a specified duration (time).
2.3 ICEA/NEMA Standard:
ICEAS-19-81/NEMAWC 3-80 (R1986) Rubber Insulated
3.1.4 time to failure—failure time of the cable is the time
Wire and Cable for the Transmission and Distribution of
between the initiation of current flow and the instant at which
Electrical Energy
arcing begins.
2.4 IEC Standard:
3.1.5 ultimate capacity—thisrepresentsacurrentwhichitis
IEC61230Ed. 2, 2008, Portable Equipment for Earthing or
calculated the component is capable of conducting for the
Earthing and Short-Circuiting
specified time. It is expected that component damage may
2.5 IEEE Standard:
result. The component shall not be reused, except in test
IEEE386Standard for Separable Insulated Connector Sys-
situations.
tems for Power Distribution Systems Above 600V
3.1.6 withstand rating—this represents a near symmetrical
IEEE1048Guide for Protective Grounding of Power Lines
currentwhichshallbeconductedwithoutanycomponentbeing
IEEE1246Guide for Temporary Protective Grounding Sys-
damaged sufficiently to prevent being operable and reusable.
tems Used in Substations
Theprotectivegroundshallbecapableofpassingasecondtest
at this current after being cooled to ambient temperature.
3. Terminology
3.1 Definitions of Terms Specific to This Standard: CLAMPS FOR TEMPORARY PROTECTIVE
GROUNDS
3.1.1 continuous current rating—designated RMS current
which can be carried continuously under specified conditions.
4. Scope
3.1.2 protective ground assembly—a temporary electrical
4.1 This specification covers clamps used with ferrules and
connection between a source of potential energization and the
elastomer or thermoplastic covered flexible cable in the manu-
earth, rated for the maximum anticipated fault current or
facture of protective grounds installed temporarily for protec-
continuous induced current, or both.
tive grounding of de-energized circuits.
3.1.2.1 Discussion—Throughout this specification, kc
mil=1000 circular mils.
5. Classification
5.1 Clamps are furnished in, but not limited to, three types
Available from American National Standards Institute, 11 West 42nd St., 13th
according to their function and method of installation, as
Floor, New York, NY 10036.
5 follows:
AvailablefromInsulatedCableEngineersAssoc.,P.O.BoxP,SouthYarmouth,
5.1.1 Type I—Clamps for installation on de-energized con-
MA 02664.
Available from International Electrotechnical Commission (IEC), 3 rue de
ductors equipped with eyes for installation with removable hot
Varembé, Case postale 131, CH-1211, Geneva 20, Switzerland, http://www.iec.ch.
sticks.
5.1.2 Type II—Clamps for installation on de-energized con-
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org. ductors having permanently mounted hot sticks.
F855−14
TABLE 2 Ultimate Assembly Rating for High X/R Ratio Applications
High Asymmetrical Test Requirements
X/R =30
Rating
Test
Cycle Current Peak
Grade Rated 1 t
Duration
Values (kA)
Size Current (Mega amps -s)
(cycles)
Rating X 2.69
(kA)
1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th 15th
1H 15 41 37 34 32 30 28 27 26 25 25 24 24 23 23 23 15 74
2H 25 68 62 57 53 50 47 45 43 42 41 40 39 38 38 38 15 208
3H 31 84 76 70 65 61 58 56 53 52 50 49 48 47 47 46 15 312
4H 39 105 96 88 82 77 73 70 67 65 63 62 61 60 59 58 15 501
5H 47 127 116 106 99 93 88 84 81 78 76 74 73 72 71 70 15 728
6H 55 148 135 124 116 109 103 98 94 91 89 87 85 84 83 82 15 997
7H 68 183 167 154 143 134 127 121 117 113 110 107 105 104 102 101 15 1523
NOTE 1—The above current values are based on electromechanical test values.
NOTE 2—Assemblies that have been subjected to these shall not be re-used.
NOTE 3—For use with currents exceeding 20 % asymmetry factor.
NOTE 4—See X4.7.2 for additional information.
NOTE 5—Alternate testing circuits are available for laboratories that cannot achieve the above requirements. See Appendix X4 for details.
F855−14
5.1.3 Type III—Clamps for installation on permanently
Copper Base Alloy Aluminum Base Alloy
grounded conductors or metal structures with tee handles, and
Tensile strength, min 207 MPa (30 000 psi) 207 MPa (30 000 psi)
eyes or square or hexagon head screw(s), or both.
Yield strength, min 90 MPa (13 000 psi) 138 MPa (20 000 psi)
5.1.4 Othertypesofspecialclamps,suchasthoseforcluster
Elongation, min 6 % 3 %
grounds or for underground equipment grounding, may be
8.2 Type II clamps shall be equipped with an insulating
made, tested, and certified by the manufacturer as meeting the
handle (hot stick) appropriate for the nominal voltage of the
requirements of this specification.
circuit to be grounded.
5.1.5 Separable insulated connectors used in manufacturing
underground equipment grounding assemblies shall meet the
9. Electrical and Mechanical Properties
requirements of IEEE 386.
9.1 Electrical and mechanical properties shall conform to
5.2 Clampsarefurnishedingradesaccordingtomechanical
the requirements prescribed in Table 1 or Table 2,as
strengths, short circuit capabilities, and duration of faults, as
appropriate, and the following paragraphs. See Appendix X3
indicated in Table 1.
for a discussion and derivation of the current levels in Table 1.
5.3 Clamps are furnished in two classes according to the See Appendix X4 for a discussion of the effects of asymmetri-
characteristics of the main contact jaws: cal current and the derivation of the currents in Table 2.
5.3.1 Class A—Clamp jaws with smooth contact surfaces.
9.1.1 Types I and II stick installed clamps shall be designed
5.3.2 Class B—Clamp jaws with serrations, or cross
such that a failure does not increase the risk of injury to the
hatching, or other means intended to abrade or bite through user or have excess mechanical strength to prevent failure,
corrosion products on the surfaces of the conductor being
defined as follows:
clamped.
9.1.1.1 In the event the clamp is over-torqued during
installation, normal fracture shall be such that the attached
6. Sizes
cable remains under control by being retained with the stick.
9.1.1.2 Clamps with an ultimate torque strength exceeding
6.1 Clamp size is the combination of the main contact and
45N·m(400lbf·in.)areexemptfromtheprovisionsof9.1.1.1.
cable size ranges as listed by the manufacturers. It should be
noted that the main contact may connect to a cable or bus bar 9.1.2 Resistancefromthemaincontacttotheattachedcable
contact shall be less than that for an equal length of maximum
or be used at the “ground end” to connect to a variety of
conductive grounded objects. size cable(s) for which the clamp is rated.
9.1.3 Maincontactsshallacceptandclampallconductorsor
7. Ordering Information structural members in accordance with the manufacturer’s
rating.
7.1 Orders for clamps under this specification shall include
9.1.4 Clamp shall accept hand assembly of all cables fitted
this ASTM designation and the following information:
with compatible ferrules as rated per Table 3.
7.1.1 Quantity,
9.1.5 Cable termination shall include a cable support or
7.1.2 Name (grounding clamp),
shallbemadetoacceptacablesupportingferrule.Thissupport
7.1.3 Main contact size ranges, conductor descriptions, and
shall secure the entire cable over the jacket and is provided in
materials which are to be clamped by main contact,
addition to the electrical connection to the strand.
7.1.4 Cable size, material, and description by which clamps
9.1.6 Type I clamps shall be operable with clamp sticks and
are to be assembled,
shall fit securely inside a nominal 13 mm ( ⁄2 in.) wide slot in
7.1.5 Type (see 5.1),
the head of the stick.
7.1.6 Grade (see 5.2 and Table 1 or Table 2),
7.1.7 Class (see 5.3),
10. Workmanship, Finish, and Appearance
7.1.8 Asymmetrical current or other supplementary
requirements, if applicable. (See Supplementary Requirements
10.1 Components shall be free of structural porosity, fins,
S1 to S10 for styles and designs.)
sharp edges, splits, cracks, and other defects that affect
handling or performance.
NOTE 2—A typical ordering description is as follows: 100 Grounding
Clamps, Main contact range #2 to 350 kcmil for 2/0 Copper flexible
10.2 All parts shall be formed, machined, and assembled
grounding cable,ASTM F855, Type 1, Grade 3, ClassA, Design C, Style
with sufficient accuracy for smooth operation by hand, and
7.
shallbefreeofexcessiveloosenesstotheextentdetrimentalto
NOTE 3—It is expected that manufacturers will publish catalog data
repeated applications at the recommended installing torque.
conforming to this specification that will combine the
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F855 − 09 F855 − 14
Standard Specifications for
Temporary Protective Grounds to Be Used on De-energized
Electric Power Lines and Equipment
This standard is issued under the fixed designation F855; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These specifications cover the equipment making up the temporary grounding system used on de-energized electric power
lines, electric supply stations, and equipment.
1.2 It is common practice for the users of protective grounding equipment to prepare complete instructions and regulations to
govern in detail the correct use and maintenance of such equipment.
1.3 The uses and maintenance of this equipment are beyond the scope of these specifications.
1.4 These specifications for a system of protective grounding utilizing copper cables are covered in four parts, as follows:
Sections
Clamps for Temporary Protective Grounds 4 – 16
Ferrules for Temporary Protective Grounds 17 – 30
Cables for Temporary Protective Grounds 31 – 39
Protective Grounds (Complete Assembly With Clamps, Ferrules, 40 – 52
and Cable)
1.5 Each of the four parts is an entity of itself, but is listed as a part of the system for completeness and clarification.
1.6 Currents presented in Table 1 are based upon cable melting times, as determined from equations by I. M. Onderdonk and
are to used in situations involving an asymmetry value less than 20 % (X/R ≤ 1.8). See Appendix X3.
1.6.1 Currents presented in Table 2 are based upon the values from EPRI Project RP2446 Computer Program RTGC “A Desktop
Computer Program for Calculating Rating of Temporary Grounding Cables” and are to be used in situations involving an
asymmetry value greater then 20 % (X/R ^ 1.8), see Appendix X4.
NOTE 1—Table 1 represents the clamp and assembly ratings that existed prior to this revision. Table 2 represents new ratings now required for high
X/R situations.
1.6.2 See Appendix X3 and Appendix X4 for a discussion of these topics.
1.7 The values stated in Newton-Meter units are to be regarded as the standard. The values in parentheses are the inch-pound
units.
1.8 The following precautionary caveat pertains to the test method portions, Sections 12 and 25 of these specifications:This
standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior
to use.
2. Referenced Documents
2.1 ASTM Standards:
B172 Specification for Rope-Lay-Stranded Copper Conductors Having Bunch-Stranded Members, for Electrical Conductors
B173 Specification for Rope-Lay-Stranded Copper Conductors Having Concentric-Stranded Members, for Electrical Conduc-
tors
These specifications are under the jurisdiction of ASTM Committee F18 on Electrical Protective Equipment for Workers and are the direct responsibility of Subcommittee
F18.45 on Mechanical Apparatus.
Current edition approved May 1, 2009Oct. 1, 2014. Published July 2009November 2014. Originally approved in 1983. Last previous edition approved in 20042009 as
F855 – 04.F855 – 09. DOI: 10.1520/F0855-09.10.1520/F0855-14.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F855 − 14
TABLE 1 Protective Ground Cable, Ferrule, Clamp and Assembly Ratings for Symmetrical Current
Grounding Clamp Torque
A
Short Circuit Properties
Strength, min
CD
Withstand Rating, Symmetrical Continuous
Ultimate Rating Capacity , Symmetrical
B
Yield Ultimate kA kA Current
RMS, 60 Hz
Grade RMS, 60 Hz Rating, A
RMS, 60
15 30
15 30 cycles 60 Maximum
Hz
Copper Cable cycles cycles
lbf·in. n·m lbf·in. n·m cycles (500 cycles Copper Test
Size (250 (500
(250 ms) ms) (1 s) Cable Size
ms) ms)
1 280 32 330 37 14 10 #2 18 13 9 2/0 200
2 280 32 330 37 21 15 1/0 29 21 14 4/0 250
3 280 32 330 37 27 20 2/0 37 26 18 4/0 300
4 330 37 400 45 34 25 3/0 47 33 23 250 kcmil 350
5 330 37 400 45 43 30 4/0 59 42 29 250 kcmil 400
6 330 37 400 45 54 39 250 kcmil or 70 49 35 350 kcmil 450
2 2/0
7 330 37 400 45 74 54 350 kcmil or 98 69 48 550 kcmil 550
2 4/0
A
Withstand and ultimate short circuit properties are based on performance with surges not exceeding 20 % asymmetry factor (see 9.1 and 12.3.4.2).
B
Yield shall mean no permanent deformation such that the clamp cannot be reused throughout its entire range of application.
C
Ultimate rating represents a symmetrical current which the assembly or individual components shall carry for the specified time.
D
Ultimate values are based upon application of Onderdonk’s equation to 98 % of nominal circular mil area allowed by Specifications B172 and B173.
D470 Test Methods for Crosslinked Insulations and Jackets for Wire and Cable
D753 Specification for General Purpose Polychloroprene Jacket for Wire and Cable (Withdrawn 1984)
D2219 Specification for Poly(Vinyl Chloride) Insulation for Wire and Cable, 60°C Operation
D2633 Test Methods for Thermoplastic Insulations and Jackets for Wire and Cable
D2768 Specification for General-Purpose Ethylene-Propylene Rubber Jacket for Wire and Cable (Withdrawn 2007)
D2770 Specification for Ozone-Resisting Ethylene-Propylene Rubber Integral Insulation and Jacket for Wire and Cable
(Withdrawn 2007)
E8/E8M Test Methods for Tension Testing of Metallic Materials
2.2 ANSI Standard:
C 37.09 Standard Test Procedure for AC High-Voltage Circuit Breakers Rated on a Symmetrical Basis
2.3 ICEA/NEMA Standard:
ICEA S-19-81/NEMA WC 3-80 (R 1986) Rubber Insulated Wire and Cable for the Transmission and Distribution of Electrical
Energy
2.4 IEC Standard:
IEC 61230 Ed. 2, 2008, Portable Equipment for Earthing or Earthing and Short-Circuiting
2.5 IEEE Standard:
IEEE 386 Standard for Separable Insulated Connector Systems for Power Distribution Systems Above 600V
IEEE 1048 Guide for Protective Grounding of Power Lines
IEEE 1246 Guide for Temporary Protective Grounding Systems Used in Substations
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 continuous current rating—designated RMS current which can be carried continuously under specified conditions.
3.1.2 protective ground assembly—a temporary electrical connection between a source of potential energization and the earth,
rated for the maximum anticipated fault current or continuous induced current, or both.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American National Standards Institute, 11 West 42nd St., 13th Floor, New York, NY 10036.
Available from Insulated Cable Engineers Assoc., P.O. Box P, South Yarmouth, MA 02664.
Available from International Electrotechnical Commission (IEC), 3 rue de Varembé, Case postale 131, CH-1211, Geneva 20, Switzerland, http://www.iec.ch.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.
3.1.2.1 Discussion—
Throughout this specification, kc mil = 1000 circular mils.
3.1.3 protective grounding equipment—devices installed temporarily on de-energized electric power circuits for the purposes of
potential equalization and to conduct a short circuit current for a specified duration (time).
F855 − 14
TABLE 2 Ultimate Assembly Rating for High X/R Ratio Applications
High Asymmetrical Test Requirements
Rating X/R = 30
Last Cycle
Rated 1st Cycle Current Peak Test
Grade Size Current Peak
Current (kA) Duration (cycles)
(kA)
(kA) X 2.69
1H No. 2 15 41 23 15
2H 1/0 25 65 37 15
3H 2/0 31 84 46 15
4H 3/0 39 105 58 15
5H 4/0 47 126 70 15
6H 250 MCM 55 148 82 15
7H 350 MCM 68 183 101 15
TABLE 2 Ultimate Assembly Rating for High X/R Ratio Applications
High Asymmetrical Test Requirements
X/R = 30
Rating
Test
Cycle Current Peak
Grade Rated 1 t
Duration
Values (kA)
Size Current (Mega amps -s)
(cycles)
Rating X 2.69
(kA)
1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th 15th
1H 15 41 37 34 32 30 28 27 26 25 25 24 24 23 23 23 15 74
2H 25 68 62 57 53 50 47 45 43 42 41 40 39 38 38 38 15 208
3H 31 84 76 70 65 61 58 56 53 52 50 49 48 47 47 46 15 312
4H 39 105 96 88 82 77 73 70 67 65 63 62 61 60 59 58 15 501
5H 47 127 116 106 99 93 88 84 81 78 76 74 73 72 71 70 15 728
6H 55 148 135 124 116 109 103 98 94 91 89 87 85 84 83 82 15 997
7H 68 183 167 154 143 134 127 121 117 113 110 107 105 104 102 101 15 1523
F855 − 14
NOTE 1—The above current values are based on electromechanical test values.
F855 − 14
NOTE 2—Assemblies that have been subjected to these shall not be re-used.
F855 − 14
NOTE 3—For use with currents exceeding 20 % asymmetry factor.
F855 − 14
NOTE 4—See X4.7.2 for additional information.
F855 − 14
NOTE 5—Alternate testing circuits are available for laboratories that cannot achieve the above requirements. See Appendix X4 for details.
F855 − 14
3.1.4 time to failure—failure time of the cable is the time between the initiation of current flow and the instant at which arcing
begins.
3.1.5 ultimate capacity—this represents a current which it is calculated the component is capable of conducting for the specified
time. It is expected that component damage may result. The component shall not be reused, except in test situations.
3.1.6 withstand rating—this represents a near symmetrical current which shall be conducted without any component being
damaged sufficiently to prevent being operable and reusable. The protective ground shall be capable of passing a second test at
this current after being cooled to ambient temperature.
CLAMPS FOR TEMPORARY PROTECTIVE GROUNDS
4. Scope
4.1 This specification covers clamps used with ferrules and elastomer or thermoplastic covered flexible cable in the manufacture
of protective grounds installed temporarily for protective grounding of de-energized circuits.
5. Classification
5.1 Clamps are furnished in, but not limited to, three types according to their function and method of installation, as follows:
5.1.1 Type I—Clamps for installation on de-energized conductors equipped with eyes for installation with removable hot sticks.
5.1.2 Type II—Clamps for installation on de-energized conductors having permanently mounted hot sticks.
5.1.3 Type III—Clamps for installation on permanently grounded conductors or metal structures with tee handles, and eyes or
square or hexagon head screw(s), or both.
5.1.4 Other types of special clamps, such as those for cluster grounds or for underground equipment grounding, may be made,
tested, and certified by the manufacturer as meeting the requirements of this specification.
5.1.5 Separable insulated connectors used in manufacturing underground equipment grounding assemblies shall meet the
requirements of IEEE 386.
5.2 Clamps are furnished in grades according to mechanical strengths, short circuit capabilities, and duration of faults, as
indicated in Table 1.
5.3 Clamps are furnished in two classes according to the characteristics of the main contact jaws:
5.3.1 Class A—Clamp jaws with smooth contact surfaces.
5.3.2 Class B—Clamp jaws with serrations, or cross hatching, or other means intended to abrade or bite through corrosion
products on the surfaces of the conductor being clamped.
6. Sizes
6.1 Clamp size is the combination of the main contact and cable size ranges as listed by the manufacturers. It should be noted
that the main contact may connect to a cable or bus bar or be used at the “ground end” to connect to a variety of conductive
grounded objects.
7. Ordering Information
7.1 Orders for clamps under this specification shall include this 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, and materials which are to be clamped by main contact,
7.1.4 Cable size, material, and description by which clamps are 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 supplementary requirements, if applicable. (See Supplementary Requirements S1 to S10
for styles and designs.)
NOTE 2—A typical ordering description is as follows: 100 Grounding Clamps, Main contact range #2 to 350 kcmil for 2/0 Copper flexible grounding
cable, ASTM F855, Type 1, Grade 3, Class A, Design C, Style 7.
NOTE 3—It is expected that manufacturers will publish catalog data conforming to this specification that will combine the requirements of 7.1.1 – 7.1.8
in a single product number. With that system, a typical order description is: 100 (Smith Manufacturing Co. Product No. XXXX) grounding clamps ASTM
F855, Grade 2 or 2H.
8. Materials
8.1 Current carrying parts made of copper base or aluminum base alloy shall have the following material properties in
accordance with Test Methods E8/E8M:
F855 − 14
Copper Base Alloy Aluminum Base Alloy
Tensile 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)
Elongation, min 6 % 3 %
8.2 Type II clamps shall be equipped with an insulating handle (hot stick) appropriate for the nominal voltage of the circuit to
be grounded.
9. Electrical and Mechanical Properties
9.1 Electrical and mechanical properties shall conform to the requirements prescribed in Table 1 or Table 2, as appropriate, and
the following paragraphs. See Appendix X3 for a discussion and derivation of the current levels in Table 1. See Appendix X4 for
a discussion of the effects of asymmetrical current and the derivation of the currents in
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