ASTM F2249-03(2015)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F2249 −03 (Reapproved 2015)
Standard Specification for
In-Service Test Methods for Temporary Grounding Jumper
Assemblies Used on De-Energized Electric Power Lines and
Equipment
This standard is issued under the fixed designation F2249; 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 2.2 IEEE Standards:
IEEE Standard 80–1986 IEEE Guide for Safety in AC
1.1 These specifications cover the in-service inspection and
Substation Grounding
electrical testing of temporary protective grounding jumper
IEEE Standard 1048–1990 IEEE Guide for the Protective
assemblies which have been used by electrical workers in the
Grounding of Power Lines
field.
1.2 Thesespecificationsdiscussmethodsfortestingground- 3. Terminology
ing jumper assemblies, which consist of the flexible cables,
3.1 Definitions of Terms Specific to This Standard:
ferrules, clamps and connectors used in the temporary protec-
3.1.1 grounding jumper assembly—grounding cable with
tive grounding of de-energized circuits.
connectors and ground clamps attached, also called a ground-
1.3 Manufacturing specifications for these grounding ing jumper or a protective ground assembly installed tempo-
jumper assemblies are in Specifications F855. rarilyonde-energizedelectricpowercircuitsforthepurposeof
potential equalization and to conduct a short circuit current for
1.4 The application, care, use, and maintenance of this
a specified duration (time).
equipment are beyond the scope of this specification.
1.5 Units of measurement used in this specification are in 4. Significance and Use
the Metric system (SI) with English units given in parentheses.
4.1 Grounding jumper assemblies can be damaged by rough
1.6 The following safety hazards caveat pertains only to the
handling, long term usage, weathering, corrosion, or a combi-
test portions of this specification. This standard does not nation thereof. This deterioration may be both physical and
purport to address all of the safety concerns, if any, associated
electrical.
with its use. It is the responsibility of the user of this standard
4.2 The test procedures in this specification provide an
to establish appropriate safety and health practices and
objective means of determining if a grounding jumper assem-
determine the applicability of regulatory requirements prior to
bly meets minimum electrical specifications. These methods
use.
permit testing of grounding jumper assemblies under con-
trolled conditions.
2. Referenced Documents
4.3 Each responsible entity must determine the required
2.1 ASTM Standards:
safety margin for their workers during electrical fault condi-
B193 Test Method for Resistivity of Electrical Conductor
tions. Guidelines for use in the determination of these condi-
Materials
tions are beyond the scope of this specification and can be
F855 SpecificationsforTemporaryProtectiveGroundstoBe
found in such standards as IEEE Standard 80–1986 and IEEE
Used on De-energized Electric Power Lines and Equip-
Standard 1048–1990.
ment
4.4 Mechanical damage, other than broken strands, may not
significantly affect the cable resistance. Close manual and
This specification is under the jurisdiction of ASTM Committee F18 on
visual inspection is required to detect some types of mechani-
Electrical Protective Equipment for Workers and is the direct responsibility of
Subcommittee F18.45 on Mechanical Apparatus.
cal damage.
CurrenteditionapprovedMay1,2015.PublishedJuly2015.Originallyapproved
4.5 The test procedures in this specification should be
in 2003. Last previous edition approved in 2009 as F2249-03(2009). DOI:
10.1520/F2249-03R15.
performed at a time interval established by the user to ensure
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 AvailablefromtheInstituteofElectricalandElectronicsEngineers,Inc.(IEEE)
the ASTM website. 1828 L St., NW, Suite 1202, Washington, CD 20036–5104.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2249−03 (2015)
that defective grounding jumper assemblies are detected and 7.5 In-Service Electrical Resistance Pass/Fail Criteria
removed from service in a timely manner. —The pass/fail criterion of a grounding jumper assembly is
based on the resistance value of the assembly (cable, ferrules
4.6 Retest the grounding jumper assembly after performing
and clamps) which is higher than the established resistance
any maintenance, in order to ensure its integrity.
value for new assemblies. This increase in resistance accounts
for the expected normal deterioration of the assembly due to
5. Inspection of Grounding Jumper Assemblies
aging, contamination and corrosion, particularly in the contact
5.1 Visual inspection shall be made of all grounding jumper
areas of the cable ferrules and clamps. The allowable increase
assemblies prior to testing.
in resistance is such as to permit the grounding jumper
5.1.1 If the following defects are evident, the grounding
assembly to perform safely during electrical faults. The
jumpers may be rejected without electrical testing:
grounding jumper assembly, when subjected to its rated maxi-
5.1.1.1 Cracked or broken ferrules and clamps,
mum fault current and duration, must withstand the fault
5.1.1.2 Exposed broken strands,
without its components separating, but some heat damage and
5.1.1.3 Cut or badly mashed or flattened cable,
discoloration is acceptable. The electrical resistance value for
5.1.1.4 Extensively damaged cable- covering material,
thepass/failcriterionismadeupoftwoparts(Fig.1),thecable
5.1.1.5 Swollen cable jacket or soft spots, indicating inter-
resistance and the resistance of the two ends containing short
nal corrosion, and
cable sections, ferrules and clamps. When the grounding
5.1.1.6 Cable strands with a black deposit on them.
jumperassembliesaretestedwithadcsource,thedcresistance
5.1.2 Grounding jumper assemblies which are visually de-
of the assembly is used for the pass or fail purposes. With an
fective shall be removed from service and permanently
ac source, the impedance of the cable and the impedance of the
marked, tagged or destroyed (if beyond repair) to prevent
ends (ferrules and clamps) are used to determine if the
re-use.
grounding jumper fails or passes the test.
5.1.3 Before the grounding jumper assembly can be placed
back in service, it must pass the inspection requirements in
A
TABLE 1 Copper Cable Resistance, mΩ
5.1.1, and the electrical requirements in Section 7.
Grounding Resistance, mΩ/ft Resistance, mΩ/ft Resistance, mΩ/ft
5.1.4 All physical connections should be checked for tight-
Cable Size at 5°C (41°F) at 20°C (68°F) at 35°C (95°F)
ness with specified torque values.
#2 0.1471 0.1563 0.1655
1/0 0.0924 0.0983 0.1040
6. Cleaning and Measuring of Grounding Jumper
2/0 0.0733 0.0779 0.0825
4/0 0.0461 0.0490 0.0519
Assembly Prior to Electrical Testing
A
Values are calculated from data in Test Method B193.
6.1 Identify the cable gage (AWG) and a make a precise
measurement of the cable length. See Fig. 1.
6.2 Thoroughly clean the jaws of the clamps with a stiff
7.5.1 Cable Resistance—Table 1 provides resistance values
wire brush.
for various sizes of cables used in grounding jumper assem-
6.3 Attach the grounding jumper assembly clamps firmly to
blies. The cable resistance can change with ambient tempera-
the test set.
tures. A 69°F change in ambient temperatures will cause a
62 % change in the measurement of resistance values. Table 1
7. Electrical Requirements
gives cable resistance values for a practical range of tempera-
7.1 The user must select the test method with the desired tures (41, 68, and 95°F). Results from theASTM Round Robin
precision and repeatability. The test instrument should be Tests have shown that an increase in cable resistance at a given
sufficiently accurate to detect at least a one foot or less change
temperature due to aging effects should not exceed 5 %.
in cable length to ensure that the cable meets requirements. Therefore, the maximum acceptable resistance in cables used
in temporary protective grounding jumpers should be equal or
7.2 Each method must take into account a precise cable
less than 1.05 RL, when R = cable resistance from Table 1, and
resistance per foot and the length of the cable being tested.
L = cable length in feet.
7.3 Electrical tests relative to this standard are:
7.5.2 Resistance and Impedance of Copper Grounding
7.3.1 DC resistance measurements,
Jumper Assemblies—See Table 1.
7.3.2 AC impedance measurements, and
7.5.2.1 Maximum Resistance of the Grounding Jumper As-
7.3.3 Temperature rise measurements (supplementary
sembly (Rm):
method).
Rm 5 1.05 RL12Y (1)
7.4 DC Resistance or AC Impedance Method—Equipment
7.5.2.2 Maximum Impedance of the Grounding Jumper
required includes:
Assembly (Zm):
7.4.1 A minimum 10 A dc source controllable to 5 % of
output current, short circuit protected, or
2 2
Zm 5 =~1.05RL12Y! 1~XL! (2)
7.4.2 A minimum 10 A ac source controllable to 5 % of
where:
output current, short circuit protected.
7.4.3 Measuring method for measurements of cable length X = reactance of the cable in mΩ.
calibrated in inches or centimetres. NOTE 1—Values of X can be found in data books such as the Standard
F2249−03 (2015)
Robin III (See Appendix X1). The resistance of Y in the Rm
(Eq1)hasbeendeterminedbyconservativeanalysisofthedata
tobe0.16mΩ.Thisvalueisbelowthe“fusingrange”ofcables
that passed the fault tests. The value of Y = 0.16 mΩ or 2 Y =
0.32 mΩ for all cable sizes. Therefore, the pass/fail resistance
value is:
FIG. 1Resistance and Impedance of Copper Grounding Jumper
Rm 5 1.05 RL10.32 mΩ (3)
Assemblies
NOTE 2—Table 2 was derived from Eq 3.
7.5.4 Testing With an AC Source—When an ac source is
Y = resistance of clamps, ferrule and portions of the cable
used, it will determine the grounding jumper assembly imped-
inside the ferrule, mΩ
ance (Z). This impedance is a function of the cable and the test
L = cable length expressed in feet (ferrule to ferrule mea-
surement to the nearest inch, not including shrouded electrode spacing. For cable spacing of 12 in. or less, the cable
reactance can be very low and the impedance value can
portion of some ferrules which cover the cable
insulation), and approach that of the cable resistance. The impedance (Z)
R = cable resistance from Table 1,mΩ. obtained from such a measurement should be compared with
the calculated limiting maximum impedance (Zm) using Eq 2
to determine if the grounding jumper assembly has passed or
failed the test. The pass/fail impedance value based on 2/0
Handbook of Electrical Engineers.
cable fault tests is:
7.5.3 Testing with a DC Source—Adc source can be used to
2 2
=
Zm 5 ~1.05RL10.32! 1~XL! (4)
determine the pass/fail value for a given grounding jumper
assembly. The resistance value (R) obtained from such a
If multiple spacings of the cable are utilized in the test setup,
measurement should be compared with the calculated limiting
the above equation becomes:
maximum resistance (Rm) using Eq 1 or it can be compared to
2 2
the resistance values in Table 2. The calculated criterion for
Zm 5 = 1.05RL10.32 1 X L 1X L …1X L (5)
~ ! ~ !
1 1 2 2 N N
pass/fail is based on 2/0 cable fault tests conducted in Round NOTE3—ACtestingmeasurementsofgroundingjumperassembliesare
susceptible to errors and inconsistent results due to induction in the cable
if the cable is not laid out per the test method instructions. Different
instruments require different configurations (see Fig. 2).
Standard Handbook for Electrical Engineers—Thirteenth Edition by Fink &
NOTE4—ACtestingmeasurementsofgroundingjumperassembliesare
Beaty, McGraw-Hill Book Co., New York, NY.
TABLE 2 Pass/Fail Resistance Values for Copper Grounding Jumper Assemblies
Rmax Limits—DC Resistance, mΩ
#2 Cable 1/0 Cable 2/0 Cable 4/0 Cable
Cable Length,
ft
5°C (41°F) 20°C (68°F)35°C (95°F) 5°C (41°F) 20°C (68°F)35°C (95°F) 5°C (41°F) 20°C (68°F)35°C (95°F) 5°C (41°F) 20°C (68°F)35°C (95°F)
A
0.25 0.039 0.041 0.043 0.024 0.026 0.027 0.019 0.020 0.022 0.012 0.013 0.014
A
0.5 0.077 0.082 0.087 0.049 0.052 0.055 0.038 0.041 0.043 0.024 0.026 0.027
A
0.75 0.116 0.123 0.130 0.073 0.077 0.082 0.058 0.061 0.065 0.036 0.039 0.041
1 0.474 0.484 0.494 0.417 0.423 0.429 0.397 0.402 0.407 0.368 0.371 0.374
2 0.629 0.648 0.668 0.514 0.526 0.538 0.474 0.484 0.493 0.417 0.423 0.429
3 0.783 0.812 0.841 0.611 0.630 0.648 0.551 0.565 0.580 0.465 0.474 0.483
4 0.938 0.976 1.015 0.708 0.733 0.757 0.628 0.647 0.667 0.514 0.526 0.538
5 1.092 1.141 1.189 0.805 0.836 0.866 0.705 0.729 0.753 0.562 0.577 0.592
6 1.247 1.305 1.363 0.902 0.939 0.975 0.782 0.811 0.840 0.610 0.629 0.647
7 1.401 1.469 1.536 0.999 1.043 1.084 0.859 0.893 0.926 0.659 0.680 0.701
8 1.556 1.633 1.710 1.096 1.146 1.194 0.936 0.974 1.013 0.707 0.732 0.756
9 1.710 1.797 1.884 1.193 1.249 1.303 1.013 1.056 1.100 0.756 0.783 0.810
10 1.865 1.961 2.058 1.290 1.352 1.412 1.090 1.138 1.186 0.804 0.835 0.865
11 2.019 2.125 2.232 1.387 1.455 1.521 1.167 1.220 1.273 0.852 0.886 0.919
12 2.173 2.289 2.405 1.484 1.559 1.630 1.244 1.302 1.360 0.901 0.937 0.974
13 2.328 2.453 2.579 1.581 1.662 1.740 1.321 1.383 1.446 0.949 0.989 1.028
14 2.482 2.618 2.753 1.678 1.765 1.849 1.398 1.465 1.533 0.998 1.040 1.083
15 2.637 2.782 2.927 1.775 1.868 1.958 1.474 1.547 1.619 1.046 1.092 1.137
16 2.791 2.946 3.100 1.872 1.971 2.067 1.551 1.629 1.706 1.094 1.143 1.192
17 2.946 3.110 3.274 1.969 2.075 2.176 1.628 1.711 1.793 1.143 1.195 1.246
18 3.100 3.274 3.448 2.066 2.178 2.286 1.705 1.792 1.879 1.191 1.246 1.301
19 3.255 3.438 3.622 2.163 2.281 2.395 1.782 1.874 1.966 1.240 1.298 1.355
20 3.409 3.602 3.796 2.260 2.384 2.504 1.859 1.956 2.053 1.288 1.349 1.410
25 4.181 4.423 4.664 2.746 2.900 3.050 2.244 2.365 2.486 1.530 1.606 1.682
30 4.954 5.243 5.533 3.231 3.416 3.596 2.629 2.774 2.919 1.772 1.864 1.955
35 5.726 6.064 6.402 3.716 3.933 4.142 3.014 3.183 3.352 2.014 2.121 2.227
40 6.498 6.885 7.271 4.201 4.449 4.688 3.399 3.592 3.785 2.256 2.378 2.500
45 7.270 7.705 8.140 4.686 4.965 5.234 3.783 4.001 4.218 2.498 2.635 2.772
50 8.043 8.526 9.009 5.171 5.481 5.780 4.168 4.410 4.651 2.740 2.893 3.045
A
This value may only be added to the full foot length measurements.
F2249−03 (2015)
NOTE 1—The cable configuration may h
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