ASTM F712-06(2018)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F712 −06 (Reapproved 2018)
Standard Test Methods and Specifications for
Electrically Insulating Plastic Guard Equipment for
Protection of Workers
ThisstandardisissuedunderthefixeddesignationF712;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 Thesetestmethodscoverthreeelectricaltestsonplastic
mine the applicability of regulatory limitations prior to use.
guards and assembled guard systems. They are:
1.6 The values stated in inch-pound units are to be regarded
1.1.1 Method A—Withstand voltage proof test,
as standard. The values given in parentheses are mathematical
1.1.2 Method B—Flashover voltage, and
conversions to SI units that are provided for information only
1.1.3 Method C—Leakage current.
and are not considered standard.
1.1.4 This specification covers plastic guard equipment and
1.7 This international standard was developed in accor-
guard systems used by workers for temporary insulation on
dance with internationally recognized principles on standard-
electric power circuits.
ization established in the Decision on Principles for the
1.1.5 Plastic guard equipment covered by this specification
Development of International Standards, Guides and Recom-
is rated for momentary, or brush contact only. Maximum-use
mendations issued by the World Trade Organization Technical
voltages are covered in Table 1 and Table 2.
Barriers to Trade (TBT) Committee.
1.2 These test methods cover, but are not limited to, the
following typical guards:
2. Referenced Documents
1.2.1 Conductor Guards and Connecting Covers as follows:
2.1 ASTM Standards:
1.2.1.1 Line guards,
D149Test Method for Dielectric Breakdown Voltage and
1.2.1.2 Line guard connectors,
DielectricStrengthofSolidElectricalInsulatingMaterials
1.2.1.3 Insulator covers,
at Commercial Power Frequencies
1.2.1.4 Dead-end covers,
D256Test Methods for Determining the Izod Pendulum
1.2.1.5 Bus guards, and
1.2.1.6 Bus “T” guards. Impact Resistance of Plastics
D570Test Method for Water Absorption of Plastics
1.2.2 Structure and Apparatus Covers as follows:
1.2.2.1 Pole guards,
2.2 IEEE Standard:
1.2.2.2 Ridge pin covers,
IEEE 978Guide for In-Service Maintenance and Electrical
1.2.2.3 Switch blade covers,
Testing for Live-Line Tools
1.2.2.4 Arm guards,
2.3 ANSI Standard:
1.2.2.5 Cutout covers,
C39.5Safety Requirements for Electrical and Electronic
1.2.2.6 Structural barriers, and
Measuring and Controlling Instrumentation
1.2.2.7 Cross arm guard.
2.4 UL Standard:
1.3 It is common practice for the user of this equipment to
94Tests for Flammability of Plastic Materials for Parts in
prepare instructions for the correct use and maintenance.
Devices and Appliances
1.4 The use and maintenance of this equipment is beyond
the scope of these test methods.
1.5 This standard does not purport to address all of the 2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
safety concerns, if any, associated with its use. It is the 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.
1 3
These test methods are under the jurisdiction of ASTM Committee F18 on Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
Electrical Protective Equipment for Workers and are the direct responsibility of 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.
Subcommittee F18.25 on Insulating Cover-Up Equipment. Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Current edition approved April 15, 2018. Published April 2018. Originally 4th Floor, New York, NY 10036, http://www.ansi.org.
approved in 1981. Last previous edition approved in 2011 as F712–06 (2011). Available from Underwriters Laboratories (UL), 333 Pfingsten Rd.,
DOI: 10.1520/F0712-06R18. Northbrook, IL 60062-2096, http://www.ul.com.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F712−06 (2018)
A
TABLE 1 Withstand Voltage Proof Test NOTE1—RubberinsulatingequipmentisrealisticallylimitedtoClass4
materialinthedesignspecificationstandards.Plasticguardequipmenthas
Class Rating, Max Use Proof Test Withstand Voltage
been designed to go beyond these voltages and provide a satisfactory
kV 60 Hz (in-service testing)
Criteria
degree of worker protection. Major differences exist in use criteria
Duration,
A
0-0 0-Ground 0-Ground kV
between the rubber and the plastic guard equipment. Each glove, sleeve,
min
60 Hz DC orotherarticleofrubberinsulatingequipmenthasagivensafetyfactorfor
the phase to phase voltage on which it may be used and the class or proof
2 14.6 8.4 13.0 18 1 No flashover
voltageatwhichitistested.Plasticguardequipment,however,isdesigned
other than
3 26.4 15.3 24.0 34 1
toprovideasatisfactorysafetyfactoronlywhenusedinaphase-to-ground
4 36.6 21.1 32.0 45 1 momentary
as a result of
5 48.3 27.0 42.0 60 0.5 exposure.Ifexposureisphase-to-phase,thenasatisfactorysafetyfactoris
6 72.5 41.8 64.0 91 0.25 too-close
only provided if the exposure is covered-phase-to-covered-phase.
spacing of
4.4 Work practices vary from user to user, dependent upon
electrode
A many factors. These may include, but are not limited to,
Cover-upmaterialsaretestedatvaluesgreaterthanthemaximumusephaseto
groundvalues.Themaximumusephasetophasevaluesrelatetoguardedphase
operating system voltages, construction design, work proce-
to guarded phase. The units are not rated for bare phase to guarded phase
dure techniques, weather conditions, etc. Therefore, except for
potentials.
the restrictions set forth in this specification because of design
limitations, the use and maintenance of this equipment is
A
beyond the scope of this specification.
TABLE 2 Minimum Flashover Test
Rating, Max Use Min Flashover Voltage
4.5 It is common practice and the responsibility of the user
kV 60 Hz Test φ-Ground kV
Criteria
of this type of protective equipment to prepare complete
A
0-0 0-Ground 60 Hz DC
instructions and regulations to govern in detail the correct and
2 14.6 8.4 14.0 20 No flashover
safe use of such equipment.
3 26.4 15.3 25.0 35 other than
4 36.6 21.1 34.0 48 momentary
5 48.3 27.0 43.0 61 as a result of
5. Apparatus
6 72.5 41.8 67.0 95 too-close
5.1 Voltage Source and Test Techniques—See Test Method
spacing of
electrode
D149. The test equipment shall have adequate power and
A
Cover-upmaterialsaretestedatvaluesgreaterthanthemaximumusephaseto
provide relatively stepless variable test voltage that can be
groundvalues.Themaximumusephasetophasevaluesrelatetoguardedphase
raised at a rate of approximately 1000V⁄s ac or 3000V⁄s dc.
to guarded phase. The units are not rated for bare phase to guarded phase
potentials.
5.2 Energized Inner Electrodes ,inaccordancewithTable3
and Table 4. The length should be sufficient to extend past the
ends of the guard or guard assemblies where appropriate.
3. Terminology
5.3 Outer Ground Electrode—A conductive material with
size and location as indicated in Table 3.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 insulating plastic guards—devices for temporary in-
5.4 Shielded Cable—To reduce the “room influence” when
stallation on structures or energized electric power circuits for
conducting ac leakage tests, the cable from the pickup elec-
electrical protection of personnel or equipment, or both.
trode to the current-measuring device should be a shielded
3.1.2 self extinguishing—relates to a property of a plastic cable with the cable shield grounded.
materialcompoundedsoastoceasecombustiononremovalof
6. Sampling
the source that caused ignition.
6.1 Design tests of each product model shall be conducted
4. Significance and Use
to verify that the requirements of Table 1 and Table 2 are met.
4.1 All three tests may be used for product design qualifi-
6.2 Design Tests—Samples shall consist of sufficient speci-
cation.
mens of each product used in a specific guard system to form
4.2 This specification covers the minimum electrical,
one of each assembly intended for field use.
chemical, and physical properties designated by the manufac-
6.2.1 The design tests will be used to qualify a specific
turer and the detailed procedures by which such properties are
product model and normally will not be repeated during
to be determined. The purchaser has the option to perform or
production.
have performed any of these tests and may reject equipment
6.2.2 Acceptance Tests— A test sample shall consist of one
that fails to meet the standard criteria. Claims concerning
or more specimens dependent on the percentage of the lot
failure to meet the specification are subject to verification by
being tested.
the manufacturer.
6.2.3 A lot is represented either by all the guards produced
in one production run or in one shipment.
4.3 Plastic guard equipment is used for protection against
6.2.4 Lots of new or unused guards shall have test speci-
accidentalbrushcontactbytheworker.Amarginofsafetyshall
mens selected at random.
be provided between the maximum voltage at which they are
used and the proof-test voltage at which they are tested. This
7. Classification
relationship is shown in Table 1 and Table 2.The equipment is
designed only for phase-to-ground or covered phase-to- 7.1 Guards are furnished in three types of materials speci-
covered-phase exposure. fied in Section 9 and explained as follows:
F712−06 (2018)
TABLE 3 Typical Electrodes for Testing Plastic Guard Equipment
A
Outer Ground Electrode
A
Type of Guards Energized Inner Electrode for All Tests
Proof Test Flashover and Leakage Tests
B
Line guards and line guard Round metal tube or bar. Complete electode shall be 4 by 6-in. flexible conductive pad
connectors spaced back from openings placed alternately on all exterior
Insulator covers and deadened Maximum conductor, hardware and insulator assembly for through which the energized surfaces and across conductor
C
covers which rated or similar mock-up including mandrel of electrode protrudes during the opening of guard and assembled
D
conductive material approximate. test only as necessary to avoid guard system joints spaced back
E C
Pole guards, ridge pin and Round metal tube, fabricated mandrel flashover. Therefore, the entire from openings through which the
D
switch blade covers or cluster small metal tubes. area of each cover shall be tested energized electrode protrudes
as nearly as practical. during the test only as necessary
D
Arm guards Round or rectangular metal tube or fabricated mandrel. to avoid flashover at outer ends.
C
Cutout covers Largest cutout with bare leads covered with equal rated
C
line hose. Or similar mock-up including mandrel of
D
conductive material.
Structural barrier Rectangular metal sheets approximately 3 mm (0.06 in.)
thick, having smoothly rounded edges and corners,
have been found to be satisfactory for this purpose.
Also satisfactory are wet felt or sponge-top electodes.
A
Moistened electrodes may be secured with rubber straps or blanket pins. Pressure-sensitive tape is helpful in securing dry metal foil electrodes.
B
Suitable materials include: metal foil or screen; tap water-moistened sponge sheeting, or blanket made of wool, or similar material including synthetics.
C
Thin metal sheet or screen wire secured on wood frames make suitable electrodes. Carved synthetic sponge moistened with tap water is suitable for small forms.
D
The dimensions of the mandrel are to approximate the maximum size of equipment to which the guard system is to be applied.
E
Metal canisters made for storing rubber blankets make suitable electrodes for pole guard tests.
TABLE 4 Inner Electrode Sizes
7.3 Guards are made in five classes in accordance with the
Rating—Max Use Inner Electrode Diameter, in. (mm) voltage ratings in Annex A1.
A
Class kV 60 Hz
Min Max
φ −φφ−Gr. 8. Ordering Information
2 14.6 8.4 0.25 (6.4) 0.75 (19.1)
8.1 Orders for guards under this specification shall include
3 26.4 15.3 0.25 (6.4) 0.75 (19.1)
the designation ASTM Specification F712 and should includ
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