ASTM F712-06(2011)
(Test Method)Standard Test Methods and Specifications for Electrically Insulating Plastic Guard Equipment for Protection of Workers
Standard Test Methods and Specifications for Electrically Insulating Plastic Guard Equipment for Protection of Workers
SIGNIFICANCE AND USE
All three tests may be used for product design qualification.
This specification covers the minimum electrical, chemical, and physical properties designated by the manufacturer and the detailed procedures by which such properties are to be determined. The purchaser has the option to perform or have performed any of these tests and may reject equipment that fails to meet the standard criteria. Claims concerning failure to meet the specification are subject to verification by the manufacturer.
Plastic guard equipment is used for protection against accidental brush contact by the worker. A margin of safety shall be provided between the maximum voltage at which they are used and the proof-test voltage at which they are tested. This relationship is shown in Table 1 and Table 2. The equipment is designed only for phase-to-ground or covered phase-to-covered-phase exposure.
Note 1—Rubber insulating equipment is realistically limited to Class 4 material in the design specification standards. Plastic guard equipment has been designed to go beyond these voltages and provide a satisfactory degree of worker protection. Major differences exist in use criteria between the rubber and the plastic guard equipment. Each glove, sleeve, or other article of rubber insulating equipment has a given safety factor for the phase to phase voltage on which it may be used and the class or proof voltage at which it is tested. Plastic guard equipment, however, is designed to provide a satisfactory safety factor only when used in a phase-to-ground exposure. If exposure is phase-to-phase, then a satisfactory safety factor is only provided if the exposure is covered-phase-to-covered-phase.
Work practices vary from user to user, dependent upon many factors. These may include, but are not limited to, operating system voltages, construction design, work procedure techniques, weather conditions, etc. Therefore, except for the restrictions set forth in this specification because of design limita...
SCOPE
1.1 These test methods cover three electrical tests on plastic guards and assembled guard systems. They are:
1.1.1 Method A—Withstand voltage proof test,
1.1.2 Method B—Flashover voltage, and
1.1.3 Method C—Leakage current.
1.1.4 This specification covers plastic guard equipment and guard systems used by workers for temporary insulation on electric power circuits.
1.1.5 Plastic guard equipment covered by this specification is rated for momentary, or brush contact only. Maximum-use voltages are covered in Table 1 and Table 2.
1.2 These test methods cover, but are not limited to, the following typical guards:
1.2.1 Conductor Guards and Connecting Covers as follows:
1.2.1.1 Line guards,
1.2.1.2 Line guard connectors,
1.2.1.3 Insulator covers,
1.2.1.4 Dead-end covers,
1.2.1.5 Bus guards, and
1.2.1.6 Bus “T” guards.
1.2.2 Structure and Apparatus Covers as follows:
1.2.2.1 Pole guards,
1.2.2.2 Ridge pin covers,
1.2.2.3 Switch blade covers,
1.2.2.4 Arm guards,
1.2.2.5 Cutout covers,
1.2.2.6 Structural barriers, and
1.2.2.7 Cross arm guard.
1.3 It is common practice for the user of this equipment to prepare instructions for the correct use and maintenance.
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 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.
1.6 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:F712 −06 (Reapproved 2011)
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 and health practices and determine the applica-
1.1 Thesetestmethodscoverthreeelectricaltestsonplastic
bility of regulatory limitations prior to use.
guards and assembled guard systems. They are:
1.6 Thevaluesstatedininch-poundunitsaretoberegarded
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
guard systems used by workers for temporary insulation on
2. Referenced Documents
electric power circuits.
1.1.5 Plastic guard equipment covered by this specification 2.1 ASTM Standards:
is rated for momentary, or brush contact only. Maximum-use D149Test Method for Dielectric Breakdown Voltage and
voltages are covered in Table 1 and Table 2. DielectricStrengthofSolidElectricalInsulatingMaterials
at Commercial Power Frequencies
1.2 These test methods cover, but are not limited to, the
D256Test Methods for Determining the Izod Pendulum
following typical guards:
Impact Resistance of Plastics
1.2.1 Conductor Guards and Connecting Covers as follows:
D570Test Method for Water Absorption of Plastics
1.2.1.1 Line guards,
2.2 IEEE Standard:
1.2.1.2 Line guard connectors,
1.2.1.3 Insulator covers, IEEE 978Guide for In-Service Maintenance and Electrical
Testing for Live-Line Tools
1.2.1.4 Dead-end covers,
1.2.1.5 Bus guards, and
2.3 ANSI Standard:
1.2.1.6 Bus “T” guards.
C39.5Safety Requirements for Electrical and Electronic
1.2.2 Structure and Apparatus Covers as follows:
Measuring and Controlling Instrumentation
1.2.2.1 Pole guards,
2.4 UL Standard:
1.2.2.2 Ridge pin covers,
94Tests for Flammability of Plastic Materials for Parts in
1.2.2.3 Switch blade covers,
Devices and Appliances
1.2.2.4 Arm guards,
1.2.2.5 Cutout covers,
3. Terminology
1.2.2.6 Structural barriers, and
3.1 Definitions of Terms Specific to This Standard:
1.2.2.7 Cross arm guard.
3.1.1 insulating plastic guards—devices for temporary in-
1.3 It is common practice for the user of this equipment to
stallation on structures or energized electric power circuits for
prepare instructions for the correct use and maintenance.
electrical protection of personnel or equipment, or both.
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 Nov. 15, 2011. Published November 2011. Originally 4th Floor, New York, NY 10036, http://www.ansi.org.
approved in 1981. Last previous edition approved in 2006 as F712–06. DOI: Available from Underwriters Laboratories (UL), 333 Pfingsten Rd.,
10.1520/F0712-06R11. 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 (2011)
A
TABLE 1 Withstand Voltage Proof Test voltageatwhichitistested.Plasticguardequipment,however,isdesigned
toprovideasatisfactorysafetyfactoronlywhenusedinaphase-to-ground
Class Rating, Max Use Proof Test Withstand Voltage
exposure.Ifexposureisphase-to-phase,thenasatisfactorysafetyfactoris
kV 60 Hz (in-service testing)
Criteria
only provided if the exposure is covered-phase-to-covered-phase.
Duration,
A
0-0 0-Ground 0-Ground kV
min
4.4 Work practices vary from user to user, dependent upon
60 Hz DC
many factors. These may include, but are not limited to,
2 14.6 8.4 13.0 18 1 No flashover
operating system voltages, construction design, work proce-
other than
3 26.4 15.3 24.0 34 1
4 36.6 21.1 32.0 45 1 momentary
dure techniques, weather conditions, etc.Therefore, except for
as a result of
5 48.3 27.0 42.0 60 0.5
the restrictions set forth in this specification because of design
6 72.5 41.8 64.0 91 0.25 too-close
limitations, the use and maintenance of this equipment is
spacing of
electrode
beyond the scope of this specification.
A
Cover-upmaterialsaretestedatvaluesgreaterthanthemaximumusephase
4.5 It is common practice and the responsibility of the user
to ground values. The maximum use phase to phase values relate to guarded
of this type of protective equipment to prepare complete
phasetoguardedphase.Theunitsarenotratedforbarephasetoguardedphase
potentials.
instructions and regulations to govern in detail the correct and
safe use of such equipment.
A
TABLE 2 Minimum Flashover Test
5. Apparatus
Rating, Max Use Min Flashover Voltage
kV 60 Hz Test φ-Ground kV 5.1 Voltage Source and Test Techniques—See Test Method
Criteria
A
0-0 0-Ground 60 Hz DC
D149. The test equipment shall have adequate power and
2 14.6 8.4 14.0 20 No flashover provide relatively stepless variable test voltage that can be
3 26.4 15.3 25.0 35 other than
raised at a rate of approximately 1000V/s ac or 3000V/s dc.
4 36.6 21.1 34.0 48 momentary
5 48.3 27.0 43.0 61 as a result of
5.2 Energized Inner Electrodes ,inaccordancewithTable3
6 72.5 41.8 67.0 95 too-close
and Table 4. The length should be sufficient to extend past the
spacing of
electrode ends of the guard or guard assemblies where appropriate.
A
Cover-upmaterialsaretestedatvaluesgreaterthanthemaximumusephase
5.3 Outer Ground Electrode—A conductive material with
to ground values. The maximum use phase to phase values relate to guarded
size and location as indicated in Table 3.
phasetoguardedphase.Theunitsarenotratedforbarephasetoguardedphase
potentials.
5.4 Shielded Cable—To reduce the “room influence” when
conducting ac leakage tests, the cable from the pickup elec-
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
the source that caused ignition.
6. Sampling
4. Significance and Use 6.1 Design tests of each product model shall be conducted
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-
cation. 6.2 Design Tests—Samples shall consist of sufficient speci-
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—Atest 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
4.3 Plastic guard equipment is used for protection against
in one production run or in one shipment.
accidentalbrushcontactbytheworker.Amarginofsafetyshall
6.2.4 Lots of new or unused guards shall have test speci-
be provided between the maximum voltage at which they are
mens selected at random.
used and the proof-test voltage at which they are tested. This
relationship is shown in Table 1 and Table 2.The equipment is
7. Classification
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:
NOTE1—RubberinsulatingequipmentisrealisticallylimitedtoClass4
materialinthedesignspecificationstandards.Plasticguardequipmenthas
7.1.1 Type I guards are constructed of plastic material
been designed to go beyond these voltages and provide a satisfactory
having mechanical impact properties suitable for cold weather
degree of worker protection. Major differences exist in use criteria
service.
between the rubber and the plastic guard equipment. Each glove, sleeve,
7.1.2 Type II guards have self-extinguishing plastic con-
orotherarticleofrubberinsulatingequipmenthasagivensafetyfactorfor
the phase to phase voltage on which it may be used and the class or proof struction.
F712−06 (2011)
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
8. Ordering Information
Rating—Max Use Inner Electrode Diameter, in. (mm)
8.1 Orders for guards under this specification shall include
A
Class kV 60 Hz
the designation ASTM Specification F712 and should include
Min Max
φ −φφ−Gr.
the following information.
2 14.6 8.4 0.25 (6.4) 0.75 (19.1)
8.1.1 Quantity,
3 26.4 15.3 0.25 (6.4) 0.75 (19.1)
4 36.6 21.1 0.25 (6.4) 0.75 (19.1)
8.1.2 Name-description of guard or cover,
5 48.3 27.0 0.50 (12.7) 1.50 (38.1)
8.1.3 Type, see 7.1.1 through 7.1.3,
6 72.5 41.8 0.75 (19.1) 2.00 (50.8)
8.1.4 Grade, see 7.2.1 through7.2.3,
A
Cover-upmaterialsaretestedatvaluesgreaterthanthemaximumusephase
to ground values. The maximum use phase to phase values relate to guarded
8.1.5 Class, see Table 1, Table 2,or Table 4,
phasetoguardedphase.Theunitsarenotratedforbarephasetoguardedphase
8.1.6 Size, if applicable, see Section 11.
potentials.
NOTE2—Atypicalorderingdescriptionisasfollows:100LineGuards,
ASTM Specification F712, Type I, Grade 1, Class 3A, 4.5-ft long.
NOTE 3—It is expected that manufacturers will publish catalog data
conforming to this specification that will combine the requirements of
8.1.2 and 8.1.6 in a single product number. With that system, a typical
7.1.3 Type III guards are constructed of self-extinguishing
order description is: 100 (Smith Manufacturing Co., Product No. XXXX)
plastic material having mechanical impact properties suitable
Line Guards, ASTM Specification F712.
for cold weather service.
9. Materials
7.2 Guards are furnished in three grades in accordance with
provisions for installation as follows:
9.1 Principal construction of insulating body shells shall be
in accordance with the material requirements as follows:
7.2.1 Grade 1 guards have hot stick handles attached for
installation. 9.1.1 Type I Guards—Minimum 1.5 ft·lbf/in. (80.06 J/m of
notch) notched izod impact strength at −20°F(−29°C); maxi-
7.2.2 Grade 2 guards are equipped with eyes for installation
mum water absorption 0.1 % by weight; minimum 380 V/mL
with removable hot sticks.
(0.025 mm) dielectric strength.
7.2.3 Grade3guardsareintendedforapplicationswherethe
9.1.2 Type II Guards—Minimum 1.0 ft·lbf/in. (53.4 J/m)
usual installation is by hand. These guards are equipped with
notched izod impact strength at −20°F (−29°C); maximum
rope loops, or their equivalent, so their removal may be
water absorption 0.5 % by weight; minimum 320V/mL(0.025
accomplished with hot sticks.
mm) dielectric strength; 94 V-O flame retardancy.
7.2.3.1 Example—Pole guards installed on a pole prior to
9.1.3 Type III Guards—Minimum3.0ft·lbf/in.(160.1J/mof
raising it close to overhead line conductors. After the pole is
notch) notched izod impact strength at −20°F(−29°C); maxi-
raised the guard is opened with hot sticks and allowed to slide
mum water absorption 0.09 % by weight; minimum 300V/mL
down the pole where it can be safely removed by hand.
(0.025
...
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