ASTM F712-88(1995)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 712 – 88 (Reapproved 1995)
Standard Test Methods for
Electrically Insulating Plastic Guard Equipment for
Protection of Workers
This standard is issued under the fixed designation F 712; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope Measuring and Controlling Instrumentation
1.1 These test methods cover three electrical tests on plastic
3. Significance and Use
guards and assembled guard systems. They are:
3.1 All three tests may be used for product design qualifi-
1.1.1 Method A—Withstand voltage proof test,
cation.
1.1.2 Method B—Flashover voltage, and
1.1.3 Method C—Leakage current.
4. Apparatus
1.2 These methods cover, but are not limited to, the follow-
4.1 Voltage Source and Test Techniques—See Test Method
ing typical guards:
D 149. The test equipment shall have adequate power and
1.2.1 Conductor Guards and Connecting Covers:
provide relatively stepless variable test voltage that can be
1.2.1.1 Line guards,
raised at a rate of approximately 1000 V/s ac or 3000 V/s dc.
1.2.1.2 Line guard connectors,
4.2 Energized Inner Electrodes, in accordance with Table 1
1.2.1.3 Insulator covers, and
and Table 2. The length should be sufficient to extend past the
1.2.1.4 Deadend covers.
ends of the guard or guard assemblies where appropriate.
1.2.2 Structure and Apparatus Covers:
4.3 Outer Ground Electrode—A conductive material with
1.2.2.1 Pole guards,
size and location as indicated in Table 1.
1.2.2.2 Ridge pin covers,
4.4 Shielded Cable— To reduce the “room influence” when
1.2.2.3 Switch blade covers,
conducting ac leakage tests, the cable from the pickup elec-
1.2.2.4 Arm guards,
trode to the current-measuring device should be a shielded
1.2.2.5 Cutout covers, and
cable with the cable shield grounded.
1.2.2.6 Structural barriers,
1.3 It is common practice for the user of this equipment to
5. Sampling
prepare instructions for the correct use and maintenance.
5.1 Design Tests— Samples shall consist of sufficient speci-
1.4 The use and maintenance of this equipment is beyond
mens of each product used in a specific guard system to form
the scope of these test methods.
one of each assembly intended for field use.
1.5 This standard does not purport to address all of the
5.1.1 The design tests will be used to qualify a specific
safety concerns, if any, associated with its use. It is the
product model and normally will not be repeated during
responsibility of the user of this standard to establish appro-
production.
priate safety and health practices and determine the applica-
5.2 Acceptance Tests— A test sample shall consist of one or
bility of regulatory limitations prior to use.
more specimens dependent on the percentage of the lot being
tested.
2. Referenced Documents
5.2.1 A lot is represented either by all the guards produced
2.1 ASTM Standards:
in one production run or in one shipment.
D 149 Test Method for Dielectric Breakdown Voltage and
5.2.2 Lots of new or unused guards shall have test speci-
Dielectric Strength of Solid Electrical Insulating Materials
2 mens selected at random.
at Commercial Power Frequencies
2.2 ANSI Standard:
6. Installation of Assembled Guard System
C39.5 Safety Requirements for Electrical and Electronic
6.1 The guard or assembled guard system is installed on a
conductive electrode (Table 1) to be energized at various
voltages in accordance with the rating of the guard and the type
These test methods are under the jurisdiction of ASTM Committee F-18 on
of test being conducted. The ground electrode shall be a
Electrical Protective Equipment for Workers and are the direct responsibility of
Subcommittee F18.25 on Insulating Cover-Up Equipment.
Current edition approved Feb. 26, 1988. Published April 1988. Originally
published as F 712 – 81. Last previous edition F 712 – 81. Available from American National Standards Institute, 11 West 42nd St., 13th
Annual Book o0f ASTM Standards, Vol 10.01. Floor, New York, NY 10036.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
F 712
TABLE 1 Typical Electrodes for Testing Plastic Guard Equipment
A
Outer Ground Electrode
A
Type of Guards Energized Inner Electrode for All Tests
Proof Test Withstand Voltage Flashover 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
Pole guards, ridge pin and flashover. Therefore, the entire from openings through which the
C
switch blade covers Round metal tube, fabricated mandrel or cluster small area of each cover shall be tested energized electrode protrudes
D
metal tubes. as nearly as practical. during the test only as necessary
DC
Arm guards Round or rectangular metal tube or fabricated mandrel. to avoid flashover at outer ends.
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 guar
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