ASTM F712-88(2000)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:F 712–88(Reapproved 2000)
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 C39.5 Safety Requirements for Electrical and Electronic
Measuring and Controlling Instrumentation
1.1 These test methods cover three electrical tests on plastic
guards and assembled guard systems. They are:
3. Significance and Use
1.1.1 Method A—Withstand voltage proof test,
3.1 All three tests may be used for product design qualifi-
1.1.2 Method B—Flashover voltage, and
cation.
1.1.3 Method C—Leakage current.
1.2 These methods cover, but are not limited to, the follow-
4. Apparatus
ing typical guards:
4.1 Voltage Source and Test Techniques—See Test Method
1.2.1 Conductor Guards and Connecting Covers:
D 149. The test equipment shall have adequate power and
1.2.1.1 Line guards,
provide relatively stepless variable test voltage that can be
1.2.1.2 Line guard connectors,
raised at a rate of approximately 1000 V/s ac or 3000 V/s dc.
1.2.1.3 Insulator covers, and
4.2 Energized Inner Electrodes, in accordance with Table 1
1.2.1.4 Deadend covers.
and Table 2. The length should be sufficient to extend past the
1.2.2 Structure and Apparatus Covers:
ends of the guard or guard assemblies where appropriate.
1.2.2.1 Pole guards,
4.3 Outer Ground Electrode—A conductive material with
1.2.2.2 Ridge pin covers,
size and location as indicated in Table 1.
1.2.2.3 Switch blade covers,
4.4 Shielded Cable— To reduce the “room influence” when
1.2.2.4 Arm guards,
conducting ac leakage tests, the cable from the pickup elec-
1.2.2.5 Cutout covers, and
trode to the current-measuring device should be a shielded
1.2.2.6 Structural barriers,
cable with the cable shield grounded.
1.3 It is common practice for the user of this equipment to
prepare instructions for the correct use and maintenance.
5. Sampling
1.4 The use and maintenance of this equipment is beyond
5.1 Design Tests— Samples shall consist of sufficient speci-
the scope of these test methods.
mens of each product used in a specific guard system to form
1.5 This standard does not purport to address all of the
one of each assembly intended for field use.
safety concerns, if any, associated with its use. It is the
5.1.1 The design tests will be used to qualify a specific
responsibility of the user of this standard to establish appro-
product model and normally will not be repeated during
priate safety and health practices and determine the applica-
production.
bility of regulatory limitations prior to use.
5.2 Acceptance Tests—Atest sample shall consist of one or
more specimens dependent on the percentage of the lot being
2. Referenced Documents
tested.
2.1 ASTM Standards:
5.2.1 A lot is represented either by all the guards produced
D 149 Test Method for Dielectric Breakdown Voltage and
in one production run or in one shipment.
Dielectric Strength of Solid Electrical Insulating Materials
2 5.2.2 Lots of new or unused guards shall have test speci-
at Commercial Power Frequencies
mens selected at random.
2.2 ANSI Standard:
6. Installation of Assembled Guard System
6.1 The guard or assembled guard system is installed on a
These test methods are under the jurisdiction of ASTM Committee F18 on
conductive electrode (Table 1) to be energized at various
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 International, 100 Barr Harbor Drive, PO Box C700, 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 guard system is to be applied.
E
Metal canisters made for storing rubber blanke
...