This test method covers, in a preliminary fashion, the
differentiation of similar materials' resistance to the action of a
high-voltage, low-current arc close to the surface of insulation,
when a conducting path is formed causing the material to become
conducting due to the localized thermal and chemical decomposition
The usefulness of this test method is very severely limited by
many restrictions and qualifications, some of which are described
in the following paragraphs and in Section 5. Generally, this test
method shall not be used in material specifications.
Whenever possible, alternative test methods shall be used, and
their development is encouraged.
This test method will not, in general, permit conclusions to be
drawn concerning the relative arc resistance rankings of materials
that are potentially subjected to other types of arcs: for example,
high voltage at high currents, and low voltage at low or high
currents (promoted by surges or by conducting contaminants).
The test method is intended, because of its convenience and the
short time required for testing, for preliminary screening of
material, for detecting the effects of changes in formulation, and
for quality control testing after correlation has been established
with other types of simulated service arc tests and field
experience. Because this test method is usually conducted under
clean and dry laboratory conditions rarely encountered in practice,
it is possible that the prediction of a material's relative
performance in typical applications and in varying "clean to dirty"
environments will be substantially altered (Note 1). Caution is
urged against drawing strong conclusions without corroborating
support of simulated service tests and field testing. Rather, this
test method is useful for preliminary evaluation of changes in
structure and composition without the complicating influence of
environmental conditions, especially dirt and moisture.
NOTE 1-By changing some of the circuit conditions described
herein it has been found possible to rearrange markedly the order
of arc resistance of a group of organic insulating materials
consisting of vulcanized fiber and of molded phenolic and amino
plastics, some containing organic, and some inorganic, filler.
While this test method uses dry, uncontaminated specimen
surfaces, Test Method D2132, Test Methods D2303, and Test Method
D3638 employ wet, contaminated specimen surfaces. Their use is
recommended for engineering purposes and to assist in establishing
some degree of significance to this test method for quality control
This test method is not applicable to materials that do not
produce conductive paths under the action of an electric arc, or
that melt or form fluid residues that float conductive residues out
of the active test area thereby preventing formation of a
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.
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. For specific precautionary
statements, see 6.1.14, 6.1.19, Section 7, and 10.1.1.
2 Also helpful is Test Method D2302 for Wet Tracking
Resistance of Electrical Insulating Materials with Controlled
Water-to-Metal Discharges. This test method was withdrawn and last
appeared in the 1982 Annual Book of ASTM Standards, Part
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