ASTM D4246-97

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.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: D 4246 – 97 An American National Standard
Standard Specification for
Ozone-Resistant Thermoplastic Elastomer Insulation For
Wire and Cable, 90°C Operation
This standard is issued under the fixed designation D 4246; 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.
TABLE 1 Requirements for Physical Properties
1. Scope
Unaged Requirements:
1.1 This specification covers an ozone-resistant insulating
Tensile strength, min, psi (MPa) 1000 (6.9)
compound for electrical wire and cables 14 AWG and larger.
Elongation at rupture, min, % 300
Aged Requirements (after air oven test at
This compound consists substantially of a thermoplastic elas-
121 6 1°C for 168 h):
tomer.
Tensile strength and elongation, at rupture min, % of 75
1.2 This type of insulation is considered suitable for con-
unaged value
Heat Distortion (at 150 6 1°C, max, % of unaged value):
tinuous operation at conductor temperatures not exceeding
4/0 AWG (107 m ) and smaller (insulation on cable) 50
90°C in dry locations. Operating voltages are not to exceed
Larger than 4/0 AWG (107 mm ) (buffed sample of 50
2000 V. The minimum installation temperature is −40°C.
insulation)
1.3 The values stated in inch-pound units are the standard,
except in cases where SI units are more appropriate. The values
in parentheses are for information only.
thickness for the insulation. The required minimum thickness
1.4 In many instances the insulation cannot be tested unless
is 90 % of the specified average thickness.
it has been formed around a conductor or cable. Therefore,
tests are done on insulated wire or cable in this specification
5. Electrical Requirements
solely to determine the relevant property of the insulation and
5.1 Order of Testing—Perform the ac voltage, insulation
not to test the conductor or completed cable.
resistance, and dc voltage tests in that order when any of these
tests are specified. The sequence of other testing is not
2. Referenced Documents
specified.
2.1 ASTM Standards:
5.2 AC Voltage Test—Unless otherwise specified, omit this
D 470 Test Methods for Crosslinked Insulations and Jackets
test if the dc voltage test described in 5.4 is to be performed.
for Wire and Cable
Test each insulated conductor for 5 min at the ac voltage given
D 2633 Methods of Testing Thermoplastic Insulations and
in Table 1(a) (Conductor Sizes, Insulation Thicknesses, and
Jackets for Wire and Cable
AC Test Voltages, for Rubber Insulations) of Methods D 470
under the columns labelled “Ozone-Resisting Insulations.”
3. Terminology
5.3 Insulation Resistance—The insulated conductor shall
3.1 Definition of Term Specific to This Standard.
have an insulation resistance value of at least that correspond-
3.1.1 aging (act of), n—the exposure of materials to air at
ing to a constant of 10 000 at 60°F (15.6°C).
121°C for 168 h.
5.3.1 If the water temperature at the time measurement was
made differs from 60°F (15.6°C), correct the insulation resis-
4. Physical Properties
tance to 60°F. Table 2, (Temperature Correction Factors for
4.1 Requirements for physical properties are listed in Table
Insulation Resistance at 60°F) of Test Methods D 470 contains
1.
the correction factors. Each insulation manufacturer can fur-
4.2 Thickness of Insulation—Table 1(a), (Conductor Sizes,
nish the 1°F coefficient for the insulation material by using the
Insulation Thicknesses, and AC Test Voltages for Rubber
procedure given in Test Methods D 470. Multiply the measured
Insulations) of Te
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