ASTM D149

1.1 This test method covers procedures for the determination of dielectric strength of solid insulating materials at commercial power frequencies, under specified conditions.^,

1.2 Unless otherwise specified, the tests shall be made at 60 Hz. However, this test method may be used at any frequency from 25 to 800 Hz. At frequencies above 800 Hz, dielectric heating may be a problem.

1.3 This test method is intended to be used in conjunction with any ASTM standard or other document that refers to this test method. References to this document should specify the particular options to be used (see ).

1.4 It may be used at various temperatures, and in any suitable gaseous or liquid surrounding medium.

1.5 This test method is not intended for measuring the dielectric strength of materials that are fluid under the conditions of test.

1.6 This test method is not intended for use in determining intrinsic dielectric strength, direct-voltage dielectric strength, or thermal failure under electrical stress (see Test Method D 3151).

1.7 This test method is most commonly used to determine the dielectric breakdown voltage through the thickness of a test specimen (puncture). It may also be used to determine dielectric breakdown voltage along the interface between a solid specimen and a gaseous or liquid surrounding medium (flashover). With the addition of instructions modifying Section , this test method may be used for proof testing.

1.8 This test method is similar to IEC Publication 243-1. All procedures in this method are included in IEC 243-1. Differences between this method and IEC 243-1 are largely editorial.

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. Specific hazard statements are given in Section . Also see .

2. Referenced Documents

D1711 Terminology Relating to Electrical Insulation
D2413 Practice for Preparation of Insulating Paper and Board Impregnated with a Liquid Dielectric
D3151 Test Method for Thermal Failure of Solid Electrical Insulating Materials Under Electric Stress
D3487 Specification for Mineral Insulating Oil Used in Electrical Apparatus
D374 Test Methods for Thickness of Solid Electrical Insulation
D5423 Specification for Forced-Convection Laboratory Ovens for Electrical Insulation
D618 Practice for Conditioning Plastics for Testing
D877 Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes
C68.1 Techniques for Dielectric Tests, IEEE Standard No. 4
Pub. 243-1 Methods of Test for Electrical Strength of Solid Insulating Materials-Part 1: Tests at Power Frequencies

Index Terms

breakdown; breakdown voltage; calibration; criteria of breakdown; dielectric breakdown voltage; dielectric failure; dielectric strength; electrodes; flashover; power frequency; process-control testing; proof testing; quality-control testing; rapid rise; research testing; sampling; slow rate-of-rise; step-by-step; surrounding medium; voltage withstand

Citing ASTM Standards

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