ASTM D149-97A PDF

Buy ASTM Da() Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at. Dielectric Strength ASTM D, IEC Scope: Dielectric Strength is a measure of the electrical strength of a material as an insulator. Dielectric strength is. ASTM DA – Designation: D – 97a (Reapproved ) An American National Standard Standa.

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The electrodes must not damage the specimen upon contact. Use the short-time test unless otherwise speci? This phenomenon is most commonly evidenced during the test by an abrupt visible and audible rupture through the thickness of the specimen, resulting in a visible puncture and decomposition of the specimen in the breakdown area.

Visual observation of the electrodes and test specimen during the test is frequently desirable. The test is sometimes performed in oil to prevent arcing from the electrode to the ground. If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below.

Dielectric Strength ASTM D, IEC

Summary of Test Method 4. If failure occurred while the voltage was being increased to the starting voltage the failure time shall be zero. However, this test method may be used at any frequency from 25 to Hz. Global Reach Intertek is the industry leader with over 42, people in 1, locations in over d14-97a.

Conditioning times for these materials should be sufficiently long to permit the specimens to reach moisture equilibrium as well as temperature equilibrium.

Therefore there is a great need for a test to evaluate the performance of particular materials at high voltage stress.

Dielectric Strength ASTM D149, IEC 60243

The power rating for most tests will vary from 0. For most materials, using electrodes similar to those shown in Table 1, an output current capacity of 40 mA is usually satisfactory. A number of different physical arrangements of voltage source, measuring equipment, baths or ovens, and electrodes are possible, but it is essential that 1 all gates or doors providing access to spaces in which there are electrically energized parts be interlocked to shut off the voltage source when opened; 2 clearances are sufficiently large that the eld in the area of the electrodes and specimen are not distorted and that ashovers and partial discharges corona do not occur except between the test electrodes; and 3 insertion and replacement of specimens between tests be as simple and convenient as possible.

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B Electrodes are normally made from either brass or stainless steel. All procedures in this method are included in IEC In general, the breakdown voltage will tend to increase with increasing rate of voltage application.

D — 97a Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. For such materials, the bath must be of such design that it will not be necessary to expose the specimens to air before testing.

It is essential that for these materials both the specimen and the electrodes be de? Since the electrode separation can be?

References to this document need to specify the particular options to be used see 5. Specific hazard statements are given in Section 7. Small baths can d149-9a some cases be placed in an oven see 6.

The test values are dependent upon specimen geometry, electrodes, and other variable factors, in addition to the properties of the sample, so that it is not possible to make a statement of bias. If asperities have developed, astmm must be removed. If a test set with motor-driven voltage control is available, the slow rate-of-rise test is simpler and preferable to the step-by-step test. Specific hazard statements are given in Section.

Some of these effects can be incorporated in laboratory tests, and a better estimate of the material will result, but the? The optimum current setting is not the same for all specimens and depending upon the intended use of the material and the purpose of the test, it is often desirable to make tests on a given sample at 3 more than one current d149-97s.

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D-7, Glenway Ave. With solid materials the discharges usually occur in the surrounding medium, thus increasing the test area and producing failure at or beyond the electrode edge. Electrostatic voltmeters, voltage dividers, or potential transformers having comparable accuracy may be used for calibration measurement.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in d149-97w standard.

For the most common test, the short-time method, voltage is applied across the two electrodes and raised from zero to dielectric breakdown at a uniform rate. Each of these three methods has the same basic set-up, which consists of the test specimen placed between two electrodes in air or oil. Precision and Bias Do not allow the peak voltage to exceed 1.

Make the setting high enough that transients, such as partial discharges, will not trip the breaker but not so high that excessive burning of the specimen, with resultant electrode damage, will occur on breakdown.

Because of this it is important to measure the concentration of ozone in the atmosphere, using commercially available monitoring devices, whenever the odor of ozone is persistently present or when ozone generating conditions continue. Materials so affected shall be brought to equilibrium with an atmosphere of controlled temperature and relative humidity before testing.

Frequent replacement of the oil, or the use of lters and other reconditioning equipment may be necessary to minimize the effect of variations of the quality of the oil on the test results. The voltage source must trip rapidly at relatively low current for this type of failure to occur.

A superscript epsilon e indicates an editorial change since the last revision or reapproval.