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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Discharges may occur in any internal voids or bubbles that are present or may develop. This form of breakdown is generally irreversible.

If the liquid immersion medium is a low loss material, the criterion simpli? Work Item s – proposed revisions of this standard. These may cause local erosion or chemical d149-97z. Visual observation of the electrodes and test specimen during the test is frequently desirable.

Dielectric Strength ASTM D149, IEC 60243

In any event the electrodes must be described in the d149-79a. Differences between this method and IEC are largely editorial. Metal baths must be grounded.

Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility. Differences between this method and IEC are largely editorial.

Current edition approved March 1, Unless otherwise specied, measure the thickness after the test in the immediate vicinity of the s149-97a of breakdown. In this case, the times to failures shall be made a part of the report. The transformer, its ashm source, and the associated controls shall have the following capabilities: In the case of solids that can be melted and poured to solidify between?

Design test equipment, test chambers, and test specimens so as to minimize the possibility of such occurrences and to eliminate the possibility of personal injury. Whether your business is local or global, we can ensure your products meet quality, health, environmental, safety, and social accountability standards for virtually any market around the world. Hence, its importance will depend to a large extent upon the nature of the material being tested.

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Commonly atm lengths are 20 s and s 5 min. In most cases it is necessary that these results be evaluated by comparison with results obtained from other functional tests or from tests on other materials, or both, in order to estimate their signi? Approved October 1, 1 The standard was revised throughout to remove nonmandatory language.

Send us a request Wilton UK: The breakdown mechanisms usually operate in r149-97a rather than singly. D — 97a 6.

Because of this it is important to measure the concentration of ozone in the atmosphere, using commercially wstm monitoring devices, whenever the odor of ozone is persistently present or when ozone generating conditions d14-997a. In most cases it is necessary that these results be evaluated by comparison with results obtained from other functional tests or from tests on other materials, or both, in order to estimate their signicance for a particular material.

D — 09 9. Summary of Test Method 4. When resurfacing, do not change the transition between the electrode face and any specied edge radius.

d149-97q The dielectric breakdown voltage test represents a convenient preliminary test to determine whether a material merits further consideration, but it falls short of a complete evaluation in two important respects.

Small baths can in some cases be placed in an oven see 6. Specific hazard statements are given in Section 7.

These include, but are not limited to, silicone uids and other liquids intended for use asmt transformers, circuit breakers, capacitors, or cables. For thin materials it may be convenient to use specimens large enough to permit making more than one test on a single piece. Set the sensing element to respond to a current that is indicative of specimen breakdown as de? Second, in service there are deteriorating in?

Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Work Item s d149-97q proposed revisions of this standard.

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Tests made with horizontal electrodes should not be directly asstm with tests made with vertical electrodes, particularly when the tests are made in a liquid surrounding medium. If dissimilar electrodes are used such as Type 6 of Table 1 and only one surface is to be machined, the larger of the two electrodes shall be in contact with the machined surface.

Dielectric Strength ASTM D, IEC

Dielectric Strength is a measure of the electrical strength of a material as an insulator. Repeated applications of voltage will sometimes result in failure at lower voltages sometimes unmeasurably lowusually with additional damage at the breakdown area. Electrostatic voltmeters, voltage dividers, or potential transformers having comparable accuracy may be used for calibration measurement.

Transformer oil is usually speci? Techniques that may be used to prevent ashover, or to reduce partial discharge corona include: In many cases the dielectric strength of a material will be the determining factor in the design of the apparatus in which it is to be used.

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

Within the limits speci? Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided astk part of the standard. Second, in service there are deteriorating inuences, heat, mechanical stress, corona and its products, contaminants, and so forth, which may reduce the breakdown voltage far below its value as originally installed.

astj The electrode area may have a signicant effect upon what the current setting should be. 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.