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 breakdown mechanisms usually operate in combination rather than singly.
Users of d14-97a 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. D Refer to the appropriate standard for the load force applied by the upper electrode assembly. However, the longer-time tests, Methods B and C, which usually will give lower test results, will potentially give more meaningful results when different materials are being compared with each other.
Active view current version of standard. It shall have a dielectric breakdown voltage as d149-97q by Test Method D of at least 26 kV.
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. These include, but are not limited to, silicone? However, this test method may be used at any frequency from 25 to Hz.
C The electrodes surfaces shall be polished and free from irregularities resulting from previous testing. Breakdown is when an electrical burn-through punctures the sample, or decomposition occurs in the specimen. At frequencies above Hz, dielectric heating may be a problem. Ordinarily the rate is selected to approximate the average rate for a step-by-step test. 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 setting.
Dielectric Strength ASTM D, IEC
Avoid the outer few layers of roll material, the top sheets of a package of sheets, or material immediately next to an edge of a sheet or roll, unless the presence or proximity of defects d149-97q discontinuities is of interest in the investigation of the material.
Calibrate the currentsensing dial in terms of specimen current. The transformer, ashm voltage source, and the associated controls shall have the following capabilities: Provide means for use at the completion of any test to ground any parts which fall into any of the following cases: Method A is the most commonly-used test for quality-control tests.
When making duplicate tests on? Tests made with horizontal electrodes should not be directly compared with tests made with vertical electrodes, particularly when the tests are made in a liquid surrounding medium.
This is to be expected because the thermal breakdown mechanism r149-97a time-dependent and the discharge mechanism is usually time-dependent, although in some cases the latter mechanism may cause rapid failure by producing critically high local? These processes may continue until a complete failure path is formed between the electrodes. These processes may continue until a complete failure path is formed between the electrodes. 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.
The material of the gaskets or seals around the electrodes has the potential to in? With the exception of Type 5 electrodes, no attempt has been made to suggest electrode systems for other than at surface material.
Therefore there is a great need for a test to evaluate the performance of particular materials at high d1449-97a stress.
D — 97a Reapproved An American National Standard Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies1 This standard is issued under the xed designation D ; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. Dielectric strength is defined as the maximum voltage required to produce a d14997a breakdown axtm the material and is expressed as Volts per unit thickness.
ASTM D 97a The design of such chambers will be determined by the nature of the test program to be undertaken. When making a direct comparison of results from two or more laboratories, evaluate the precision between the laboratories.
Small baths can in some cases be placed in d149-79a oven see 6. For such materials, the bath must be of such design that it will not be necessary to expose the specimens to air before testing. C The electrodes surfaces should be polished and free from irregularities resulting from previous testing.
Dielectric Strength ASTM D149, IEC 60243
This critical eld intensity d1499-7a called the intrinsic dielectric strength. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.
Do not allow the peak voltage to exceed 1. This form of breakdown is generally irreversible.
Conditioning times for these materials shall be sufficiently long to permit the specimens to reach moisture equilibrium as well as temperature equilibrium. The exposure limits are set by governmental agencies and are usually based upon recommendations made by the American Conference of Governmental Industrial Hygienists.
They are less critical as to concentricity of the electrodes than are the Types 1 and 2 electrodes. 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.
If the control is set too high, the circuit will not respond when breakdown occurs; if set too low, it is possible that it will respond to leakage currents, capacitive currents, or partial discharge corona currents or, when the sensing element is located in the primary, to the step-up transformer magnetizing current.
Dielectric breakdown often occurs in an area of the test specimen other than that where the eld intensity is greatest and sometimes in an area remote from the material 9 directly between the electrodes.
If the items listed in 5. It is recommended that mineral oil meeting the requirements of Speci? Test results are also affected by the electrode geometry. At frequencies above Hz dielectric heating may be a problem. The following discussion applies only to solid and semisolid materials.
Motor-driven controls are preferable for making short-time see