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 atness and surface nish of the electrode faces x149-97a be such that the faces are in close contact with the test specimen over the entire c149-97a of the electrodes. It is essential that the test apparatus, and all associated equipment electrically connected to it, be properly designed and installed for safe operation.
They are less critical as to concentricity of the electrodes than are the Types 1 and 2 electrodes. 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. This will usually reduce the probability of surface?
Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards. Results may be affected also by the material from which the electrodes are constructed, since the thermal and discharge mechanism may be inuenced by the thermal conductivity and the work function, respectively, of the electrode material.
Work Item s – proposed revisions of this standard. Ordinarily the rate is selected to approximate the average rate for a step-by-step test. The last approved version of this historical standard is referenced on www.
In addition to the dielectric breakdown voltage, mentioned above, particulate contaminants are especially important when very thin specimens 25 m 1 mil or less are being tested. For research purposes, in some cases it will be of value to conduct tests using more than one time interval on a given material. Due to copyright restrictions, we are not able to provide copies of standards.
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. This standard does not purport to address all of the safety concerns, if any, associated with its use. Link to Active This link d149-97z always ast, to the current Active version of the standard.
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.
It must be recognized that these may give results differing widely from those obtained with other types of electrodes. With the addition of instructions modifying Section 12, this test method is also suitable for use for proof testing. These processes may continue until a complete failure path is formed between the electrodes. At frequencies above D149-7a, dielectric heating may be a problem. If prolonged current follows breakdown it will result in unnecessary burning of the test specimens, pitting of the electrodes, and contamination of any liquid surrounding medium.
Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters. These may cause local erosion or chemical decomposition. 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.
When making high-voltage tests, particularly in compressed gas or in oil, it is possible that the energy released at breakdown will be sufficient to result in?
Aetm spots within the volume under stress sometimes determine the test results. The transformer, its voltage source, and the associated controls shall have the following capabilities: C The electrodes surfaces should be polished and free from irregularities resulting from previous testing.
Other electrodes may be used as specied in ASTM standards or as agreed upon between seller and purchaser where none of these electrodes in the table is suitable for proper evaluation of the material being tested.
Dielectric Strength ASTM D149, IEC 60243
Whitehead10 that in order to avoid discharges in the surrounding medium prior to reaching the breakdown voltage of the solid test specimen, in alternating voltage tests it is necessary d149-7a Em? Solidly f149-97a all electrically conductive parts that any person might come into contact with during the test. Atm breakdown occurs prior to the end of the holding period at any step, the dielectric withstand voltage, Vws, for the specimen is taken as the voltage at the last completed step.
Assurance Enabling you to identify d149–97a mitigate the intrinsic risk in your operations, supply chains and business processes. 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.
The electrode area may have a signicant effect upon what the current setting should be. Since ashover must be avoided and the effects of partial discharges prior to breakdown mimimized, even for short time tests, it is often preferable and sometimes necessary to make the tests in insulating liquid see 6.
Except in cases where the effect of exposure on dielectric strength is being investigated, it is customary to control or limit the relative humidity effects by standard conditioning procedures. However, this test method is suitable for use at any frequency from 25 to Hz. The power rating for most d1449-97a will vary from 0.
The device shall disconnect the voltage-source equipment from the power service and protect it from overload as a result of specimen breakdown causing an overload of the testing apparatus. If no electrodes have been specied, select an applicable one from Table 1, or use other electrodes mutually acceptable to the parties concerned when the standard electrodes cannot be used due to the nature d419-97a conguration of the material being tested.
Surface nish is particularly important when testing very thin materials which are subject to physical damage from improperly nished electrodes. While every effort has been made to include as many as possible of d1499-97a standards referring to Test Method D, the list may not be complete, and standards written or revised after publication sstm this appendix are not included.
G It is acceptable to use other diameters, provided that all parts of the test specimen are at least 15 mm inside the edges of the electrodes. Depending upon the nature of the oil and the properties of the material being tested, other properties, including dissolved gas content, water content, and dissipation factor of the oil may also have an effect upon the results.
It must be recognized that it is possible that these will give results differing widely from those obtained with other types of electrodes. Unless the breakdown path between axtm electrodes is solely within the solid, results in one medium cannot d14-997a compared with those in a different medium. Other dielectric uids may be used as surrounding mediums if specied. This will usually reduce the probability of surface ashover. Commonly used lengths are 20 s and s 5 min.
Dielectric Strength ASTM D, IEC
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. See references in Appendix X2 for examples of some special electrodes. Link to Active This link will always route to the current Active version of the standard. 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.
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 may be desirable to make tests on a given sample at more than 3 one current setting. The options for the specimens are that they be molded or cast, or cut from?