ASTM D specifies that for insulating fluids to qualify ASTM D – Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using. Page 1. Page 2. Page 3. Page 4. ASTM D DIELECTRIC BREAKDOWN VOLTAGE OF LIQUIDS. This test method describes two procedures, A and B, for determining the electrical breakdown.
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The equipment should produce a straight-line voltage-time curve over the operating range of the equipment. If the allowable range is exceeded, the error is too large.
During testing maintain at least two significant digits for each breakdown. Adjustment and Care of Electrodes and Test Cup 7. This disk is acceptable, however, consideration should be given to machining the disk to a sharp edge because any degradation will make it unacceptable. For severe problems resurfacing may be required. The cup shall be designed to permit easy removal of the electrodes for cleaning and polishing, verification that the sharp edge is within the specified tolerance, and to permit easy adjustment of the gap spacing.
Construct the electrodes of polished brass as disks Axtm residue from asfm buffing must be removed before the electrodes are reinstalled in the test cup. If this occurs, the cup should be warmed slightly to evaporate any 8.
A superscript epsilon e indicates an editorial change since the last revision or reapproval. Immediately after agitation, use a small portion of the sample to rinse the test cup.
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. After adjustment of the gap spacing, the cup shall be rinsed with a dry solvent. Link to Active This link will always route to the current Active version of the standard.
Test Vessel ASTM D, with disc electrodes
We need your help to maintenance this website. This test method should be used as recommended by professional organization standards such as IEEE C Procedure B, modified in accordance with Section 17 of Test Methods Dis acceptable for testing silicone dielectric liquids if the sstm of 1.
It is the responsibility of the user of this standard to establish appropriate safety and health practices d77 determine the applicability of regulatory limitations prior to use. Both sides of the gage are flush with the disk, and the edge of the disk does not fit into the gage. These may include samples taken from circuit breakers, load tap changers, and other liquids heavily contaminated with insoluble particulate material.
A low result in this test method indicates the presence of significant concentrations of one or more of these contaminants in the liquid tested. The gap shall be reset in accordance with 7. Note both edges fit to the edge of the gage and the disk edge fits in the radius with no gap as in D87. These liquids include petroleum oils, hydrocarbons, natural and synthetic esters, and askarels PCB used as insulating and asttm liquids in transformers, cables, and similar apparatus.
The mean of the five breakdowns shall be considered the dielectric breakdown voltage of the sample, provided the range criteria of Note the sharp edge fits into the radius gage and only one side of the gage fits up against the disk while the other side has considerable space. The cup material shall not absorb moisture or the cleaning and test liquids.
Breakdown in this test method is dominated by events occurring at the electrode edges. These liquids include petroleum oils, hydrocarbons, and askarels PCB used as insulating and cooling liquids in transformers, cables, and similar apparatus.
The voltage in the test circuit should be stable enough to be practically unaffected by varying current flowing in the capacitive and resistive paths of the test circuit. Procedure A may be used once r877 single operator precision of has been demonstrated. A low result in this test method indicates the presence of significant concentrations of one or more of these contaminants in the liquid tested. Rapid agitation is undesirable, since an excessive amount of air may be introduced into the liquid.
If the sample shows evidence of free water, the dielectric breakdown test should be waived, and the sample shall be reported as unsatisfactory. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.
In order to permit the escape of air, allow the liquid to stand in the cup for not less than 2 min and not more than 3 min before voltage is applied. This condition requires that the disk be machined back to a sharp edge. It astmm 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.
Historical Version s – view previous versions of standard. Make a voltage breakdown test as specified in this test method.
Test Vessel ASTM D877, with disc electrodes
Procedure A may be used once the single operator precision of ashm Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided ast part of the standard. The use of Procedure B will result in a more accurate value of breakdown voltage when testing such liquids.
It is recommended that the circuit design limit the disruptive current duration and magnitude to low values that will minimize damage to the disks and limit formation of non-soluble materials resulting from the breakdown, but consistent with the requirements of 4.
This test method should be used as recommended by professional organization standards such as IEEE C