ASTM D2477-07(2012)

Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Insulating Gases at Commercial Power Frequencies

SIGNIFICANCE AND USE
4.1 The dielectric breakdown voltage and dielectric strength of an insulating gas in a uniform field depends primarily on the molecular structure of the gas. As different gases are mixed either by plan or by contamination, any change in dielectric breakdown voltage and dielectric strength will depend on both the nature and proportion of the individual gases. This test method uses plane and spherical electrodes which provide a nearly uniform field (see Appendix) in the area of electrical discharge. It is suitable for determining the dielectric breakdown voltage and dielectric strength of different gases and mixtures thereof for research and application evaluations and also as a field test. A more complete discussion of the significance of the dielectric strength test is given in the Appendix.
SCOPE
1.1 This test method covers the determination of the dielectric breakdown voltage and dielectric strength of insulating gases used in transformers, circuit breakers, cables, and similar apparatus as an insulating medium. The test method is applicable only to gases with boiling points below room temperature at atmospheric pressure.  
1.2 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. 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.  
1.3 Mercury has been designated by EPA and many state agencies as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA's website — http://www.epa.gov/mercury/faq.htm for additional information. Users should be aware that selling mercury and/or mercury containing products into your state may be prohibited by state law.

General Information

• Status: Historical
• Publication Date: 30-Apr-2012
• ICS: 29.040.20 - Insulating gases
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.05 - Electrical Test

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D2477 − 07 (Reapproved 2012)
Standard Test Method for
Dielectric Breakdown Voltage and Dielectric Strength of
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Insulating Gases at Commercial Power Frequencies
This standard is issued under the fixed designation D2477; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.3 ASTM Adjuncts:
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Dielectric cell assembly and detail (2 drawings)
1.1 This test method covers the determination of the dielec-
tric breakdown voltage and dielectric strength of insulating
3. Terminology
gases used in transformers, circuit breakers, cables, and similar
apparatus as an insulating medium. The test method is appli- 3.1 Definitions:
cableonlytogaseswithboilingpointsbelowroomtemperature 3.1.1 For definitions of terms used in this test method, refer
at atmospheric pressure. to Terminology D2864.
1.2 This standard may involve hazardous materials,
4. Significance and Use
operations, and equipment. This standard does not purport to
address all of the safety concerns, if any, associated with its
4.1 The dielectric breakdown voltage and dielectric strength
use. It is the responsibility of the user of this standard to of an insulating gas in a uniform field depends primarily on the
establish appropriate safety and health practices and deter-
molecular structure of the gas. As different gases are mixed
mine the applicability of regulatory limitations prior to use. either by plan or by contamination, any change in dielectric
1.3 Mercury has been designated by EPA and many state
breakdown voltage and dielectric strength will depend on both
agencies as a hazardous material that can cause central the nature and proportion of the individual gases. This test
nervous system, kidney and liver damage. Mercury, or its method uses plane and spherical electrodes which provide a
vapor, may be hazardous to health and corrosive to materials. nearly uniform field (see Appendix) in the area of electrical
Caution should be taken when handling mercury and mercury discharge. It is suitable for determining the dielectric break-
containing products. See the applicable product Material down voltage and dielectric strength of different gases and
Safety Data Sheet (MSDS) for details and EPA’s website — mixtures thereof for research and application evaluations and
http://www.epa.gov/mercury/faq.htm for additional informa-
also as a field test. A more complete discussion of the
tion. Users should be aware that selling mercury and/or significance of the dielectric strength test is given in the
mercury containing products into your state may be prohibited
Appendix.
by state law.
5. Apparatus
2. Referenced Documents
5.1 Electrical Apparatus:
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2.1 ASTM Standards:
5.1.1 Transformer— The desired test voltage may be most
D2864 Terminology Relating to Electrical Insulating Liq-
readily obtained by a step-up transformer energized from a
uids and Gases
variable low-voltage commercial power frequency source. The
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2.2 IEEE Standard:
transformer and controlling element shall be of such size and
No. 4 Standard Techniques for High Voltage Testing
designthat,withthetestspecimeninthecircuit,thecrestfactor
(ratio of maximum to mean effective) of the 60-Hz test voltage
does not differ by more than 65 % from that of a sinusoidal
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This test method is under the jurisdiction of ASTM Committee D27 on
wave over the upper half of the range of test voltage. The crest
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
mittee D27.05 on Electrical Test.
factor may be checked by means of an oscilloscope, a sphere
Current edition approved May 1, 2012. Published May 2012. Originally
gap, or a peak-reading voltmeter in conjunction with an rms
approved in 1966. Last previous edition approved in 2007 as D2477 – 07. DOI:
voltmeter. Where the waveform cannot be determined
10.1520/D2477-07R12.
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For referenced ASTM standards, visit the ASTM website, www.astm.org, or conveniently, a transformer having a rating of not less than ⁄2
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
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Available from The Institute of Electrical and Electronic Engineers, Inc. Detaileddrawingsofthisapparatusareavailableatanominalcostfrom:ASTM
(IEEE), 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331. International Headquarters. Order Adjunct No. ADJD2477.
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