ASTM D2413-99(2009)
(Test Method)Standard Practice for Preparation of Insulating Paper and Board Impregnated with a Liquid Dielectric
Standard Practice for Preparation of Insulating Paper and Board Impregnated with a Liquid Dielectric
SIGNIFICANCE AND USE
Dissipation Factor and Relative Permittivity—Knowledge of these properties is important in the design of electrical equipment such as cables, transformers, insulators, etc. The numerical product of these two properties of a dielectric system is proportional to the energy loss converted to heat, and is called its loss index (see Terminology D1711). The energy loss reduces the efficiency of electrical equipment. The heat produced tends to chemically degrade the dielectric material and may even lead to thermal runaway. Test results of impregnated specimens can disclose significant differences between combinations of papers and oils that appear similar when the papers and the oils are tested separately. Dissipation factor, particularly at elevated temperatures, is often changed significantly by the presence of a small quantity of impurities in either the liquid or the paper. This practice is useful in the comparison of materials and in evaluating the effects of different papers on a given liquid. Judicious analysis of results with respect to time, temperature, and field strength should be useful in predicting the performance and capabilities of systems using the paper and the liquid. For additional information on the significance of dissipation factor and relative permittivity, see Test Methods D150.
Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies:
A comprehensive discussion of the significance of the dielectric strength test as applied to solid, semi-solid, and liquid materials is given in Appendix X1 of Test Method D149. Other factors peculiar to high-quality composite insulations, such as oil-impregnated papers, are considered in the following:
In tests involving high electrical stresses, immersion of critical parts of a test circuit in oil is a widely used technique for inhibiting corona. However, it has limitations that must be recognized when using the submerged el...
SCOPE
1.1 This practice covers the preparation of insulating paper and board impregnated with a liquid dielectric. Where this practice states only “paper,” the same procedure shall apply to board.
1.2 This practice has been found practicable for papers having nominal thickness of 0.05 mm (2 mil) and above. It has been used successfully for insulating board as thick as 6 mm (¼ in.) when care is taken to ensure the specimen geometry necessary for valid measurement of dielectric properties. Suitable geometry depends on the electrode system used. Rigid solid opposing electrodes require flat specimens that have essentially parallel surfaces.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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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: D2413 − 99(Reapproved 2009)
Standard Practice for
Preparation of Insulating Paper and Board Impregnated with
a Liquid Dielectric
This standard is issued under the fixed designation D2413; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope cal Insulating Liquids
D1711Terminology Relating to Electrical Insulation
1.1 This practice covers the preparation of insulating paper
D1816Test Method for Dielectric Breakdown Voltage of
and board impregnated with a liquid dielectric. Where this
Insulating Liquids Using VDE Electrodes
practice states only “paper,” the same procedure shall apply to
D1933Specification for Nitrogen Gas as an Electrical Insu-
board.
lating Material
1.2 This practice has been found practicable for papers
D3394Test Methods for Sampling and Testing Electrical
havingnominalthicknessof0.05mm(2mil)andabove.Ithas
Insulating Board
been used successfully for insulating board as thick as 6 mm
D3426Test Method for Dielectric Breakdown Voltage and
( ⁄4 in.) when care is taken to ensure the specimen geometry
DielectricStrengthofSolidElectricalInsulatingMaterials
necessary for valid measurement of dielectric properties. Suit-
Using Impulse Waves
able geometry depends on the electrode system used. Rigid
solid opposing electrodes require flat specimens that have
3. Terminology
essentially parallel surfaces.
3.1 Definitions—Use Terminology D1711 for definitions of
1.3 The values stated in SI units are to be regarded as
terms used in this practice and associated with electrical or
standard. No other units of measurement are included in this
electronic materials.
standard.
4. Summary of Practice
2. Referenced Documents
4.1 The paper is heated and vacuum dried and the liquid
2.1 ASTM Standards:
dielectric degassed. The paper may be dried in loose form or
D117Guide for Sampling, Test Methods, and Specifications
assembled between electrodes. The liquid dielectric may be
for Electrical Insulating Oils of Petroleum Origin
heated and degassed prior to introducing it into the chamber
D149Test Method for Dielectric Breakdown Voltage and
containing the dried paper or it may be degassed as it is
DielectricStrengthofSolidElectricalInsulatingMaterials
introduced into the evacuated chamber containing the dried
at Commercial Power Frequencies
paper.Asufficient length of time is allowed for the impregnat-
D150Test Methods forAC Loss Characteristics and Permit-
ingprocessdependingontheapparentdensityofthepaperand
tivity (Dielectric Constant) of Solid Electrical Insulation
method of impregnation. The impregnated specimens are
D202Test Methods for Sampling and Testing Untreated
subsequently tested for various selected electrical properties.
Paper Used for Electrical Insulation
D257Test Methods for DC Resistance or Conductance of
5. Significance and Use
Insulating Materials
5.1 Dissipation Factor and Relative Permittivity
D924Test Method for Dissipation Factor (or Power Factor)
—Knowledge of these properties is important in the design of
and Relative Permittivity (Dielectric Constant) of Electri-
electrical equipment such as cables, transformers, insulators,
etc. The numerical product of these two properties of a
This practice is under the jurisdiction of ASTM Committee D09 on Electrical
dielectricsystemisproportionaltotheenergylossconvertedto
and Electronic Insulating Materials and is the direct responsibility of Subcommittee
heat,andiscalleditslossindex(seeTerminologyD1711).The
D09.01 on Electrical Insulating Products.
energy loss reduces the efficiency of electrical equipment. The
Current edition approved Oct. 1, 2009. Published February 2010. Originally
heat produced tends to chemically degrade the dielectric
approved in 1965. Last previous edition approved in 2005 as D2413–99(2005).
DOI: 10.1520/D2413-99R09.
material and may even lead to thermal runaway.Test results of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
impregnated specimens can disclose significant differences
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
between combinations of papers and oils that appear similar
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. when the papers and the oils are tested separately. Dissipation
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2413 − 99 (2009)
factor, particularly at elevated temperatures, is often changed selected temperatures as high as 115°C. The chamber shall
significantly by the presence of a small quantity of impurities have a connection, through a suitable vapor trap, to a vacuum
in either the liquid or the paper. This practice is useful in the pump capable of maintaining selected absolute pressures as
comparison of materials and in evaluating the effects of lowas75Pa(0.5Torr),asmeasuredbyasuitablevacuumgage
different papers on a given liquid. Judicious analysis of results having a connection to the chamber separate from that of the
with respect to time, temperature, and field strength should be vacuum pump. It shall be constructed of materials that will not
useful in predicting the performance and capabilities of sys- contaminate either the liquid dielectric or the paper, and shall
tems using the paper and the liquid. For additional information includeanappropriatelyvalvedentryfortheliquidplusabaffle
on the significance of dissipation factor and relative for the purposes indicated in 9.3.
permittivity, see Test Methods D150. 6.1.2 Vacuum Drying Equipment—For the liquid, if Proce-
dure 1 (9.2.1) is to be used. This may be substantially a
5.2 Test Method for Dielectric Breakdown Voltage and
duplicate of the impregnating chamber except that a valved
Dielectric Strength of Solid Electrical Insulating Materials at
vacuum-tightlineisrequiredfortransferringdriedliquidtothe
Commercial Power Frequencies:
impregnating chamber. Baffles may be used to expose thin
5.2.1 Acomprehensive discussion of the significance of the
films of incoming liquid to the drying and degassing effect of
dielectric strength test as applied to solid, semi-solid, and
heat and vacuum.
liquidmaterialsisgiveninAppendixX1ofTestMethodD149.
Other factors peculiar to high-quality composite insulations, 6.2 Equipment for Measuring Dissipation Factor (Power
such as oil-impregnated papers, are considered in the follow- Factor) and Permittivity of Liquid Dielectric—The equipment
ing: and test cell shall be any three-terminal system meeting the
5.2.2 In tests involving high electrical stresses, immersion requirements set forth in Test Method D924.
ofcriticalpartsofatestcircuitinoilisawidelyusedtechnique
6.3 Equipment for Measuring Dielectric Strength at Com-
for inhibiting corona. However, it has limitations that must be
mercial Power Frequencies:
recognized when using the submerged electrode option of this
6.3.1 Theequipmentformeasuringthedielectricstrengthof
practice (Note 1). Attack on the paper by corona generated in
the paper shall be as described in Test Method D149, except
the surrounding fluid at electrode edges can occur whether the
that the electrodes shall be as specified in Test Methods D202
fluidisairoroil.Coronaoccursatconsiderablyhighervoltages
or D3394, as applicable.
in oil than in air. Thick and dense papers are more likely to
6.3.2 Theequipmentfortestingthedielectricstrengthofthe
cause discharge-initiated breakdowns. For interpretation of
liquid shall be as described in Test Method D1816.
breakdown measurements the number of edge breakdowns,
6.4 Equipment for measuring impulse withstand strength
implying discharge-initiated breakdowns, should be consid-
and impulse breakdown dielectric strength shall be that which
ered.
is specified in Test Method D3426.
NOTE 1—Two techniques are in use in the industry for testing
specimens for dielectric breakdown voltage. In one, the test is made with
7. General Considerations
the electrodes and test specimen submerged in the impregnating liquid
while in the other the electrodes are not submerged, that is, the specimen
7.1 When undertaking an investigation into the electrical
istestedinair.Muchdatahasbeenaccumulatedusingthelattertechnique.
properties of various papers that are to be impregnated with a
These techniques yield different values of breakdown voltage. Test
specific liquid dielectric or a specific paper to be impregnated
Method D149 states preference for testing
...
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