ASTM D3300-00
(Test Method)Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Under Impulse Conditions
Standard Test Method for Dielectric Breakdown Voltage of Insulating Oils of Petroleum Origin Under Impulse Conditions
SCOPE
1.1 This test method covers the determination of the dielectric breakdown voltage of insulating oils in a highly divergent field under impulse conditions.
1.2 The values stated in inch-pound units are to be regarded as the standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D 3300–00
Standard Test Method for
Dielectric Breakdown Voltage of Insulating Oils of
Petroleum Origin Under Impulse Conditions
This standard is issued under the fixed designation D 3300; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope expected for a given fresh oil may also indicate use or
contamination of that oil.
1.1 This test method covers the determination of the dielec-
3.3 Although polarity of the voltage wave has little or no
tric breakdown voltage of insulating oils in a highly divergent
effect on the breakdown strength of an oil in uniform fields,
field under impulse conditions.
polaritydoeshaveamarkedeffectonthebreakdownvoltageof
1.2 The values stated in inch-pound units are to be regarded
an oil in nonuniform electric fields.
as the standard.
3.4 Transient voltages may also vary over a wide range in
1.3 This standard does not purport to address all of the
both the time to reach crest value and the time to decay to half
safety concerns, if any, associated with its use. It is the
crest or to zero magnitude. The IEEE standard lightning
responsibility of the user of this standard to establish appro-
impulse test (see 2.2) specifies a 1.2 by 50-µs negative polarity
priate safety and health practices and determine the applica-
wave.
bility of regulatory limitations prior to use.
4. Apparatus
2. Referenced Documents
4.1 Impulse Generator, capable of producing a standard 1.2
2.1 ASTM Standards:
by 50-µs full wave adjustable to positive or negative polarity.
D 923 Practices for Sampling Electrical Insulating Liquids
The generator shall have a nominal voltage rating of at least
D 2864 Terminology Relating to Electrical Insulating Liq-
300 kV adjustable in 10-kV steps. Generators having a
uids and Gases
capability of 1000 W·s (1000 J) at 300 kV have been found
2.2 IEEE Documents:
satisfactory.
IEEE Standard 4-1995 Techniques for High-Voltage Test-
4.2 Voltage-Control Equipment—The controls shall include
ing
a suitable measuring device for predetermining the crest
3. Significance and Use voltage to within 65 %.Avoltage stabilizer is desirable at the
input to the d-c power supply used for charging the impulse-
3.1 This test method is most commonly performed using a
generator capacitors.
negativepolaritypointopposingagroundedsphere(NPS).The
4.3 Electrodes:
NPS breakdown voltage of fresh unused oils measured in the
4.3.1 Theelectrodesshallconsistofapolishedsteelorbrass
highly divergent field in this configuration depends on oil
sphere of 0.5 in. (12.7 mm) diameter and a steel point. The
composition, decreasing with increasing concentration of aro-
point may be an ordinary steel phonograph needle with a 0.06
matic, particularly polyaromatic, hydrocarbon molecules.
mm 6 20 % radius of curvature of point or a No. 18 Filter
3.2 This test method may be used to evaluate the continuity
Point needle. Needles with drawn tips are not recommended.
of composition of an oil from shipment to shipment. The NPS
4.3.2 The effect of variation in the radius of curvature of
impulse breakdown voltage of an oil can also be substantially
point is subject to further investigation. Both electrodes shall
lowered by contact with materials of construction, by service
be easily replaceable.
aging, and by other impurities. Test results lower than those
4.4 Test Cell:
4.4.1 The test cell shall be made of a material of high
dielectric strength and of such dimensions that the electrical
This test method is under the jurisdiction of ASTM Committee D27 on
breakdown is restricted to the electrode gap.Test cell materials
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
shall resist attack by, and be insoluble in, any of the cleaning
mittee D27.05 on Electrical Test.
Current edition approved Dec. 10, 2000. Published February 2001. Originally
published as D 3300 – 74. Last previous edition D 3300 – 94.
2 4
Annual Book of ASTM Standards, Vol 10.03. The following steel needle has been found satisfactory for this method: Dean
Available from the Institute of Electrical and Electronics Engineers, 445 Hoes No. 18 Filter Point Needle, available from John Dean, Inc., 20 Mechanic St.,
Lane, Piscataway, NJ 08855-1331. Putnam, CT 06260.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 3300–00
ortestliquidsused.TestcellssuchasthoseshowninFig.1and 6.1.3 The gap spacings shall be 1.0 in. (25.4 mm) for
Fig. 2 have been found satisfactory. point-to-sphere and 0.15 in. (3.8 mm) for sphere-to-sphere
4.4.2 The sphere electrode shall be rigidly fixed and the
electrode configuration.
point electrode mounted such that the gap may be adjusted
6.2 Cleaning—Degrease the cell and electrodes by rinsing
from zero to the required value.
them with reagent grade petroleum ether, washing with deter-
gent and hot water, rinsing thoroughly in hot tap water, and
5. Sampling
then rinsing them with distilled water. Dry the cell and
5.1 Obtain a sample of the liquid to be tested using
hardware in an oven for 2 h at approximately 105 to 110°C,
appropriate ASTM sampling apparatus in accordance with
remove, and store in a desiccator until needed.
Practices D 923.
6.3 Daily Use—Use new or polished sphere electrodes at
6. Adjustments and Care of Electrodes and Test Cell
the beginning of each day’s testing. Discard the point electrode
and replace it after each breakdown; replace the sphere
6.1 Electrode Spacing:
electrodes after every five breakdowns when testing point-to-
6.1.1 For the cell shown in Fig. 1, reduce the electrode gap
sphere. More frequent replacement may be necessary when
to zero spacing. Proceed very carefully to avoid damaging the
testingsphere-to-sphere.Sphereelectrodesmaybecleanedand
point.Thepointofcontactshallbeestablishedelectricallywith
polished for reuse in point-to-sphere testing. However, the use
anohmmeter.Openthegaptothespecifiedspacingusingadial
of polished spheres is not recommended for sphere-to-sphere
micrometer or other suitable method.
6.1.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.