ASTM D887-02 用圆盘电极测定绝缘液体介电击穿电压的标准试验方法Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes

ASTM D887-02 用圆盘电极测定绝缘液体介电击穿电压的标准试验方法Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes

Standard Test Method for
Dielectric Breakdown Voltage of Insulating Liquids Using
Disk Electrodes1
This standard is issued under the fixed designation D 877; 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.
This standard has been approved for use by agencies of the Department of Defense.
e1
NOTE—A section reference in 11.2 was corrected editorially in February 2004.

1. Scope
1.1 This test method describes two procedures, A and B, for
determining the electrical breakdown voltage of insulating
liquid specimens. The breakdown test uses ac voltage in the
power-frequency range from 45 to 65 Hz.
1.2 This test method is used to judge if the disk electrode
breakdown voltage requirements are met for insulating liquids,
as delivered from the manufacturer, that have never been
filtered or dried. See Specification D 3487, Specification
D 4652, and Guide D 5222 for the minimum specified electri-
cal breakdown. This test method should be used as recom-
mended by professional organization standards such as IEEE
C57.106.
1.3 Limitations of the Procedures:
1.3.1 The sensitivity of this test method to the general
population of contaminants present in a liquid sample de-
creases as applied test voltages used in this test method become
greater than approximately 25 kV rms.
1.3.2 If the concentration of water in the sample at room
temperature is less than 60 % of saturation, the sensitivity of
this test method to the presence of water is decreased. For
further information refer to RR: D27-1006.
2
1.3.3 The suitability for this test method has not been
determined for a liquid’s viscosity higher than 900 cSt at 40°C.
1.4 Procedure Applications
1.4.1 Procedure A:
1.4.1.1 Procedure A is used to determine the breakdown
voltage of liquids in which any insoluble breakdown products
easily settle during the interval between the required repeated
breakdown tests. These liquids include petroleum oils, hydro-
carbons, and askarels (PCB) used as insulating and cooling
liquids in transformers, cables, and similar apparatus.
1.4.1.2 Procedure A may be used to obtain the dielectric
breakdown of silicone fluid as specified in Test Methods
D 2225, provided the discharge energy into the sample is less
than 20 mJ (milli joule) per breakdown for five consecutive
breakdowns.
1.4.2 Procedure B:
1.4.2.1 This procedure is used to determine the breakdown
voltage of liquids in which any insoluble breakdown products
do not completely settle from the space between the disks
during the 1–min interval required in Procedure A. Procedure
B, modified in accordance with Section 17 of Test Methods
D 2225, is acceptable for testing silicone dielectric liquids if
the requirements of 1.4.1.2 can not be achieved.
1.4.2.2 Procedure B should also be applied for the determi-
nation of the breakdown voltage of liquid samples containing
insoluble materials that settle from the specimen during testing.
These may include samples taken from circuit breakers, load
tap changers, and other liquids heavily contaminated with
insoluble particulate material. These examples represent
samples that may have large differences between replicate
tests. The use of Procedure B will result in a more accurate
value of breakdown voltage when testing such liquids.
1.4.2.3 Use Procedure B to establish the breakdown voltage
of an insulating liquid where an ASTM specification does not
exist or when developing a value for an ASTM guide or
standard. Procedure A may be used once the single operator
precision of 13.1 has been demonstrated.
1.5 Both the SI and inch-pound units are equally acceptable.
1
This test method is under the jurisdiction of ASTM Committee D27 on
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
mittee D27.05 on Electrical Test.
Current edition approved Oct. 10, 2002. Published December 2002. Originally
approved in 1946. Last previous edition D 877–87 (1995).
2
RR: D27–1006, Round-Robin Data Using Modified VDE Electrode Cell for
Dielectric Strength Tests on Oil, is available from ASTM Headquarters.
1
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