ASTM D3487-88(1993)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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 3487 – 88 (Reapproved 1993)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Specification for
Mineral Insulating Oil Used in Electrical Apparatus
This standard is issued under the fixed designation D 3487; 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.
1. Scope D 971 Test Method for Interfacial Tension of Oil Against
Water by the Ring Method
1.1 This specification covers new mineral insulating oil of
D 974 Test Method for Acid and Base Number by Color-
petroleum origin for use as an insulating and cooling medium
4 5
Indicator Titration ,
in new and existing power and distribution electrical apparatus,
D 1275 Test Method for Corrosive Sulfur in Electrical
such as, transformers, regulators, reactors, circuit breakers,
Insulating Oils
switchgear, and attendant equipment.
D 1298 Practice for Density, Relative Density (Specific
1.2 This specification is intended to define a mineral insu-
Gravity), or API Gravity of Crude Petroleum and Liquid
lating oil that is functionally interchangeable and miscible with
Petroleum Products by Hydrometer Method
existing oils, is compatible with existing apparatus and with
2 D 1473 Test Method for 2,6-Ditertiary-Butyl Para-Cresol in
appropriate field maintenance, and will satisfactorily main-
Electrical Insulating Oils
tain its functional characteristics in its application in electrical
D 1500 Test Method for ASTM Color of Petroleum Prod-
equipment. This specification applies only to new insulating oil
ucts (ASTM Color Scale)
as received prior to any processing.
D 1524 Test Method for Visual Examination of Used Elec-
2. Referenced Documents
trical Insulating Oils of Petroleum Origin in the Field
D 1533 Test Methods for Water in Insulating Liquids (Karl
2.1 ASTM Standards:
Fischer Reaction Method)
D 88 Test Method for Saybolt Viscosity
D 1816 Test Method for Dielectric Breakdown Voltage of
D 92 Test Method for Flash and Fire Points by Cleveland
Insulating Oils of Petroleum Origin Using VDE Elec-
Open Cup
trodes
D 97 Test Method for Pour Point of Petroleum Products
D 1903 Test Method for Coefficient of Thermal Expansion
D 445 Test Method for Kinematic Viscosity of Transparent
of Electrical Insulating Liquids of Petroleum Origin, and
and Opaque Liquids (and the Calculation of Dynamic
Askarels
Viscosity)
D 2112 Test Method for Oxidation Stability of Inhibited
D 611 Test Methods for Aniline Point and Mixed Aniline
Mineral Insulating Oil by Rotating Bomb
Point of Petroleum Products and Hydrocarbon Solvents
D 2300 Test Method for Gassing of Insulating Oils Under
D 877 Test Method for Dielectric Breakdown Voltage of
Electrical Stress and Ionization (Modified Pirelli
Insulating Liquids Using Disk Electrodes
Method)
D 923 Test Method for Sampling Electrical Insulating Liq-
D 2440 Test Method for Oxidation Stability of Mineral
uids
Insulating Oil
D 924 Test Method for Dissipation Factor (or Power Factor)
D 2668 Test Method for 2,6-Ditertiary-Butyl Para-Cresol
and Relative Permittivity (Dielectric Constant) of Electri-
and 2,6-Ditertiary-Butyl Phenol in Electrical Insulating Oil
cal Insulating Liquids
by Infrared Absorption
D 2717 Test Method for Thermal Conductivity of Liquids
This specification is under the jurisdiction of ASTM Committee D-27 on
D 2766 Test Method for Specific Heat of Liquids and
Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-
Solids
mittee D27.01on Mineral Oils.
D 3300 Test Method for Dielectric Breakdown Voltage of
Current edition approved May 12, 1988. Published August 1988. Originally
published as D3487 – 76. Last previous edition D3487 – 82a.
Insulating Oils of Petroleum Origin Under Impulse Con-
Refer to American National Standard C 59.131. Guide for Acceptance and
ditions
Maintenance of Insulating Oil in Equipment (IEEE Standard 64). Available from the
American National Standards Institute, 11 West 42nd Street, 13th Floor, New York,
NY 10036.
Annual Book of ASTM Standards, Vol 04.04.
4 6
Annual Book of ASTM Standards, Vol 05.01. Discontinued; see 1987 Annual Book of ASTM Standards, Vol 10.03.
5 7
Annual Book of ASTM Standards, Vol 10.03. Annual Book of ASTM Standards, Vol 05.02.
D 3487
D 4059 Test Method for Analysis of Polychlorinated Biphe- 3.3 additives—chemical substances that are added to min-
nyls in Insulating Liquids by Gas Chromatography eral insulating oil to achieve required functional properties.
3.4 properties—those properties of the mineral insulating
3. Terminology Definitions
oil which are required for the design, manufacture, and
operation of the apparatus. These properties are listed in
3.1 Type I Mineral Oil—an oil for apparatus where normal
Section 5.
oxidation resistance is required. Some oils may require the
addition of a suitable oxidation inhibitor to achieve this.
4. Sampling and Testing
3.2 Type II Mineral Oil—an oil for apparatus where greater
oxidation resistance is required. This is usually achieved with
4.1 Take all oil samples in accordance with Test Methods
the addition of a suitable oxidation inhibitor.
D 923.
4.2 Make each test in accordance with the latest revision of
NOTE 1—During processing of inhibited mineral oil under vacuum and
elevated temperatures, partial loss of inhibitor and volatile portions of the ASTM test method specified in Section 5.
mineral oil may occur. The common inhibitors, 2,6-ditertiary-butyl
4.3 The oil shall meet the requirements of Section 5 at the
para-cresol and 2,6-ditertiary-butyl phenol, are more volatile than trans-
unloading point.
former oil. If processing conditions are too severe, oxidation stability of
the oil may be decreased due to loss of inhibitor. The selectivity for
NOTE 2—Because of the different needs of the various users, items
removal of moisture and air in preference to loss of inhibitor and oil is
relating to packaging, labeling, and inspection are considered to be subject
improved by use of a low processing temperature.
to buyer-seller agreement.
Conditions that have been found satisfactory for most inhibited mineral
NOTE 3—In addition to all other tests listed herein, it is sound
oil processing are:
engineering practice for the apparatus manufacturer to perform an
Minimum Pressure evaluation of new types of insulating oils in insulation systems, prototype
Temperature, °C Pa Torr, Approximate
structures, or full-scale apparatus, or any combination thereof, to assure
40 5 0.04
suitable service life.
50 10 0.075
60 20 0.15
4.4 Make known to the user the generic type and amount of
70 40 0.3
any additive used, for assessing any potential detrimental
80 100 0.75
reaction with other materials in contact with the oil.
90 400 3.0
100 1000 7.5
5. Property Requirements
If temperatures higher than those recommended for the operating
pressure are used, the oil should be tested for inhibitor content and
5.1 Mineral insulating oil conforming to this specification
inhibitor added as necessary to return inhibitor content to its initial value.
shall meet the property limits given in Table 1. The significance
Attempts to dry apparatus containing appreciable amounts of free water
of these properties is discussed in Appendix X2.
may result in a significant loss of inhibitor even at the conditions
recommended above.
D 3487
TABLE 1 Property Requirements
Limit ASTM Test
Property
Method
Type I Type II
Physical:
A A
Aniline point, °C (63–84) (63–84) D611
Color, max 0.5 0.5 D 1500
Flash point, min, °C 145 145 D 92
Interfacial tension at 25°C, min, dynes/cm 40 40 D 971
B B
Pour point, max, °C −40 −40 D97
Specific gravity, 15°C/15°C max 0.91 0.91 D 1298
Viscosity, max, cSt (SUS) at:
C C
100°C 3.0 (36) 3.0 (36) D 445 or D 88
C C
40°C 12.0 (66) 12.0 (66)
0°C 76.0 (350) 76.0 (350)
Visual examination clear and bright clear and bright D 1524
Electrical:
Dielectric breakdown voltage at 60 Hz:
Disk electrodes, min, kV 30 30 D 877
D D
VDE electrodes, min, kV 0.040-in. (1.02-mm) gap 28 28 D 1816
D D
0.080-in. (2.03-mm) gap 56 56
Dielectric breakdown voltage, impulse conditions D 3300
A,E A,E
25°C, min, kV, needle negative to sphere grounded, 145 145
1-in. (25.4-mm) gap
F,G
Gassing tendency, max, μL/min + 15 +15 D 2300 (Procedure A)
+30 +30 D 2300 (Procedure B)
Dissipation factor (or power factor), at 60 Hz max, %: D 924
25°C 0.05 0.05
100°C 0.30 0.30
Chemical:
Oxidation stability (acid-sludge test) D 2440
72 h:
A
% sludge, max, by mass 0.15 0.1
A
Total acid number, max, mg KOH/g 0.5 0.3
164 h:
A
% sludge, max, by mass 0.3 0.2
A
Total acid number, max, mg KOH/g 0.6 0.4
Oxidation stability (rotating bomb test), min, minutes — 195 D 2112
H
Oxidation inhibitor content, max, % by mass 0.08 0.3 D 1473 or D 2668
Corrosive sulfur noncorrosive D 1275
Water, max, ppm 35 35 D 1533
Neutralization number, total acid number, max, mg 0.03 0.03 D 974
KOH/g
PCB content, ppm not detectable not detectable D 4059
A
The value shown represents current knowledge. Work is in progress to reaffirm the validity of this value.
B
In certain sections of the United States and Canada, it is common practice to specify a lower or higher pour point, depending upon climatic conditions.
C
At the temperatures previously used for insulating oil viscosity determinations, these values correspond to 3.1 cSt (36.5 SUS) at 210°F (98.9°C) and to 13.0 cSt (70
SUS) at 100°F (37.8°C).
D
These limits by Test Method D 1816 are applicable only to new oil which has been filtered, dehydrated, and degassed (see Appendix, X2.2.3).
E
Currently available oils vary in impulse strength. Some users prefer oil of a 145 kV minimum for certain applications, while others accept oil with impulse strength as
low as 130 kV for other applications.
F
Specification requires that insulating oils meet the gassing tendency limits as measured by Test Method D 2300 either Procedure A or B. The specification does not
require that insulating oils meet gassing tendency limits as measured by both Test Method D 2300 Procedures A and B.
G
In the gassing tendency test in Test Method D 2300 Procedures A and B, the test temperature should be 80°C with a test voltage of 12 kV for Procedure A and a test
voltage of 10 kV for Procedure B.
H
Both 2,6-ditertiary-butyl para-cresol and 2,6-ditertiary butylphenol have been found to be suitable oxidation inhibitors for use in oils meeting this specifica
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