This guide describes methods of testing and specifications for electrical insulating oils of petroleum origin intended for use in electrical cables, transformers, oil circuit breakers, and other electrical apparatus where the oils are used as insulating, or heat transfer media, or both. This guide is classified into the following categories: sampling practices, physical tests, electrical tests, chemical tests, and specifications. The test methods shall be as follows: aniline point; coefficient of thermal expansion; color; examination; flash and fire point; interfacial tension; pour point of petroleum products; refractive index; relative density; specific heat; thermal conductivity; turbidity; viscosity; dielectric breakdown voltage; dissipation factor and relative permittivity; gassing tendency; resistivity; stability under electrical discharge; acidity; carbon-type composition; compatibility with construction material; copper content; furanic compounds; gas analysis; gas content; inorganic chlorides and sulfates; neutralization numbers; oxidation inhibitor content; oxidation stability; polychlorinated biphenyl content; sediment and soluble sludge; sulfur; water content; mineral insulating oil for electrical apparatus; and high firepoint electrical insulating oils.

1.1 This guide describes methods of testing and specifications for electrical insulating liquids intended for use in electrical cables, transformers, liquid-filled circuit breakers, and other electrical apparatus where the liquids are used as insulating, or heat transfer media, or both.

1.2 The purpose of this guide is to outline the applicability of the available test methods. Where more than one is available for measuring a given property, their relative advantages are described, along with an indication of laboratory convenience, precision, (95 % confidence limits), and applicability to specific types of electrical insulating liquids.

1.3 This guide is classified into the following categories: Sampling Practices, Physical Tests, Electrical Tests, Chemical Tests, and Specifications. Within each test category, the test methods are listed alphabetically by property measured. A list of standards follows:

Category

Section

ASTM Standard

Sampling:

 3

D923

Physical Tests:

 Aniline Point

 4

D611

 Coefficient of Thermal Ex-
  pansion

 5

D1903

 Color

 6

D1500

 Examination: Visual Infrared

 7

D1524, D2144, D2129

 Flash and Fire Point

 8

D92

 Interfacial Tension

 9

D971

 Pour Point of Petroleum
  Products

10

D97, D5949, D5950

 Particle Count in Mineral
  Insulating Oil

11

D6786

 Refractive Index and Specific
  Optical Dispersion

12

D1218

 Relative Density (Specific
  Gravity)

13

D287, D1217, D1298, D1481, D4052

 Specific Heat

14

D2766

 Thermal Conductivity

15

D2717

 Viscosity

16

D445, D2161, D7042

Electrical Tests:

 Dielectric Breakdown Voltage

17

D877, D1816, D3300

 Dissipation Factor and Rela-
  tive Permittivity (Dielectric
   Constant)

18

D924

Gassing Characteristic
  Under Thermal Stress

19

D7150

 Gassing Tendency

20

D2300

 Resistivity

21

D1169

Chemical Tests:

 Acidity, Approximate

22

D1534

 Carbon-Type Composition

23

D2140

 Compatibility with Construc-
  tion Material

24

D3455

 Copper Content

25

D3635

 Elements by Inductively
  Coupled Plasma (ICP-AES)

26

D7151

 Furanic Compounds in
  Electrical Insulating Liquids

27

D5837

 Dissolved Gas Analysis

28

D3612

 Gas Content of Cable and
  Capacitor Liquids

29

D831, D1827, D2945

 Neutralization (Acid and
  Base) Numbers

30

D664, D974

 Oxidation Inhibitor Content

31

D2668, D4768

 Oxidation Stability

32

D1934, D2112, D2440

 Polychlorinated Biphenyl
  Content (PCB)

33

D4059

 Sulfur, Corrosive

34

D1275

 Water Content

35

D1533

Specification:

 Mineral Insulating Liquid for
  Electrical Apparatus

36

D3487

 Less Flammable Electrical
  Insulating Liquids

37

D5222

 Silicone Fluid used for Electrical
  Insulation

38

D4652

 Natural (Vegetable Oil) Ester
   Fluids used in Electrical
  Apparatus

39

D6871

1.4 The values stated in SI units are to be regarded as standard. The values stated in parentheses are provided for information only.

1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.