ASTM International - ASTM D924-08
Standard Test Method for Dissipation Factor (or Power Factor) and Relative Permittivity (Dielectric Constant) of Electrical Insulating Liquids
|Publication Date:||1 November 2008|
|ICS Code (Insulating oils):||29.040.10|
significance And Use:
Dissipation Factor (or Power Factor)-This is a measure of the dielectric losses in an electrical insulating liquid when used in an alternating electric field and of the energy dissipated as heat.... View More
Dissipation Factor (or Power Factor)-This is a measure of the dielectric losses in an electrical insulating liquid when used in an alternating electric field and of the energy dissipated as heat. A low dissipation factor or power factor indicates low ac dielectric losses. Dissipation factor or power factor may be useful as a means of quality control, and as an indication of changes in quality resulting from contamination and deterioration in service or as a result of handling.
The loss characteristic is commonly measured in terms of dissipation factor (tangent of the loss angle) or of power factor (sine of the loss angle) and may be expressed as a decimal value or as a percentage. For decimal values up to 0.05, dissipation factor and power factor values are equal to each other within about one part in one thousand. In general, since the dissipation factor or power factor of insulating oils in good condition have decimal values below 0.005, the two measurements (terms) may be considered interchangeable.
The exact relationship between dissipation factor (D) and power factor (PF) is given by the following equations:
The reported value of D or PF may be expressed as a decimal value or as a percentage. For example:
Relative Permittivity (Dielectric Constant)-Insulating
Theory relating to dielectric measurement techniques and to sources of dielectric loss is given in Test Methods D 150.View Less
1.1 This test method describes testing of new electrical insulating liquids as well as liquids in service or subsequent to service in cables, transformers, oil circuit breakers, and other electrical apparatus.
1.2 This test method provides a procedure for making referee tests at a commercial frequency of between 45 and 65 Hz.
1.3 Where it is desired to make routine determinations requiring less accuracy, certain modifications to this test method are permitted as described in Sections 16 to 24.
1.4 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 and health practices and to determine the applicability of regulatory limitations prior to use. Specific warnings are given in 11.3.3.
1.5 Mercury has been designated by the EPA and many state agencies as a hazardous material that can cause nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and the EPA's website: http://www.epa.gov/m