ASTM D 8240 : 2022

1.1This specification covers less-flammable (high fire point) synthetic ester insulating liquids for use as a dielectric and cooling in new and existing electrical power apparatus including power and distribution transformers, switchgear, and other associated equipment

1.2Synthetic ester insulating liquids differ from conventional mineral oil and other less-flammable (high fire point) liquids in that they are products derived from the chemical reaction, processing, and physical treatments of a carboxylic acid and an alcohol.

1.3This specification is intended to define synthetic ester electrical insulating liquids that are compatible with typical materials of construction of existing apparatus and are expected to maintain their functional characteristics in these applications. The material described in this specification is not always miscible with other electrical insulating liquids. The user should contact the manufacturer of the synthetic ester insulating liquid for guidance in this respect.

1.4This specification applies only to unused synthetic ester insulating liquids as received prior to any processing. The user should contact the manufacturer of the equipment or liquid, or both, if questions of recommended characteristics or liquid maintenance procedures arise.

1.5The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6This 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.

1.7This 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.