Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.

Abstract: The present invention comprises a mixture of hydrocarbons having a well-defined chemical composition that is suitable for use as a dielectric coolant in electrical equipment in general, and specifically in transformers. The dielectric coolants of the present invention are particularly suited for use in sealed, non-vented transformers, and have improved performance characteristics, including decreased degradation of the paper insulating layers, as well as a greater degree of safety and environmental acceptability. The present dielectric coolants comprise relatively pure blends of compounds selected from the group consisting of aromatic hydrocarbons, polyalphaolefins, polyol esters, and natural vegetable oils, along with additives to improve pour point, increase stability and reduce oxidation rate.

Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.

Abstract: A dielectric fluid with improved performance in capacitors contains 65% by weight or more monobenzyltoluene. Capacitors including the dielectric fluid can have improved discharge extinction voltages at 60° C.

Abstract: A dielectric fluid with improved performance in capacitors contains 65% by weight or more monobenzyltoluene. Capacitors including the dielectric fluid can have improved discharge extinction voltages at 60° C.

Abstract: The present invention comprises a mixture of hydrocarbons having a well-defined chemical composition that is suitable for use as a dielectric coolant in electrical equipment in general, and specifically in transformers. The dielectric coolants of the present invention are particularly suited for use in sealed, non-vented transformers, and have improved performance characteristics, including decreased degradation of the paper insulating layers, as well as a greater degree of safety and environmental acceptability. The present dielectric coolants comprise relatively pure blends of compounds selected from the group consisting of aromatic hydrocarbons, polyalphaolefins, polyol esters, and natural vegetable oils, along with additives to improve pour point, increase stability and reduce oxidation rate.

Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.

Abstract: In one aspect, the present invention provides a dielectric fluid for use in electrical equipment comprising a vegetable oil or vegetable oil blend. In another aspect the invention provides devices for generating and distributing electrical energy that incorporate a dielectric fluid comprising a vegetable oil or vegetable oil blend. Methods of retrofilling electrical equipment with vegetable oil based dielectric fluids also are provided.

Abstract: A dielectric fluid system for use in electrical equipment comprising a dielectric fluid comprising vegetable oil and an oxidation reducing composition encased in a housing composed of a polymeric material that is substantially permeable to oxygen. The oxidation reducing composition is placed inside the electrical equipment such that it is in contact with a headspace defined by the dielectric fluid. Devices generating and distributing electrical energy incorporating the above-described dielectric fluid system and method of retrofilling such devices also are provided.

Abstract: A transformer is disclosed, including a tank housing a transformer core/coil assembly, a dielectric insulating fluid surrounding the core/coil assembly, the fluid comprising a vegetable oil, an antioxidant dissolved in the oil, and a low temperature additive blended into the oil, wherein the fluid defines a headspace above the fluid. The preferred embodiment includes an oxygen absorbing material contained in the tank and in contact with gases in the tank but isolated from contact with the dielectric fluid, the tank including an opening and a sealed plug in the opening, such that the oxygen absorbing material can be replaced through the opening upon removal of the sealed plug, and further includes a gas permeable polymer container sealed against the opening for supporting the oxygen absorbing material and an indicator in gas contact with the headspace and visible from outside the tank for indicating the presence of oxygen in the headspace.

Abstract: A transformer is disclosed, including a tank housing a transformer core/coil assembly, a dielectric insulating fluid surrounding the core/coil assembly, the fluid comprising a vegetable oil, an antioxidant dissolved in the oil, and a low temperature additive blended into the oil, wherein the fluid defines a headspace above the fluid. The preferred embodiment includes an oxygen absorbing material contained in the tank and in contact with gases in the tank but isolated from contact with the dielectric fluid, the tank including an opening and a sealed plug in the opening, such that the oxygen absorbing material can be replaced through the opening upon removal of the sealed plug, and further includes a gas permeable polymer container sealed against the opening for supporting the oxygen absorbing material and an indicator in gas contact with the headspace and visible from outside the tank for indicating the presence of oxygen in the headspace.

Abstract: The present invention comprises a mixture of hydrocarbons having a well-defined chemical composition that is suitable for use as a dielectric coolant in electrical equipment in general, and specifically in transformers. The dielectric coolants of the present invention are particularly suited for use in sealed, non-vented transformers, and have improved performance characteristics, including decreased degradation of the paper insulating layers, as well as a greater degree of safety and environmental acceptability. The present dielectric coolants comprise relatively pure blends of compounds selected from the group consisting of aromatic hydrocarbons, polyalphaolefins, polyol esters, and natural vegetable oils, along with additives to improve pour point, increase stability and reduce oxidation rate.

Abstract: An electrical apparatus, such as a transformer, includes an expandable internal chamber that is nonventing and completely and permanently sealed from the ambient environment. The chamber houses a core and coil assembly or other current-carrying conductor and is completely filled with dielectric fluid having a pressure less than one atmosphere. The enclosure walls are flexible and are permitted to bow inwardly and outwardly as the volume of the dielectric fluid changes due to thermal expansion and contraction. A method of processing the dielectric fluid and filling and sealing the transformer at sub-atmospheric pressure is also disclosed.

Abstract: A composition for an insulating collar of a metal oxide varistor, with the composition being applied as a slurry to a green varistor in an unfired state along its periphery for enhancing the varistor's energy handling capability in a fired state, the composition having, in various combinations, a plurality of oxide compounds, including manganese dioxide, cobaltic-cobaltous oxide, nickel oxide, tin dioxide, chromic oxide, bismuth oxide, antimony trioxide, and zinc oxide. Moreover, a method of applying the slurry onto the unfired varistor and firing the coated green varistor in a single step.

Abstract: An electrical capacitor (10) having an improved dielectric system. The capacitor includes layers of metal foil (15,16) and dielectric sheet material (17) which is impregnated with a liquid dielectric composed of a mixture of phenyl xylyl ethane and phenyl tolyl methanes.

Abstract: An electrical apparatus, such as a capacitor, having an improved dielectric system. The capacitor includes alternate layers of metal foil and dielectric material which is impregnated with 1,1-bis(3,4-dimethylphenyl)ethane. The capacitor has improved corona characteristics and low dielectric losses. The liquid dielectric is biodegradable and environmentally acceptable.

Abstract: An electrical capacitor having an improved dielectric system. The capacitor includes layers of metal foil and a dielectric sheet material which is impregnated with a liquid dielectric composition composed of a mixture of methyl diphenyl ethane and a lower alkyl diphenyl.