Abstract: A current-limiting fuse for use at voltages between 23 kilovolts (kV) and 38 kV includes a body including a sidewall that at least partially defines an interior space; a fuse element in the interior space of the body, the fuse element wrapped around a non-conductive core and connected to first and second electrically conductive plates; and a non-bound particulate material in the interior space of the body, the non-bound particulate material including a plurality of pieces of the material with voids between at least some of the pieces. A fuse holder for use at voltages between 23 kV and 38 kV includes a housing for insertion in a sidewall of a transformer. The housing includes an exterior surface that defines an interior region. A fuse assembly is received in the interior region of the housing, the fuse assembly being configured to be replaced without opening the tank of the transformer.

Abstract: A current-limiting fuse for use at voltages between 23 kilovolts (kV) and 38 kV includes a body including a sidewall that at least partially defines an interior space; a fuse element in the interior space of the body, the fuse element wrapped around a non-conductive core and connected to first and second electrically conductive plates; and a non-bound particulate material in the interior space of the body, the non-bound particulate material including a plurality of pieces of the material with voids between at least some of the pieces. A fuse holder for use at voltages between 23 kV and 38 kV includes a housing for insertion in a sidewall of a transformer. The housing includes an exterior surface that defines an interior region. A fuse assembly is received in the interior region of the housing, the fuse assembly being configured to be replaced without opening the tank of the transformer.

Abstract: A dielectric fluid that provides improved resistance to device failure in capacitors comprising combinations of certain anthraquinone compounds and scavengers. Capacitors including the dielectric fluid can have a higher discharge inception voltage and can have increased failure threshold voltages in comparison to capacitors made without the combination. Therefore, these capacitors are more resistant to failures.

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: 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.