A cable that includes a conductor defining a hollow interior, a casing surrounding the conductor, an electrical insulator positioned between the conductor and the casing, and a fluid positioned within the hollow interior of the conductor.

A cable that includes a conductor defining a hollow interior, a casing surrounding the conductor, an electrical insulator positioned between the conductor and the casing, and a fluid positioned within the hollow interior of the conductor.

A cable includes an inner conductor and a dielectric layer extending around the inner conductor. The dielectric layer includes a linearly-stretched polypropylene film having a porous structure that includes a plurality of pores that extend through a thickness of the linearly-stretched polypropylene film. The dielectric layer includes air molecules trapped within the pores of the linearly-stretched polypropylene film such that the dielectric layer includes polypropylene and air. The cable includes an outer conductor extending around the dielectric layer.

A method can include extruding an electrically insulating elastomeric compound about a conductor where the electrically insulating elastomeric compound includes ethylene propylene diene monomer (M-class) rubber (EPDM) and an alkane-based peroxide that generates radicals that form decomposition products; cross-linking the EPDM via radical polymerization to form an electrically insulating layer about the conductor; heating the cross-linked EPDM to at least 55 degrees C. to reduce the concentration of the decomposition products in the electrically insulating layer; and disposing a gas barrier layer about the electrically insulating layer.

A method can include extruding an electrically insulating elastomeric compound about a conductor where the electrically insulating elastomeric compound includes ethylene propylene diene monomer (M-class) rubber (EPDM) and an alkane-based peroxide that generates radicals that form decomposition products; cross-linking the EPDM via radical polymerization to form an electrically insulating layer about the conductor; heating the cross-linked EPDM to at least 55 degrees C. to reduce the concentration of the decomposition products in the electrically insulating layer; and disposing a gas barrier layer about the electrically insulating layer.

A method can include extruding an electrically insulating elastomeric compound about a conductor where the electrically insulating elastomeric compound includes ethylene propylene diene monomer (M-class) rubber (EPDM) and an alkane-based peroxide that generates radicals that form decomposition products; cross-linking the EPDM via radical polymerization to form an electrically insulating layer about the conductor; heating the cross-linked EPDM to at least 55 degrees C. to reduce the concentration of the decomposition products in the electrically insulating layer; and disposing a gas barrier layer about the electrically insulating layer.

A method can include extruding an electrically insulating elastomeric compound about a conductor where the electrically insulating elastomeric compound includes ethylene propylene diene monomer (M-class) rubber (EPDM) and an alkane-based peroxide that generates radicals that form decomposition products; cross-linking the EPDM via radical polymerization to form an electrically insulating layer about the conductor; heating the cross-linked EPDM to at least 55 degrees C. to reduce the concentration of the decomposition products in the electrically insulating layer; and disposing a gas barrier layer about the electrically insulating layer.

A dielectric material with heat transfer properties includes a first fluid and a second fluid different from the first fluid and miscible with the first fluid. The first fluid and the second fluid are mixed with each other so as to form a mixture and are kept at a temperature and a pressure so that the mixture is maintained in a supercritical phase. The mixture has at least one parameter that is preferably different from a corresponding parameter in both a supercritical phase of the first fluid and a supercritical phase of the second fluid. In a method of insulating electrical contacts and removing heat therefrom, the mixture is disposed about the electrical contacts and is maintained at a temperature and at a pressure that causes the mixture to be in a supercritical phase so that the mixture has favorable dielectric and heat transfer properties.

A dielectric material with heat transfer properties includes a first fluid and a second fluid different from the first fluid and miscible with the first fluid. The first fluid and the second fluid are mixed with each other so as to form a mixture and are kept at a temperature and a pressure so that the mixture is maintained in a supercritical phase. The mixture has at least one parameter that is preferably different from a corresponding parameter in both a supercritical phase of the first fluid and a supercritical phase of the second fluid. In a method of insulating electrical contacts and removing heat therefrom, the mixture is disposed about the electrical contacts and is maintained at a temperature and at a pressure that causes the mixture to be in a supercritical phase so that the mixture has favorable dielectric and heat transfer properties.

A gas mixture including at least a fluorinated nitrile, carbon dioxide and oxygen for use in electrical equipment is provided. The percentage of oxygen may be at least twice the percentage of the fluorinated nitrile. An additive gas may be present in the gas mixture. A switchgear unit having a gas-insulated compartment including a gas mixture including at least a fluorinated nitrile, carbon dioxide and oxygen is also provided. The percentage of oxygen may be at least twice the percentage of the fluorinated nitrile. An additive gas may be present in the gas mixture housed in the gas-insulated compartment.