A medium or high voltage electrical device and method of maintaining the composition of an insulating gas mixture in a medium or high voltage electrical device, where the device comprises a sealed chamber, said sealed chamber comprising electrical components; a gas mixture ensuring electrical insulation and/or extinguishing of electrical arcs produced in this chamber, wherein the gas mixture comprises at least one insulating gas and at least one dilution gas; and a receptacle, said receptacle comprising an opening, at least one wall, wherein at least one wall is a heatable wall, and wherein said receptacle is positioned to receive liquefied gas; the device further comprising a heating element for heating the heatable receptacle wall; and a dielectrically and thermally insulating layer located between the heatable receptacle wall and the chamber.

A sulfur hexafluoride (SF6) insulated circuit breaker system having a controller coupled to at least two different sensor devices and operative to control a heat output of an SF6 heater based on signals from the sensor devices. An SF6 insulated circuit breaker system includes a controller coupled to a circuit breaker position indicator and operative to control an SF6 heater based on a signal from the contact position indicator sensor. An SF6 insulated circuit breaker system has a controller coupled to an SF6 density monitor and operative to control an SF6 heater based on a signal from the SF6 density monitor.

An enclosure of a circuit breaker that includes an interior region and a pass-through. The interior region can be sized to house a circuit interrupter and a dielectric insulating medium. The pass-through can include a pathway having a first open end and a second open end, the first and second open ends being in direct fluid communication with each other through the pathway. The first and second open ends can be secured to the enclosure such that the pass-through is integral to the enclosure, such as, for example, being part of a monolithic structure or constructed to form a unitary body. Additionally, the pathway may not be in direct fluid communication with the interior region of the enclosure. Further, the pass-through can be offset from, or extend directly into, the interior region of the enclosure.

An enclosure of a circuit breaker that includes an interior region and a pass-through. The interior region can be sized to house a circuit interrupter and a dielectric insulating medium. The pass-through can include a pathway having a first open end and a second open end, the first and second open ends being in direct fluid communication with each other through the pathway. The first and second open ends can be secured to the enclosure such that the pass-through is integral to the enclosure, such as, for example, being part of a monolithic structure or constructed to form a unitary body. Additionally, the pathway may not be in direct fluid communication with the interior region of the enclosure. Further, the pass-through can be offset from, or extend directly into, the interior region of the enclosure.

A method of distributing an electrically insulating liquefied gas mixture to high-voltage electrical equipment from a storage means containing an insulating gas mixture, including: heating the insulating gas mixture to a temperature such that the contents of the storage means are a homogeneous fluid; and withdrawing the insulating mixture resulting from step a) to fill high-voltage electrical equipment by raising the temperature of the mixture resulting from step a), wherein, during step b), a set value for regulation is applied at variable pressure, calculated in real time based on weighing the storage means, when the change in the set value of pressure is less than 0.2 bar per 1 kg/m.sup.3 of change in density, and then a set value for regulation is applied at constant temperature until the storage means is emptied of its content.

An apparatus for heating an insulation fluid in a medium-voltage or high-voltage switchgear comprises an infrared source which is adapted to emit infrared radiation of at least one wavelength. Thus, at least one vibrational or rotational mode of at least one component of the insulation fluid is excited by absorption of at least a part of the infrared radiation, and condensation of the insulation fluid is efficiently prevented by this direct heating of the insulation fluid. A closed loop temperature regulator is used to heat only when required. A circulator in a heating chamber further provides for a mixing of the insulation fluid, thus preventing steep temperature gradients.

A method and a facility for filling a high- or medium-voltage gas-insulated electrical apparatus in which the insulating gas comprises a mixture of heptafluoroisobutyronitrile ((CF.sub.3).sub.2CFCN) and carbon dioxide. The method and the facility using a mixture of (CF.sub.3).sub.2CFCN and CO.sub.2 in pressurised liquid form which is heated to a temperature no lower than the critical temperature of the mixture.

A medium or high voltage electrical device and method of maintaining the composition of an insulating gas mixture in a medium or high voltage electrical device, where the device comprises a sealed chamber, said sealed chamber comprising electrical components; a gas mixture ensuring electrical insulation and/or extinguishing of electrical arcs produced in this chamber, wherein the gas mixture comprises at least one insulating gas and at least one dilution gas; and a receptacle, said receptacle comprising an opening, at least one wall, wherein at least one wall is a heatable wall, and wherein said receptacle is positioned to receive liquefied gas; the device further comprising a heating element for heating the heatable receptacle wall; and a dielectrically and thermally insulating layer located between the heatable receptacle wall and the chamber.

A method of distributing an electrically insulating liquefied gas mixture to high-voltage electrical equipment from a storage means containing an insulating gas mixture, including: heating the insulating gas mixture to a temperature such that the contents of the storage means are a homogeneous fluid; and withdrawing the insulating mixture resulting from step a) to fill high-voltage electrical equipment by raising the temperature of the mixture resulting from step a), wherein, during step b), a set value for regulation is applied at variable pressure, calculated in real time based on weighing the storage means, when the change in the set value of pressure is less than 0.2 bar per 1 kg/m.sup.3 of change in density, and then a set value for regulation is applied at constant temperature until the storage means is emptied of its content.

The invention relates to a method for drying a chamber comprising a predominantly protective-gas atmosphere in the chamber under positive pressure, which has an operating pressure p1 and a predetermined minimum pressure p.sub.min, wherein the minimum pressure p.sub.min of the gas chamber is monitored and the operating pressure p1 is greater than the minimum pressure p.sub.min, wherein the method comprises the following steps: a) removing of a partial quantity Vi of the protective gas from the chamber, wherein the partial quantity Vi is equivalent to the pressure differential p, which is smaller or equal to the differential between p1 and p.sub.min, b) introducing a partial quantity V2 of a dry or dried protective gas into the gas chamber up to a gas pressure p2, which is greater than p.sub.min and c) repeating method steps a) and b) after a predetermined waiting time t. The invention further relates to an arrangement for carrying out the method.