Abstract: A bushing wherein the voltage stress across the surface of the bushing is alleviated by placement of a layer of insulating material in direct contact with the surface. The insulating material is preferably a high-voltage type, heat-shrinkable, halogen-free polyolefin, and is preferably fully shrunk to conform to the contours of the outer surface of the bushing.

Abstract: A head type current transformer having an aluminum head housing mounted on top of and supported by a porcelain insulator. The head housing and insulator together define an enclosure housing therein an, insulated, electrical component immersed in a liquid dielectric. The transformer unit is rendered explosion resistant by having a shock wave attenuator located at least partially in the liquid in the vicinity of the juncture of the housing and insulator to reduce the force of a shock wave originating in the head housing below that which would cause fracturing of the porcelain insulator. A selected area of the wall of the head housing is also patterned to facilitate its rupture in a predetermined area which is in the region of the highest voltage stress area. A filler material of felt is also used to displace a portion of the oil dielectric at the area of weakness.

Abstract: A corrona test set has at least a reactor and power separation filter placed in an oil-filled conductive tank of a conductive material such as sheet steel. The exciter optionally may also be placed in the same tank enclosure which is of much smaller size than the equivalent voltage rating test set in air. High voltage taken from the circuit passes out of the tank through high voltage bushings. A preferred form of bushing is a quick coupling cable receiving device having an insulator extending into the tank and a frustoconical metallic extension extending away from the tank with a tubular internal wall connected to these respective parts at opposite ends to form a further oil-filled compartment separate from the tank.

Abstract: A feedthrough bushing for a high voltage diode provides for using compression sealing for all sealing surfaces. A diode assembly includes a central conductor extending through the bushing and a grading ring assembly circumferentially surrounding and coaxial with the central conductor. A flexible conductive plate extends between and compressively seals against the central conductor and the grading ring assembly, wherein the flexibility of the plate allows inner and outer portions of the plate to axially translate for compression sealing against the central conductor and the grading ring assembly, respectively. The inner portion of the plate is bolted to the central conductor for affecting sealing. A compression beam is also bolted to the central conductor and engages the outer portion of the plate to urge the outer portion toward the grading ring assembly to obtain compression sealing therebetween.

Abstract: A transformer of the type used to produce high voltage for an electrostatic field apparatus has a hermetically sealed container. The container encloses a coil assembly having primary and secondary coils wound on a common core. Electrical terminals extend outward from the container and are connected to the coils. The interior volume of the container is completely filled with a thermally conductive, electrically non-conducting fluid. The internal pressure of the transformer is less than one atmosphere at 22.degree. C. The transformer can be operated in any mounting orientation of its rated power. A method of manufacturing the transformer is described by which gases are removed from the container so that it can be completely filled with the fluid.

Abstract: A cylinder is flanged onto the wall of a vacuum chamber in which a workpiece is to be coated and is to brought into contact with a current or power conductor for accomplishing same, and the current conductor in the form of a piston rod extends through this cylinder. The piston rod includes at one end a disk of graphite intended to contact the workpiece. An annular piston which is rigidly mounted on the piston rod is subjected at its outer side to the atmospheric pressure and closes a space off located within the cylinder and enclosed by a bellows, which space communicates with the vacuum chamber. A spiral pressure spring within the cylinder which rests against its bottom and against the inner side of the piston counteracts the atmospheric pressure at the outer side of the piston. In case of a subatmospheric pressure in the space, the piston is moved inwards into the cylinder against the action of the spring and the contact between the current conductor and the workpiece is established automatically.

Abstract: An electrical apparatus with an in-tank shield has a tank which houses an electrical device such as a transformer. A plurality of bushings extend into the tank. Inner shields having good electrical conductivity surround the inner portions of the bushings and are connected to the outer portions of the bushings. A shorting plate having a good electrical conductivity connects the inner shields to each other.

Abstract: A cable (1) entering a submersible machine, such as an electrically driven pump, a turbine etc., is surrounded by a collar (3) of a rigid material, and the collar (3) is secured to the machine shell (2) by bolts (4). Two sockets (5) and (6) of an elastic material surround the cable (1), one of them mounted in the shell (2) and the other in the collar (3). A ring (8) of a rigid material is arranged between the two sockets (5) and (6). The collar (3), during mounting, is moved towards and into contact with the shell (2), thereby causing the sockets (5) and (6) to be compressed axially and expanded radially so that the cable (1) is secured and sealed.

Abstract: A fluid cooled feedthrough, for conducting electrical energy at high power levels through a wall of a pressure or vacuum vessel includes a mounting flange for mounting the feedthrough to a mating flange formed at a wall of the vessel. The mounting flange includes a seal for sealing the flange to the mating flange in a high pressure/vacuum sealing arrangement. An insulator tube is secured to the mounting flange in a high pressure/vacuum sealing arrangement. A conductor tube is secured to the insulator tube at a bonding region at an outer end thereof, and the conductor tube conducts electrical energy at high power levels and carries cooling fluid therethrough. The conductor tube defines at least one interior cooling fluid flow passage directly adjacent to the bonding region for conducting away the heat generated at the region incident to the passage of the electrical energy at high power levels. The insulator tube insulates the conductor tube from the mounting flange and from the wall.

Abstract: A connector is described which can be easily installed in a hole of a barrier wall, which assures tight sealing when there is a substantial pressure difference on opposite sides of the wall, and which avoids set of the sealing material. The connector includes a frame with a radially inner portion and with a skirt extending around the inner portion and slightly bendable radially outward and inward. O-rings are mounted on the outside of the skirt, so when pressure causes the skirt to expand, the O-rings form a tight fit against the surface of the hole, while when pressure is relieved the seals are pressed with less force and avoid becoming set. A group of thin limiters extend between the skirt and the inner frame portion. The limiters allow the skirt to expand radially outwardly, but limit radially inward deflection of the skirt to assure that even when there is no pressure the O-rings push firmly against the hole surface.

Abstract: A vacuum tight electrical feedthru is disclosed for use where electrical leads must pass through the walls of a container in which a high vacuum must be maintained. It is useful in conjunction with infrared sensors, as well as for security, fire detection, rescue, night vision and medical applications. The feedthru includes a ceramic circuit ring with electrical traces deposited on one side. A ceramic seal ring partially covers the traces and is fired down to the main ceramic ring forming a hermetic seal. Metal rings are brazed to the seal ring and the ceramic circuit ring to allow welding to a housing. Spring loaded pads load a resilient pad onto the cables forcing gold plated dots to make contact to the pads on the ceramic circuit ring. This feedthru provides 180 conductors, 90 on each side. The ribbon cables are etched to expose the wires, which are then pressed on the gold dots.

Abstract: A gas insulated metal-clad electrical power equipment has a cylindrical insulating bushing for supporting an electrical conductor. The bushing is filled with the insulating gas therein and air-tightly fixed to a grounded metal compartment wall member of the equipment in such a way that the outer surface of the conductor directly faces the inner circumferential surface of a through hole formed in the wall member with a distance g therebetween. When the axial length l of the inner cylindrical space of the bushing is determined as l.gtoreq.g/4 and further the difference in diameter between the wall through hole .phi..sub.1 and the inner cylindrical space .phi..sub.2 of the bushing is determined as .phi..sub.2 -.phi..sub.1 .gtoreq.4 mm, it is possible to effectively prevent dielectric breakdown along the surface of the bushing. Owing to the above arrangement, it is possible to effectively reduce the size, space, weight, cost, etc. of the bushing, as compared with conventional ones.

Abstract: A terminal assembly (10) for a gas-filled, oil-cooled generator (14). The generator housing (12) includes an annular opening (18) with an annular boss (20) projecting into the housing (12), and sprayed coolant oil around the housing boss (20). A terminal insulator (26) is supported ion the boss (20), and a conducting lead (34) extends through an opening (32) in the terminal insulator (26). O-rings (40,42) seal the insulator (26) with both the boss (20) and the conducting lead (34). The lead (34) is resistance brazed to the end turn (56) of the generator stator.

Abstract: A pressurizable housing for an electrical apparatus which can be used in an explosive environment has a cable feedthrough connected to an electrical unit within the housing. The cable feedthrough also accommodates a passage for pressurizing the interior of the housing with a gas excluding the incursion of explosive gases into the housing.

Abstract: A superconducting-coil apparatus according to the present invention comprises a normal-fluid helium bath, a superfluid helium bath, a channel connecting the two baths, superconducting coils contained in the superfluid helium bath, current lead wires extending from an exciting current source to the superconducting coils, through the channel, and a valve plug normally closing the channel and adapted to open the channel when the pressure inside the superfluid helium bath rises above a predetermined level. If the superconducting coils undergo quenching while they are being excited, the superfluid helium is gasified by Joule heat, produced in the coils. As a result, the pressure inside the superfluid helium bath increases, so that the valve plug is urged to open the channel due to the pressure difference. The gasified helium directly cools those portions of the lead wires which pass through the channel, thus these wire portions are prevented from being burned out.

Abstract: An electrical termination comprises a cable lug 1 fitted to an end of an electric cable 3 and connected to a terminal 5 provided with an insulating bushing 6. An insulating shroud 13 comprising a rigid sleeve 14 and a removable closure element 15 fits over the terminal in spaced relationship thereto, with the space between the sleeve 14 and the bushing 6 at the end portion 19 of the sleeve 14 opposite the closure element 15 being closed by an annular insulating member 18. The sleeve and the closure element are provided with cooperating open end slots 20, 21 which define an aperture in the shroud in which a further insulating sleeve 23 fits so as to extend outwardly from the shroud. The cable lug 1 passes through the sleeve 23.

Abstract: An internally threaded insert having intersecting faces about its axis is positioned in a keyed aperture formed in a cover for a capacitor. This provides an antitwist characteristic between the insert and the walls of the aperture to facilitate a seal between the two. An electrical terminal can then be threaded into the insert to electrically connect it to an internal lead of the capacitor.An elastic bushing is also carried in the keyed aperture to provide a seal.The cover has a rib extending around its periphery to engage a capacitor housing, the rib providing a seal.

Abstract: A gland which is installed in the hole of a wall between two different atmospheres to prevent the leakage of a fluid from the one side to the other side of the wall along the outer sheath of an electric cable has a tubular metallic housing which is sealingly installed in the hole and into which the cable extends. The interior of the housing is filled with a hardened filler material which completely surrounds bare portions of conductors. Beads are formed on such bare portions. Sleeves are shrunk onto the bare portions of the conductors between the respective beads and insulators for the conductors. A tension reducing clamp surrounds the outer sheath of the cable in the housing. The aperture at one end of the housing contains an O-ring which is biased against the external surface of the outer sheath of the cable and against the surface surrounding the aperture by a second ring.

Abstract: A high voltage feed-through bushing has a conductive gasket to connect a conductive coating to a metal enclosure. A central conductor rod of the bushing is surrounded by an insulating tube which is surrounded by a tubular conductor to establish a floating equipotential surface. The central conductor rod is located within a bushing shell by sealing means at the outer and inner ends of the bushing.

Abstract: An electrical insulating and sealing apparatus, and process of using same, is described for use in an electrostatic precipitator. The apparatus employs a flexible insulator seal through which passes an electrical lead-in conductor with rubber boots to seal the insulator seal against gas leakage. Also provided are a manifold and venturi section surrounding the insulator seal to permit a pressurized gas to impinge on the insulator seal and flow downwardly over the seal through the venturi section at increased speed to help clean and keep clean the surface of the insulator seal.

Abstract: A self-sealing electrode guide for supporting an electrode in an electrode port of a welding chamber, includes a housing adapted to be mounted in the electrode port and a sealing sleeve accommodated in a housing channel defined in the housing. The sealing sleeve has opposite first and second ends and an open-ended passage adapted to receive the electrode. The first end is disposed for exposure to an external force which is oriented in a direction extending from the first end towards the second end and which is derived from a pressure in the welding chamber. An abutting arrangement is provided in the housing for cooperating with the second end to prevent displacement of the sealing sleeve relative to the housing. The sealing sleeve is resiliently deformable by the external force for assuming a deformed state in which the sealing sleeve is sealingly pressed about the electrode and against housing walls forming the housing channel.

Abstract: A piercing fluid-tight connector device for use with ultra-low temperature cable for supplying external electrical current to a motor of a pump located in an accumulation tank or vessel. An insulating sleeve having a flange with a female thread at an inner peripheral surface of the sleeve is threadingly engaged with an electrically conductive rod with a male thread thereof. A sealing member is interposed between the sleeve and rod. The coupled sleeve and rod extend through an aperture in a main metal body with the flange of the insulating sleeve and the metal body being in contact with each other, preferably through a packing, so as to provide a fluid-tight structure.

Abstract: This disclosure is concerned with a process of and apparatus for producing relatively low energy electron beams through pulsed cold-cathode beam generation in a mode of operation involving an important intermediate region of a substantially linear depth-dose profile characteristic that reduces the sensitivity to possible voltage variations, and with improved triggering structures that significantly improve reliability and minimize erratic pulse generation and missing pulses, thus particularly adapting the process and apparatus for such stringent applications as production-line sterilization of surfaces, materials or workpieces passed by the apparatus.

Abstract: The passage in a wall which separates the interior of the housing of a glandless submersible motor pump from the surrounding atmosphere is normally sealed by an annular seat which is placed against the end face of a muff forming a detachable part of the wall, and by a temperature- and pressure-resistant ceramic sleeve which surrounds an elongated metallic conductor and normally bears against the seat owing to the pressure differential between the interior of the housing and the surrounding atmosphere. If the sleeve is destroyed, a normally confined plunger of the conductor bears directly against the seat to prevent escape of fluid from the pump housing. That end portion of the conductor which extends into the housing is surrounded by one or more layers of insulating tape and by a tubular sheath which is shrunk onto the tape and exhibits at least some thermal-shock-absorbing characteristics.

Abstract: Electrical inductive apparatus for minimizing power losses in heating of a tank of an electrical inductive structure due to a magnetic field characterized by a tank having a metal wall including openings therein, electrical inductive apparatus within the tank and having terminals thereon, a bushing extending through each opening, conductor means extending through each bushing and connected to the terminals, an electrically conductive shielding member within the tank and disposed between the openings, an electrically conductive member externally of the tank, the shielding member being electrically connected to the electrically conductive member through the openings, whereby the tank is shielded from magnetic fields generated by load currents flowing through the conductor means to minimize power losses and heating of the tank wall.

Abstract: A high voltage transformer bushing having an inner conductor extending from a lower end to a point spaced from an upper end and having a side terminal at that point connected to a fuse link which is in turn connected to a high voltage line connector supported on the upper end of the bushing. A lightning arrester supported by and grounded to the transformer casing has an upper end spaced from the high voltage line connector to provide a spark gap.

Abstract: An electrical bushing is provided to facilitate the passage of electrical conductor leads from thermocouples or the like through a pressure barrier. The bushing includes a casing and a deformable, resilient, elastic plug which is disposed in a central conductor receiving bore of the casing in surrounding relationship to the conductors. Thus, when the plug is compressed in a direction axially of the casing, the plug tends to expand laterally radially and into sealing contact with the internal surfaces of the bore and with the electrical conductors.

Abstract: A conductive bushing connector includes an elongated metal stud having a center axial passage, a plurality of transverse apertures, and threaded portions at each end. A pair of insulative housings assembled on opposite sides of a transformer enclosure each overlying the metal stud and abutting the wall of the transformer enclosure form a cavity surrounding the metal stud. A pair of threaded end terminals cooperate with the threaded end portions of the metal stud to secure the entire assembly. Each interface of the assembly is provided with resilient sealing members which are maintained in compression by the end terminals. The insulative housing within the transformer enclosure includes a plurality of fluid convection apertures.

Abstract: An apparatus for connecting a power supply to an electrode within a high pressure, high temperature vessel is disclosed. The apparatus includes a conductor extending through the vessel such that the net force exerted upon the conductor by the vessel pressure is negligible. An elastomeric material seals the vessel conductor interface and the apparatus cools the sealing material to avoid softening thereof.

Abstract: A splice case housing electrical splices between two cables where the splices are immersed in an oil sealant having a specific gravity greater than water. The case includes holes located above the splices for receiving the electrical cables. Since the oil is heavier than water, if water were to enter the splice case, it would be above the oil and splices, thereby causing a hydraulic force on the oil, causing an even more intimate seal of the oil around the splices.

Abstract: An electrical feedthrough system for pressurized containers comprising a `T` shaped flexible member adapted to pass through an opening in a container and an epoxy used as a secondary seal and support. A conductor passes through the `T` shaped member which maintains a seal around the conductor. Electrical connections are made to terminals at either end of the conductor.

Abstract: An arrangement for mounting lead-through conductors is disclosed. A ceramic plate is sealed between two steel flanges. The conductors pass through the ceramic plate and are sealed on both sides. When one side of the plate is exposed to high pressure, low temperature gas, and the other side of the plate is exposed to high vacuum at a higher temperature, the plate is protected from excessive stresses by providing gaskets on one side of the ceramic plate having a different coefficient of thermal expansion than the gaskets on the other side of the ceramic plate.

Abstract: The present invention relates to the field of electrical engineering. A device for passing electrical and power installation conductors through a protective shell separating a clean zone from a contaminated one comprises a hollow metal casing in the form of a tube with end flanges embedded in the body of the protective shell, the latter having a metal shield attached to the contaminated zone side of the shell. The metal casing contains a main insulating through element having at least one hole through which the conductor is passed, the ends of the conductor being in the clean and contaminated zones. Each end of the conductor is fitted with additional insulating through elements fixed to seal fittings rigidly coupling the additional insulating through elements with the end flanges and the conductor ends. The conductor has at least one section in the form of a rod on the contaminated zone side and a thermocompensating multi-strand section coupled electrically to the rod.

Abstract: A high voltage cable, which is insulated with a solid insulated material, preferably cross-linked polyethylene, is connected to a pressure-gas-insulated conductor by means of a cable termination apparatus comprising a metal enclosure filled with pressure gas. The cable end is provided with a contact socket and secured in the metal enclosure by means of a pull rod fixed to the contact socket and oriented substantially in the axial extension of the cable end. A sealing device encloses a portion of the contact socket and the adjacent portion of the high voltage cable insulation.

Abstract: A transformer, with a core and windings, is arranged in a liquid-filled transformer tank and provided with an on-load tap changer suspended from the outside of the side wall of the tank. The terminal board between the tap changer and the tapping points of the transformer is arranged to incline at an angle of, for example, 30.degree. from the vertical plane.

Abstract: High voltage bushings for use within SF.sub.6 circuit breakers are provided with a tandem arrangement of an outer acid resistant gasket and an inner gas impervious gasket to prevent contact between the bushing oil and the SF.sub.6 gas.

Abstract: A single phase, metal encapsulated generator takeoff for generators of large power rating, which permits equalization of position tolerances in the vertical and horizontal direction when making the connection to a block transformer without effort in which each phase of the generator leadoff consists of a rigid inner conductor and a cylindrical, gas-tight tubular envelope which surrounds the inner conductor concentrically and in which the inner conductor is supported by support insulators, and which has ring-like expansion compensators at suitable spacings for taking up length changes caused by temperature variations. The inner conductor is connected to the terminals of the block transformer by expansion strips. The end section of the tubular enclosure of each phase facing the block transformer has two spaced joints, tiltable in all directions, in the form of expansion compensators.

Abstract: An ignition coil wherein the high tension terminal carried in a bore in the cap of the coil is movable relative to the cap. The terminal acts as a valve member in the bore and is movable between a position wherein the bore is closed and a position wherein the bore is open. The bore can be used as the means whereby oil is introduced into the casing of the coil if the coil is to be oil filled.

Abstract: A fluid-filled electrical bushing for connecting an electrical conductor in a fluid-filled transformer to an electrical conductor in another enclosure. The electrical bushing includes a safety device consisting of two coaxial flexible capsules which are joined to a plate disposed therebetween and which respectively communicate with the dielectric fluid in the bushing and with the dielectric fluid in the transformer. The plate, which is movable in opposite axial directions in response to the pressure difference between the dielectric fluid in the bushing and the dielectric fluid in the transformer acting thereon, alternately engages first or second electrical contacts to complete an electrical circuit indicating an over-pressure condition caused by internal arcing, or the abnormal expansion or an insufficient amount of dielectric fluid within the bushing.

Abstract: A device for passing an electric current through a wall subjected to excess pressure on its inner side, and comprising: a sleeve received in an aperture in the wall, which sleeve is integrally formed at its inner end with a collar engaging the inner surface of the wall; an electrical conductor for passing said electric current, which conductor includes a shaft passing through the sleeve, a head on the inner end of said shaft, and an inclined, e.g.

Abstract: An electrical penetration assembly is disclosed for providing a vapor and pressure seal between a conductor passing through two freestanding walls of a nuclear reactor containment which are subject to relative movement due to a seismic event. Penetration nozzles or tubes are placed through the walls of the containment when it is constructed. The penetration assembly is inserted into the nozzles and comprises a first subassembly fixed and sealed to a first penetration nozzle in the first wall and a second penetration subassembly in sliding or rolling engagement and sealed to a second penetration nozzle in the second wall. The sliding or rolling seal in the second nozzle allows the unrestrained reaction of the conductor to relative movement between the two freestanding walls during a seismic event without damage to the conductor or the penetration assembly. The penetration assembly also prevents the possibility of damage to either the conductor or the penetration assembly due to thermally induced stresses.

Abstract: Gas-insulated electrical apparatus is connected to oil-insulated electrical apparatus within an intermediate oil-filled tank having an oil pressure lower than the pressure within the oil-insulated apparatus. If gas leaks into the relatively low pressure oil, the gas contaminated oil cannot leak into the oil-insulated equipment. The intermediate oil-filled tank has larger electrical clearances than the oil-insulated apparatus.

Abstract: This electrical connection relates to an electrical link between a device in a metallic sheath insulated by a gas under pressure and a transformer insulated by a dielectric liquid. The connection comprises a jacket separating the interior volume of the transformer from that of the device and having a frustoconical insulating wall shielding the capacitor bushing and penetrating into the sheath. The insulating wall comprises on the outside of its base a flange having two concentric annular surfaces, one coming into contact with the sheath of the device and defining a junction plane between the interior volume of the device under gas pressure and the atmosphere, the other defining with another part a junction plane between the interior volume of the jacket filled with dielectric liquid and the atmosphere.

Abstract: A tapered electrical pass-through connector for allowing conductors to go through a hole in a vessel wall from the high pressure side to the low pressure side and capable of withstanding up to 150,000 PSI from the high pressure side. The small diameter end of the tapered connector is inserted into the vessel hole and the conductors extend through holes in the connector. A bonding agent surrounds the conductors in the connector holes and the holes are tapered and dimensioned to a small diameter to prevent the bonding agent from being blown out of the holes under pressure.

Abstract: A self-locking terminal assembly mountable on a base or plate. The terminal assembly includes an integral, one-piece terminal stud, an interior insulating member and an exterior insulating member. In an assembled state, the terminal stud, internal insulating member, external insulating member and mounting base interlock to substantially avoid rotation of the terminal assembly with respect to the base, under an applied torque.

Abstract: A travelling switching block for a metallic encapsulated high-voltage switching installation wherein at or in a switching block housing there are assembled together into a metallic encapsulated insulated and transportable structural unit at least one input duct or throughpassage and one output duct or throughpassage as well as power- and/or disconnector switches and possibly additional quick grounders, voltage converters, current converters and work grounders. At least each duct or throughpassage which extends upwardly in operating position is pivotable by means of an insulating medium tight pivoting mechanism into a transport position producing a smaller transverse profile.

Abstract: A separable connector module for connecting shielded electrical power cable and of the type including an insulating housing containing a bore contact assembly. The bore assembly includes a set of resilient receiving contact fingers attached to a rigid snuffer tube having on its inside wall a liner of ablative material. The improvement comprises that the portion of the snuffer liner adjacent the contacts is counterbored to have a greater inside diameter than the remaining portion of the snuffer liner. Such counterboring improves the performance of the connector for capacitive switching at relatively high voltages and in addition reduces the tendency for clear and restrike failures on typical distribution circuits.

Abstract: A face seal for an electrical feedthrough in a bulkhead subject to large ferential pressures comprising a metallic bolt routed through a hole in the bulkhead; an electrical conductor soldered to the head of the bolt on the high pressure side of the bulkhead; an epoxy-resin seal molded around and bonded to the protruding head of the bolt and having a conical undersurface mating with the bulkhead so that a thin ring forms the interface between the epoxy seal and the bulkhead; and, a nut screwed on to the threaded end of the bolt on the low pressure side of the bulkhead. The thin ring interface between the epoxy seal and the bulkhead deforms when the epoxy seal is subjected to external pressure so that the seal pressure is amplified.

Abstract: The transformer, in particular a potential transformer, comprises a generally planar bushing insulator, dimensioned for a liquid or gaseous insulating medium and coaxially enclosing a high-voltage connector, and a flange section enclosing the bushing insulator. The bushing insulator is also enclosed by an intermediate flange filled with a liquid or gaseous insulating medium. One end of the intermediate flange is connected to the instrument transformer and the other end of the intermediate flange is connected to a self-contained high-voltage bushing. A high-voltage connector of the transformer is connected to a conductor of the high-voltage bushing in the space enclosed by the intermediate flange.