Abstract: An electrical insulating coating of thermosetting polymeric material for a surge arrester valve element of silicon carbide particles bound together within a ceramic matrix, in which the coating is applied in powder form. Curing of the coating is effected either by a heating cycle following the application of the powder insulating coating, or by preheating of the valve element before application of the powder coating. Alternately, the insulating coating can be applied as a plasma spray, making post-curing unnecessary.

Abstract: Power gaps for protection of electrical equipment against overvoltages and having high current handling capacity consisting of two carbon electrodes mounted in an arrangement in which the lower cylindrical electrode has an inner conductive sleeve reaching proximate to but spaced from the end of the electrode for providing a centrally located, relatively stable, low resistance path for the arc current.

Abstract: A station arrester employing metal oxide varistors has varistors whose capacitances increase in a direction measured from the ground side of the arrester. An approximately uniform voltage distribution can be produced across the varistors when appropriately graded according to their positions in the varistor stack. In this configuration, the varistor disks located near the top or line end of the stack are not subjected to increased thermal stresses.

Abstract: Lightning arresters comprising each non-linear resistor made of a main component of zinc oxide and the other minor component are connected between a steel tower and a power transmission cable supported on the steel tower by an insulator and between the power transmission cables in different phases whereby the lightning resistance of the aerial power transmission system is improved.

Abstract: A spark gap switching device for high peak currents including a pair of main electrodes with protruding, opposing sub-electrodes, surrounded by high permeability cores typically of ferrite material. Small air gaps separate the sub-electrodes. The switch is activated by an over voltage or the like causing one of the sub-electrodes to breakover producing a flux time rate of change in the core. A voltage is induced in the non conducting sub-electrodes causing aligned pairs to rapidly increase in potential difference until one by one they all conduct.

Abstract: A gas cooled lightning arrester includes a plurality of zinc oxide blocks which are joined together to form serially connected non-linear resistors and capacitors. The blocks may be joined by clamps or metal plates may be bonded to the ends of the blocks. Cooling fins integral with the zinc oxide blocks or provided by the metal plates facilitate heat dissipation. The housing for the lightning arrester includes an inner wall which defines a channel for the convection flow of gas coolant.

Abstract: A zinc-oxide surge arrester, in which a plurality of zinc-oxide elements each having a through hole at a central portion are stacked in such a manner that an insulating supporting rod having at least one fixed end is inserted in the through hole of each element, can increase the heat transfer area of the element and simplify the supporting structure.

Abstract: A lightning arrester device comprises a serial connection of a non-linear resistor and a linear resistor as a lightning arrester and a pair of electrodes disposed at both ends of the lightning arrester with a spark gap being defined between the electrodes thereby preventing a damage of the lightning arrester caused by direct lightning to a power transmission line.

Abstract: A surge voltage arrester utilizes for surge protection a varistor of the zinc oxide type between a line terminal and a ground terminal. The varistor is of a type that has a resistance which decreases as increasing voltage is applied thereacross. With increasing temperature the leakage current through the varistor increases at a given voltage. At a critical temperature and voltage condition, the varistor is subject to a thermal runaway condition which would cause the varistor to fail expelling hot particles. To avoid this failure condition, a fail-safe mechanism is provided which connects the line terminal to the ground terminal by-passing the varistor when there is an overcurrent condition on the line that results in heating of the varistor.

Abstract: A surge arrester of compact construction includes a housing formed preferably of elastomeric material through which a pair of spaced terminals protrude and between which a stack of metal oxide varistor discs is disposed and connected in series therewith. Disposed below the lower one of the discs and in contact therewith is a conductive base plate and an electrode is spaced somewhat from the lower surface of the base plate to form a gap and is provided with shunt means connecting the electrode with the upper surface of the lower disc so that an overvoltage surge condition and the resulting arc across the gap establishes a shunt circuit around the lower disc.

Abstract: A varistor element is press-fitted into a recess formed in one surface of a metal electrode and protrudes a preselected distance out from the electrode surface. A second metal electrode is positioned in line with but spaced from the varistor by a TEFLON washer of selected thickness to fix the length of the air gap between the varistor and second electrode. The length of the copositioned air gap between the metal electrodes is similarly fixed by the washer and the protruding portion of the varistor. The assembly is held by a central rivet with a spring cup washer positioned under its peened end to hold elements in contact while absorbing some of the discharge force. The rivet is insulated by a nylon tube integral with an open-end cover for the assembly held at the closed end by the rivet head. When a high voltage surge is applied across the arrester assembly, the varistor-to-metal gap ionizes quickly to initiate discharge.

Abstract: A varistor disc is press-fitted into recesses formed in opposite surfaces of two metal electrodes, its length selected so that a predetermined air gap remains between the electrode surfaces in parallel to the varistor path. The assembly is held by a rivet inserted through the three elements with a spring cup washer under the peened rivet end to absorb dynamic discharge forces. The rivet is insulated by a nylon tube integral with a dust and moisture cover, held at one end by the rivet head and open at its other end for release of gas and particles upon discharge. The varistor dissipates static voltage buildup and low voltage surges. High voltage causes arcing between varistor and electrodes within the air gap, which creates a surge discharge across the air gap between electrodes to dissipate surge energy and protect the varistor element.

Abstract: A line protector for a communications circuit comprises an insulating base having a ground pin and two pairs of line pins, one pair for each side of the line, projecting through the base. Each pair of line pins has a contact electrically connected thereto and projecting away from the base. The ground pin also has a contact projecting away from the base and spaced from the line pin contacts. A metal oxide varistor having opposed faces provides surge voltage protection for each side of the line. The line pin contacts are bonded to one face of the varistor while the ground pin contact is bonded to the other face of the varistor. Electrically conductive spring clips span the varistor and are pressed toward its opposite faces and in electrical contact with the ground pin contact. An insulating sheet is interposed between the clips and the line pin contacts to prevent one or more of the clips from grounding the line except in such surge condition that heats the varistor sufficiently to melt the insulation.

Abstract: A main arrester body is formed of a stack of superposed nonlinear resistors composed of sintered zinc oxide and longitudinally disposed within an enclosed housing filled with SF.sub.6. A plate-shaped conductor extends from the higher voltage end of the stack to run radially outward and downward, and a lead is connected to the conductor to be transversely extended and sealed through the housing until it is connected to a horizontally disposed bus.

Abstract: A gapless surge arrester is disclosed herein and includes a porcelain outer casing and a stack of zinc oxide discs located within the casing for passing surge currents therethrough. Silicon dioxide, preferably sand, is provided between this stack in the casing for transferring heat from the discs to the porcelain outer casing as a result of the surge current and for absorbing fault energy where necessary by changing states.

Abstract: A stack of nonlinear resistors of sintered zinc oxide superposing one another is connected across a bottom of a grounded cylindrical housing and a high voltage conductor insulatingly supported by the housing. Within the housing a shielding conductor slantingly hangs from the connection of the stack and conductor. Alternatively, the shielding electrode may extend from the high voltage conductor to run along the longitudinal axis of the housing. A plurality of nonlinear resistors are divided in several stacks and serially interconnected between the shielding conductor and the inside of the housing to be radially outward inclined to the shielding electrode. Such stacks may be disposed close to the free end portion of the shielding electrode.

Abstract: A heat transfer system for voltage surge arresters employs a dual radius arrester housing in combination with a plurality of sleeved zinc oxide varistors to efficiently cool the varistors during operation. The sleeved varistors are held in thermal contact with a large portion of the porcelain housing. The porcelain housing provides a heat sink facility to the arrester both during normal operating and voltage surge conditions.

Abstract: A pair of varistor disks, each having one face thereof coated substantially entirely with electrode material and another face thereof coated with spaced-apart electrode material, such as in two semicircular patches, are joined together so that said faces coated with a single electrode are coincident. This configuration reduces by a factor of two the over-all area required for equal current density as compared with certain prior varistor configurations. The varistor of the present invention also exhibits a lower diameter-to-thickness ratio and hence provides a significantly stronger mechanical structure. Additionally, the varistors of the present configuration may be readily provided with grooves between electrode surfaces so as to increase the interelectrode spacing, without significantly reducing the mechanical strength of the device. The invention of the present structure also permits flexible lead configurations.

Abstract: In a grounded metallic housing of circular cross section three electrodes are disposed at equal angular intervals in a circle concentric with the housing to extending parallel to the axis of the latter. Three stacks of non-linear resistors are connected at one end to a corresponding one of the electrodes and at the other end to the peripheral edge of the bottom of the housing to be tilted radially outward.

Abstract: A protective device for protecting from abnormal voltage such as a lightning arrester comprises an earthing cylindrical metallic casing; an electrode or conductive substrate which is disposed to the direction of the axis of the metallic casing; an insulating pipe which is in spread-out shape and is disposed between the metallic casing and the electrode or the conductive substrate; and a plurality of non-linear resistors which are disposed in said insulating pipe wherein said non-linear resistors are respectively connected so as to be substantially similar to the potential distribution in said metallic casing.

Abstract: Voltage surge arrester devices having predetermined shunt gap sparkover voltages are provided by the series combination of high- and low-exponent varistors. In one embodiment the high-exponent varistor comprises zinc oxide and the low-exponent varistor comprises silicon carbide.

Abstract: An electrical arrester structure includes an arc quenching chamber in which are located a pair of spaced principal electrodes between which a quenched arc gap is formed, an associated blow-out coil for magnetically influencing and expanding the arc formed between these electrodes and an auxiliary electrode which together with the principal electrode adjacent thereto forms an auxiliary arc gap. The auxiliary electrode is connected directly to one end of a leakage resistor and the other end of this leakage resistor is electrically connected either through the blow-out coil or directly to the principal electrode which is adjacent the auxiliary electrode with the result that the auxiliary arc gap will fire before the voltage protective level of the arrester is reached and cause the leakage resistor which is series connected with the quenched arc gap to be bridged.

Abstract: Arresters for protecting electrical equipment from damage or destruction due to overvoltage surges, for example overvoltage surges caused by lightning strokes, are provided that are fabricated or assembled integrally with cable taps, cable joints, separable insulated connector apparatus, and overhead arrester assemblies. Arresters are also provided for insertion in arrester receptacles which are integrally provided with cable taps, joints, separable insulated connector apparatus or cable receptacle devices. The arresters include a laminated enclosure for excluding the atmosphere, air and moisture, along the outer surfaces of arrester components and along the outer surface of an insulating housing layer, as well as along interfaces with insulated power cable and separable insulated arrester components. The housing is either fabricated by coating or molding onto the arrester components or by inserting the arrester components in an interference fit relationship into a premolded elastomeric enclosure.

Abstract: The arrester comprises an insulating housing with end terminals and a plurality of varistors inside the housing electrically connected between the terminals. The varistors are provided individually or in groups with a heat transfer and sinking collar which is electrically insulating and thermally conducting. The collar may be in thermally conducting contact with the inside wall of the housing to improve heat dissipation to the housing. The configuration of the collar is such that when it is installed in the housing, there is a passageway through it to provide a longitudinal space in the arrester for accommodating arcing and for the venting of gas in the event of an arrester failure.

Abstract: Electrical devices which include electrical elements positioned within a container are assembled at the manufacturing site and then transported to the erection site by forming the container with openings therein such that transport supports can be inserted therethrough to contact the electrical elements. The transport supports may then be secured in place between the elements and the container walls. Upon erection into functioning position, the transport supports are removed and the openings covered with lids so that, if desired, the container can then be filled with gas.

Abstract: Flat internal components of an arrester are stacked longitudinally inside the insulating housing cylinder with a perimeter portion contacting the inside wall of the housing. Each component has a guide channel extending longitudinally on its perimeter portion opposite the portion in contact with the wall. A resilient rolling bias member is disposed in the channel of each component in a deformed stressed state and forces the components laterally against the wall.

Abstract: Lightning protection is provided by an electronic valve molded mainly of silicon carbide powder. The manufacturing cost and high reject rate of previous ceramic bonding is greatly reduced by bonding with epoxy resin, the mixture being pressure molded. The surface-tracking characteristic of epoxy resin is rendered harmless by covering the periphery of the molded piece with insulation and by inclusion of alumina powder in the mix. The insulating sleeve is extended to provide a hood preventing harmful migration of an ionized arcing path.

Abstract: The invention relates to a lightning conductor having a gaseous enclosure. The lightning conductor which comprises an enclosure filled with insulating gas and is arranged inside a metallic casing under dielectric fluid pressure containing a high-tension electrical device is characterized in that the said enclosure is provided with means for making the insulating gas flow. The invention is applied to the protection of high-tension electrical devices.

Abstract: A surge voltage arrester contains a series circuit arrangement of spark gaps and voltage-dependent resistors. The voltage-dependent resistors include a semi-conductive material having an exponent .alpha. of voltage dependence which is at least 10. The surge voltage arrester makes it possible to manufacture high-capacity surge voltage arresters with spark gaps exhibiting a very simple construction. This effect is based on the fact that the voltage-dependent resistors assume the actual arrester function and the spark gap, therefore, are essentially only used for switching the arrester on and off. The arrester is particularly suitable for application in networks for electrical power distribution.

Abstract: A valve type surge arrester includes a line terminal disposed partially within and spaced from a conductive outer housing that functions as a ground terminal. The surge arrester is formed with an extremely compact configuration and occupies only approximately 0.17 cubic inches of volume. Also disposed within the housing is a spark gap in series with a power follow current limiting valve block. An insulating spacer is disposed within the conductive outer housing. The spacer includes two integrally formed shoulders that determine the spark gap spacing and an integrally formed, tubularly shaped, extending portion that electrically insulates portions of the valve block from the conductive outer housing. An elastic sealing gasket resiliently compresses the line terminal, the spark gap structure, and the valve block components into series contact against an inner end of the housing.