Abstract: A method for preventing an electrical grid from failure in case of a temporary overvoltage includes providing an electrical grid line, a surge arrester and a disconnector device with a disconnector unit. The method further includes connecting the surge arrester at one terminal to the electrical grid line, connecting the surge arrester at its other terminal to a first terminal of the disconnector device, and connecting a second terminal of the disconnector device to ground potential. The method further includes interrupting the electrical connection in between the electrical grid line and the ground potential in response to a temporary overvoltage. The method further includes protecting the surge arrester from failure due to a thermal overload caused by the temporary overvoltage by operating the disconnector device before the surge arrester fails due to a thermal overload of the surge arrester.

Abstract: An installation structure of a temperature fuse is disclosed. The temperature fuse includes a first leg fixed to one surface of a printed circuit board (PCB), a bent part formed to be bent several times in an outer direction of the PCB from an end part of the first leg, and a second leg incorporated with the bent part and fixed to one surface of the PCB while being spaced apart from the first leg by a predetermined distance. The installation structure of the temperature fuse includes a third leg formed to extend from any one of the first leg and the second leg, a conductive member electrically connected to the third leg while being electrically isolated from the PCB, and a sensing part electrically connected to the third leg through the conductive member, and configured to detect whether a connection state between the third leg and the conductive member is normal.

Abstract: The invention relates to an overvoltage protection arrangement having: a plurality of planar varistors 2, 21, 22, which are arranged on a first side of a supporting plate 7; at least one gas arrester 10; and at least one thermal disconnection device, which is in close thermal contact with at least one of the varistors. The aforementioned components are surrounded by an outer housing 1, and electrical connection means 6, 61 for soldering to a printed circuit board are also provided on the second side of the supporting plate. The varistors 2, 21, 22 have a parallel stack arrangement, which is delimited on each of two opposing sides by an insulating partition wall 3, 31 which can be attached to the supporting plate.

Abstract: A basic unit portion configured by a standard unit and a variable unit portion whose shape is configured to be changeable. The basic unit portion includes: a first pressure tank with a first opening portion; a circuit breaker; a first bushing; a first disconnecting switch. The variable unit portion includes: a busbar; a second pressure tank with a second opening portion; a second bushing whose necessary number is disposed in accordance with the number of circuits to be externally connected; and second disconnecting switches which are arranged between the busbar and the second bushing. The first opening portion of the basic unit portion and the second opening portion of the variable unit portion are joined facing each other to form into a constitutional body.

Abstract: A surge arrester is disclosed. In an embodiment the surge arrester includes a first electrode for applying a first voltage potential to the surge arrester, a second electrode for applying a second voltage potential to the surge arrester, and a short-circuiting link for short-circuiting the first and second electrodes. The surge arrester further includes a retaining element for retaining the short-circuiting link, wherein the retaining element is embodied in such a way that it keeps the short-circuiting link at a distance from the first and second electrodes when a temperature is below a threshold value, and it shifts the short-circuiting link such that the short-circuiting link is pressed against the first and second electrodes and a short-circuit is produced between the first and second electrodes when the temperature exceeds the threshold value.

Abstract: A surge protection device having a housing, two connections for connection to a current path to be protected, and at least a first discharge conductor in the housing. In a normal state of the device, the first connection is electrically conductively connected to the first connection region of the discharge conductor, and the second connection is connected to the second connection region by at least one component. A metal safety element, which has two contact regions and a connecting region which connects the contact regions to one another, is arranged within the housing. The first contact region is electrically conductively connected to the second connection region and the second contact region is electrically conductively connected to the component in the normal state. The connecting region is a fuse by which brief pulse currents can be transmitted by the connecting region, whereas mains-frequency short-circuit currents overload the connecting region destroying it.

Abstract: A flashing beacon may include a signal unit, a control unit associated with the signal unit, a solar panel or collector, and an activation device that may all be mounted or otherwise positioned on a post of a roadway sign. Light units associated with the signal unit may be programmed to flash on and off in a unique wig-wag pattern. Further, a light bar may also be used with the beacon to generate an intense flash of light soon after activation of the beacon as an additional means of grabbing the attention of the operator of a vehicle.

Abstract: The 3-electrode surge protective device includes: a surge protective device body including: an earth electrode; a ceramic cylinder; and a pair of line electrodes; and a fail-safe spring including: an elastic mount portion; and a short-circuit portion, a conductive material that is sandwiched between the fail-safe spring and the body; and a pair of first lead pins provided on the pair of line electrodes; a second lead pin provided on the earth electrode. In a normal state, the conductive material support the short-circuit portion at a separation position where the short-circuit portion is separated from the outer peripheral face of the body and the first lead pins. In case where the body is overheated and the conductive material is melted, the short-circuit portion is moved to a contact position where the short-circuit portion comes into contact with the second lead pin and the first lead pins.

Abstract: An electrode is provided that is adapted to both pierce a barrier and providing an over-air discharge of electrical energy. In this regard, an over air discharge of electrical energy may be provided to an opposing side of a barrier. In one arrangement, the electrode includes a tapered point, which may be a hardened material, to facilitate piercing a barrier. In a further arrangement, the electrode incorporates an insulative shaft. In this arrangement, the insulative shaft electrically isolates a conductor of the electrode from a conductive barrier. Accordingly, the electrode may be utilized to pierce metallic enclosures and provide an electrical discharge for the purpose of altering the operation of electronic device within such enclosures.

Abstract: A structure for installing a lightning arrester between the cross arm mounted to the upper end of an electric pole and a power line is disclosed. A dead end clamp, the lightning arrester and an insulation reinforcing insulator are connected in series, an end of the insulation reinforcing insulator is connected to the cross arm by a shackle, a disconnector is connected to the voltage outlet portion of the lightning arrester, a grounding wire for diverting abnormal voltage to the ground is connected to the disconnector, and an insulation cover surrounds the dead end clamp and the voltage inlet portion of the lightning arrester.

Abstract: A disconnector assembly is provided for an arrester. A non-conductive housing has first and second opposite ends separated by an internal chamber. A first electrical terminal is connected at the first end. A second electrical terminal is connected at the second end. A capacitor engages and extends between the first and second terminals in the internal chamber. A sparkgap is electrically parallel the capacitor between the first and second terminals. A cartridge with an explosive charge is positioned in the internal chamber, and the cartridge is electrically parallel the capacitor and electrically in series with the sparkgap.

Abstract: A disconnector assembly is provided for an arrester. A non-conductive housing has first and second opposite ends separated by an internal chamber. A first electrical terminal is connected at the first end. A second electrical terminal is connected at the second end. A capacitor engages and extends between the first and second terminals in the internal chamber. A sparkgap is electrically parallel the capacitor between the first and second terminals. A cartridge with an explosive charge is positioned in the internal chamber, and the cartridge is electrically parallel the capacitor and electrically in series with the sparkgap.

Abstract: A disconnector assembly is provided for an arrester. A non-conductive housing has first and second opposite ends separated by an internal chamber. A first electrical terminal is connected at the first end. A second electrical terminal is connected at the second end. A capacitor assembly engages and extends between the first and second terminals in the internal chamber. The capacitor assembly includes a capacitor and a resistor electrically connected in series. A sparkgap is electrically parallel the capacitor assembly between the first and second terminals. A cartridge with an explosive charge is positioned in the internal chamber, and the cartridge is electrically parallel to the capacitor assembly and electrically in series with the spark gap.

Abstract: A disconnector assembly is provided for an arrester. A non-conductive housing has first and second opposite ends separated by an internal chamber. A first electrical terminal is connected at the first end. A second electrical terminal is connected at the second end. A capacitor assembly engages and extends between the first and second terminals in the internal chamber. The capacitor assembly includes a capacitor and a resistor electrically connected in series. A sparkgap is electrically parallel the capacitor assembly between the first and second terminals. A cartridge with an explosive charge is positioned in the internal chamber, and the cartridge is electrically parallel to the capacitor assembly and electrically in series with the spark gap.

Abstract: A disconnector assembly is provided for an arrester. A non-conductive housing has first and second opposite ends separated by an internal chamber. A first electrical terminal is connected at the first end. A second electrical terminal is connected at the second end. A capacitor engages and extends between the first and second terminals in the internal chamber. A sparkgap is electrically parallel the capacitor between the first and second terminals. A cartridge with an explosive charge is positioned in the internal chamber, and the cartridge is electrically parallel the capacitor and electrically in series with the sparkgap.

Abstract: In order to provide a good gas-insulated circuit breaker which is compact and easy in assembling and preparation, a gas-insulated circuit breaker 100 is constructed with a grounded enclosure 104 enclosed a insulation nature gas, a current interruption part having a fixed contactor 115 arranged in the grounded enclosure 104 and a movable contactor 116 to be contacted with and to be separated from the fixed contactor 115, and an operating mechanism 101 to output a driving force to drive the movable contactor 116, wherein a grounded enclosure side main rotating shaft 110 connected to the movable contactor 116 through a connection member and a main output shaft 102 for outputting a rotating force to actuate the movable contactor 116 through the grounded enclosure side main rotating shaft 110 provided on the operating mechanism 101, are arranged on a coax so as to be coupled with a gear coupling 120, and the operating mechanism 101 is arranged almost under the grounded enclosure 104.

Abstract: Over voltage protection is provided for electronic circuits by disposing one or more ground bars for diverting harmful currents away from the sensitive electronic circuit elements. The ground bars are each associated with a row of contact portions of the electronic circuit. Microgaps between each contact portion and the corresponding ground bar are designed to provide an electrical conduit from the contact portion to the ground bar when normal operating voltages are exceeded, thereby channeling excess current harmlessly to ground. Under normal operating conditions, however, the microgaps act as electrical barriers, insulating the contact portions from ground. The microgaps may be filled with any combination of air, vacuum, or known variable voltage material.

Abstract: There is provided a surge absorber without chips in which a pair of discharge electrodes arranged facing to each other in a housing 1 are fixed by welding of the housing 1 with a distance between the discharge electrodes maintained. Clean and dry air or a mixed gas mainly comprising such air is sealed in an air chamber 4.

Abstract: A discharge gap device which is provided between an antenna input terminal or a secondary side earth and a commercial power source, or between the power lines of a commercial power source as a ground discharge countermeasure for electrical equipments such as a television set, a video cassette recorder, and a television and video compound device. The discharge gap device functions only as a discharge gap unit and has two conductors. Normally, the conductors are not electrically connected to each other, and upon application of over-voltage, discharge occurs between the conductors; that is, the conductors are electrically connected to each other.

Abstract: There is provided a surge absorber without chips in which a pair of discharge electrodes arranged facing to each other in a housing 1 are fixed by welding of the housing 1 with a distance between the discharge electrodes maintained. Clean and dry air or a mixed gas mainly comprising such air is sealed in an air chamber 4.

Abstract: A lighting arrester in the form of a double-ended polymer enclosure contains one or more varistor discs in vertical alignment having terminals at the opposing ends for external electrical connection. The discs are formed from a zinc oxide composition with metal electrodes on opposing faces that are electrically connected with each other and with the end terminals by U-shaped metal straps.

Abstract: A device for connecting, and then isolating and disconnecting an arrester includes a non-conductive housing with two electrical terminals. The housing has opposite ends separated by an internal chamber. The terminals are mounted at the housing ends. A resistor engages and extends between the terminals in the housing internal chamber. A cartridge with an explosive charge is mounted in the internal chamber adjacent the resistor. A gap spacer surrounds the cartridge, is adjacent one of the terminals and is spaced from the other terminal.

Abstract: A gas insulated switchgear apparatus comprising connection conductors connected to a connection portion to breaker side, disconnectors connected to the connection conductors, cable heads connected to the disconnectors, lightning arresters having one end connected between the disconnectors and the cable heads, single phase voltage transformers provided in one of three phases and having one end connected between the disconnectors and the cable heads and a disconnector cylindrical vessel filled with an insulating gas and containing the connection conductors, the disconnectors, the cable heads, the lightning arresters and the single phase voltage transformers therein. The cable heads are disposed so that the axis of the disconnector cylindrical vessel and the axes of the cable heads are parallel. The lightning arresters are disposed so that the axis of the disconnector cylindrical vessel and the axes of the lightning arresters are parallel.

Abstract: A surge protection device comprising surge protector having a first terminal and a second terminal, one of the terminals being conductively connected to a first power transfer mechanism, such as a source of electrical power, and another of the terminals being conductively connected to a second power transfer mechanism, such as a sink of electrical power. The surge protector is operable to conduct current form one of the power transfer mechanism to another of the power transfer mechanism in the presence of a prolonged overvoltage surge across the first and second terminals of the surge protector. The surge protection device includes a mechanism for automatically disconnecting one of the terminals from one of the power transfer mechanisms in the presence of a prolonged overvoltage surge across the first and second terminals.

Abstract: A discharge-type surge absorbing element that absorbs a surge by using the discharge that occurs between a discharge interval arranged within a sealed container filled with a discharge gas. The discharge-type absorbing element is characterized by a plurality of discharge electrodes connected to lead wires and disposed within a sealed container filled with a discharge gas. The discharge electrodes are disposed within the container so that they face each other and so that a discharge gap is formed between the discharge electrodes. The lead wire from each of the discharge electrodes passes through the sealed container and extends externally. A layer is disposed on the inside surface of the sealed container, at least between the lead wires. The layer has good creeping discharge properties and is made from the material in the discharge electrodes. A very small gap is formed between the lead wires and the end of the layer.

Abstract: An overvoltage protection element for discharging transient overvoltages, with two electrodes (2), a disruptive discharge-spark air between the electrodes (2) and a housing (4) containing the electrodes (2). Each electrode (2) has a connecting leg (5) and an arcing horn (6) which runs at an acute angle relative to the connecting leg (5). The disruptive discharge-spark air gap is formed by facing surfaces of the arcing horns (6) of the electrodes (2), which are spaced from one another. In preferred embodiments, the arcing horns (6) of the electrodes (2), in their areas near the connecting leg (5), are provided with at least one hole (7) running therethrough which, preferably, has a diameter that is less than 2 mm.

Abstract: A gas-filled discharge tube includes a cylindrical casing (11, 31), a terminal member (12, 13; 32, 33) for closing an open end of the casing, an inert gas sealed within the casing, a gas sealing tube (16, 38) connected to an outside of the terminal member, and gas introduction paths (17, 40) formed in the terminal member so as to communicate between an inner space of the gas sealing tube and an inner space of the casing.

Abstract: A miniature overvoltage protection device including a back-up air gap for use in miniature telephone modules and related equipment includes a generally U-shaped bracket adapted to receive an overvoltage protection device thereon and has a bracket insulating member with a dielectric disposed between the overvoltage protection device terminals and the ground provided on a U-shaped bracket in order to provide back-up air gap protection. In addition, it may include a thermally sensitive material to insulate the overvoltage protection device from the grounding bracket which is activated upon excessive heat occurring in the overvoltage protection device.

Abstract: A flange, which is integrally formed with the inner surface of the cylindrical member, is located at an intermediate point between the end surface position of the cylindrical member to which the electrode plate of one of the discharge electrodes is sealed and the tip position of the discharge electrode portion of that electrode. Both end surfaces of the cylindrical member are hermetically attached with the discharge electrodes. This arrangement prevents inner flashovers without affecting the discharge characteristics of the discharge tube and also ensures manufacture of discharge tubes with no possibility of gas leakage with very high yields even if the machining precision is not so high.

Abstract: As a known "back-up device" for a gas-filled over-voltage arrester, a voltage-dependent resistor (6) is arranged centrally in a housing with the over-voltage arrester (1). The varistor (6) can, in this connection, be sealed with a moisture-repelling substance and it is arranged concentrically to a connecting pin (5) of the over-voltage arrester. By means of an auxiliary electrode (8) of annular disk shape placed on the varistor (6), an air gap (13) from the connecting pin (5) can be formed. The varistor, after its response, can be short-circuited via this air gap.

Abstract: The discharge tube of this invention does not employ special shapes of electrodes that are difficult to manufacture, but can still provide a uniform electric field. The electrodes are disposed in the inwardly drawn portions of the cylindrical body in such a way that the opposing front end surfaces of the electrodes are recessed from the inner surfaces of the inwardly drawn portions in a direction that they move away from each other. The discharge electrodes therefore do not project into the inner space of the cylindrical body but are enclosed by the inwardly drawn portions so that they are protected against influences of external electric fields from outside the discharge tube, thus assuring stable and reliable discharges.

Abstract: A MELF (Metal Electrode Face Bonding Device) surge absorbing element which can be connected across a pair of input lines of an electronic device. The surge absorbing element is secured in electrical contact with the input lines by a conductive heat releasable adhering means, e.g., a solder. A spring is positioned in biased relationship against the surge absorbing element. When the surge absorbing element is subjected to overvoltages or overcurrents continuously across the input lines, the surge absorbing element heats up, which, in turn, heats the adhering means. When the temperature reaches a predetermined value, the adhering means releases its securement of the surge absorbing element, e.g., the solder melts, and no longer holds the element. When this occurs, the bias of the spring means positioned against the now unsecured surge absorbing element serves to move the element away from and out of electrical contact with the adhering means and, in turn, the input lines.

Abstract: A surge absorber in which a thermal response switch is inserted in an input line at the input side of a surge absorbing element. The switch includes a conductive spring piece and a conductive hook piece. The base end of the conductive spring piece is fixed on either the first lead or the second leads and the tip of the conductive spring piece is provided with a pawl. The base end of the conductive hook piece is fixed on either the first lead or the second leads and the tip of the conductive hook piece is engaged with the pawl. At least one of the conductive spring piece and the conductive hook piece is made of a thermal response piece. Upon stopping of the applied continuous overvoltages or overcurrents, the switch can automatically be restored depending on an extent of the overcurrent by a manual operation.

Abstract: A thermal overload protection device for electronic components, in particular for the telecommunication and data technology. The overload device has a spring-elastic shorting link 6 and a melt element 13. Tripping of the shorting link 6 performed in dependence of the fusing process of the melt element 13. In order to obtain a SERVO FAIL SAFE behavior, the spring force of the shorting link 6 is arbitrarily high. Devices 15, 17, separate from each other, are provided, according to the invention, for separately tripping and actuating the shorting link 6.

Abstract: A surge voltage protector having a tubular ceramic part as an insulator, and having metal electrodes soldered onto the end faces thereof. Each electrode is electrically connected in each case to an ignition aid applied at least to the inside wall of the ceramic part. The inside edges of the surfaces joining the ceramic part to the electrodes are each provided with a chamfer whose chamfer angle is 15.degree. to 60.degree. relative to the plane of the joining surfaces. The width projected onto the plane of the joining surface is 0.05 to 0.4 mm.

Abstract: A surge absorbing element is parallel connected to an electronic device via a pair of communication lines. A normally closed thermal response switch is serially connected between the electronic device and the signal source on the input side of the surge absorbing element. When a surge voltage is instantaneously applied to the communication lines, the thermal response switch remains in the closed position and the surge absorbing element acts to suppress the surge voltage. When an overvoltage or over current is continuously applied to the communication lines, the thermal response pieces of the thermal response switch open and simultaneously release the movable body. Consequently, the electronic device is disconnected from the signal source, thus stopping the continuous overvoltage or overcurrent from flowing to the electronic device and the surge absorbing element. Simultaneously, the reset pin is projected through the casing.

Abstract: A lightning surge protector, comprises a current limiting element in a pressure-proof housing. The pressure-proof housing is composed of a conductive material and coupled with an upper electrode member. Also, a self arc-extinguishing LSP comprises a current limiting element and upper and lower electrode members housed and fixed in a conductive pressure-proof housing opened at its lower portion through a suspension structure composed of a suspension rod. The outside and inside of the housing are covered and filled with an insulator, so that, upon occurrence of an internal arc due to a short-circuit fault or the like, the energy due to the arc causes the lower electrode member to break the insulator in the vicinity of an opening portion of the conductive pressure-proof housing so as to electrically connect the conductive pressure-proof housing to a part of the lower electrode member.

Abstract: An excellent lightning arrestor insulator is provided having a discharge gap portion and an arrestor ZnO element device both built in a body of the insulator, comprising projected discharge electrodes arranged in the inside of the insulator body, the discharge gap portion being formed of a heat resistant protrusion arranged in the inside of the insulator body and surrounding the discharge electrodes, and a pair of metal plates and/or electrically conductive ceramic plates sandwiching the protrusion from both sides thereof and electrically connected to the discharge electrodes, the pair of plates being joined and airtightly sealed to the protrusion via an inorganic glass. The arrestor ZnO element device has a highly reliable airtight fixing and sealing structure so that accidents in a power supply or distribution line at a normal working voltage can be substantially eliminated, and damages caused by hygromeration and lightnings can be noticeably decreased.

Abstract: A surge arrester comprises a plurality of cylindrical arrester elements (11) of metal oxide varistor material which are arranged, with confronting end surfaces, between two end electrodes (13) in an elongated protective housing (10) which is resistant to deformation under the operating conditions for the surge arrester. The housing is of cross-linked HD polyethylene and is shrunk onto the envelope surfaces of the arrester elements and onto envelope surfaces on heat-absorbing metallic bodies (12) arranged between the arrester elements.

Abstract: A triggered surge suppression network is disclosed comprising a low voltage clamping device, a crowbar device and a trigger device. The voltage clamping device and the trigger device are connected in parallel; and these devices are connected in series to the crowbar device. The resulting circuit is connected across a voltage supply, in parallel to a load. The trigger device causes the crowbar device to break down at a pre-set value and discharge the energy of the surge through the low voltage clamping device. The breakdown voltage of the network will depend essentially on the breakdown voltage of the crowbar device while the peak voltage supplied to the load during the surge will independently be determined by the clamping voltage of the voltage clamping device.

Abstract: An inexpensive, compact, portable, visual indicator electrical plug-type surge protector which comprises an electrical plug body composed of a molded transparent polymer, the plug body having an extended male grounding prong and a pair of male electrical prongs on one face and a female receiving grounding inlet and a pair of female receiving inlets on the opposite face. The plug body contains in a visually indicating position, generally slightly below the surface of the plug body, a metal oxide varistor electrically connected to the electrical outlet plug so as to prevent electrical surges from passing through the surge protector from the electrical source into which the electrical plug-type surge protector is plugged and to be activated and to change color on the occurrence of an electrical surge so that the user of the surge protector will know when the electrical surge has been received and thereby be able to replace the surge protector with a new surge protector.

Abstract: In the past, a power fuse need be replaced after the current limiting operation and cannot be repeatedly used. To solve this problem, there has been proposed a permanent fuse or the like which uses an alkaline metal having a low melting point such as Hg, K, Na, etc.These are harmful to human body, and since they are completely vaporized, an insulated layer of a vessel cannot be removed, thus giving rise to a difficulty toward higher voltage.The present invention makes best use of characteristic of carbon which sublimates. A plurality of boundary layers of carbon lumps are disposed in series or in series and parallel, and electrode potential drops at the time of large current and potential drops of arc column under high atmosphere presssure which produces for a short period of time are utilized to effect current limiting.

Abstract: A line protector for a communications circuit. The line protector has an overvoltage arrestor such as a three electrode gas tube, two of whose electrodes are connected to the line input terminals of the protector by associated conductive elements projecting from the protector base. The third electrode is connected to the ground terminal. The line protector also has two positive temperature coefficient resistors (PTCRs) which protect against marginal overcurrents. Conductive elements connected to the line protector's equipment terminals also project from the base in the same direction as the line input terminal conductive elements project. Each PTCR is in contact with an associated one of the two line input terminal conductive elements and an associated one of the two equipment terminal conductive elements.

Abstract: A protector module (30) for protecting the conductors of a telephone loop cludes a pair of protector assemblies (40-40') which are supported within a common housing (32). A gas tube voltage protection subassembly (42) of each protector assembly is connected electrically to a grounding subassembly (44) for causing current associated with excessive voltage surges to be conducted to ground. A first electrode includes a portion which extends through annular dielectric and metallic members and an opening of an open-ended metallic container (93) to engage a shunting element (62) of a current protection subassembly (41). The superimposed annular members are held in engagement with the first electrode at a substantially constant pressure by axial forces applied by turned-in portions (109--109) of a side wall of the metallic container. The shunting element is supported at one end of the line pin in an initial position by a fusible material.

Abstract: An arrester support and disconnector structure enclosed, in one embodiment, a cylindrical housing having a lower wall with a weakened zone. Electrically conductive members extend through the upper and lower walls of the housing and make electrical connection with the arrester and a ground wire, respectively. Between the conductive members is an explosive charge which is detonated by the passage of excess current, thereby removing the lower member. The cylindrical body has an exterior recess to receive a supporting strap. In another embodiment, the support structure includes an elongated nonconductive body mounted at one end to a conventional support bracket. At the other end an upper surface supports an arrester and a housing below that surface contains the disconnector, again containing upper and lower conductive members with an explosive charge therebetween. The housing surrounding the conductive members has a weakened zone which is separated when the charge is detonated by excessive current.

Abstract: A metal oxide varistor (MOV) is directly electrically connected between a line conductor and ground to dissipate the energy associated with voltage surges appearing on the line conductor. A thermostatic switch, in the form of a resilient arm held in electrical connection with one of the MOV electrodes by low melting point solder, opens in response to a failing MOV to insert a spark gap electrically in series with the MOV. Overvoltage protection is thus maintained, albeit limited to higher level voltage surges.

Abstract: A protection module for connecting blocks is intended notably for at least one line wire of a telephone system and comprises a case having a ground terminal, an input terminal and an output terminal for each line wire, and a first lightning arrester having a first terminal connected to the ground terminal and a second terminal clamped resiliently between two extensions of the line terminals, respectively. Another lightening arrester has a first terminal connected to the ground terminal and a second terminal clamped resiliently between two extensions of the other pair of line wire terminals. An orifice registering with a third pair of terminals parallel to the other pair of line wire terminals is adapted to guide a detachable element which comprises an insulating portion adapted to be fitted between the terminals of the third pair of the lightning arresters and each extension of the pair of output terminals.

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 conventional automatic electric circuit breaker is combined with a varistor to provide both overcurrent and overvoltage circuit protection. The varistor is connected between the load end of the circuit breaker and neutral to shunt to ground the currents associated with lightning induced voltage surges. As a fail-safe feature, abnormal leakage current drawn by the varistor under normal line voltage conditions directly and/or indirectly heats the thermal element of the breaker trip unit, ultimately tripping the breaker.

Abstract: A device for protecting electrical appliances from electrical surges having male prong members to connect the device to an electrical wall outlet; a female receptacle to receive a plug of the appliance; a self-restoring, current diverting spark gap means for interrupting current at the female receptacle at a predetermined voltage level.