Abstract: A power fuse assembly includes a fuse mounting, a fuse unit, and a hinge assembly. The fuse unit is configured to carry current from a line connection to a load connection. The hinge assembly is configured to be removeably coupled to the fuse unit and to allow rotation of the fuse unit relative to the fuse mounting. The hinge assembly including: an inlet configured to accept incoming gases produced by the fuse unit in response to an overload event, the inlet having a first orientation; an outlet in fluid communication with the inlet, the outlet having a second orientation that is not equal to the first orientation; and a diverter component disposed between the inlet and the outlet, the diverter configured to guide the flow of the gases between the inlet and the outlet.

Abstract: A protection device comprises a substrate, a fusible element, a flux and an insulating cover. The fusible element is disposed on the substrate and connects to a power line of an apparatus to be protected. The flux is disposed on the fusible element. The insulating cover is secured on the substrate to form a room for receiving the fusible element. The insulating cover has a bottom surface facing the substrate, and a plurality of protrusions are formed and distributed on the bottom surface to hold the flux in place.

Abstract: A multiple operation cutout and a method of operating the same and providing multiple fuse operation provides an assembly for a plurality of fuses. A mechanism individually and sequentially engages the fuses responsive to operation of the fuses.

Abstract: Fused load interrupters have up to now used claw terminals or screw connections for connecting to horizontal busbars in a switchgear unit. Fused load interrupters have not been suitable until now for connecting to vertical busbars in switchgear units. At least one embodiment of the invention provides a fused load interrupter with plug contacts, such as are known from load interrupters with fuses, thereby allowing fused load interrupters to replace the more expensive load interrupters with fuses in switchgear units with vertical busbars.

Abstract: A wireless secondary assembly is disclosed for use in an electrical distribution network. The secondary assembly may include a wireless source electrically connected to a first electric cable and adapted to emit an electromagnetic power signal. A wireless receiver is electrically connected to a secondary device and adapted to receive the electromagnetic power signal and convert the electromagnetic power signal to electricity to power to secondary device.

Abstract: A protection element and a secondary battery device employing the protection element are provided for stably retaining a flux on a soluble conductor at a predetermined position, so as to enable appropriate blowout of the soluble conductor in the event of an abnormality. The protection element has a soluble conductor which is disposed on an insulation baseboard, and which is connected to a power supply path of a device targeted to be protected, and which causes a blowout when a predetermined abnormal electric power, amount is supplied. A flux is coated on a surface of the soluble conductor, and an insulation cover member is mounted on the baseboard and covers the soluble conductor. The protection element also includes a stepped portion for retaining the flux at a predetermined position in contact with the flux, and the stepped portion is formed opposite to the soluble conductor on an interior face of the insulation cover member.

Abstract: A cutout cover includes an arcuate top portion covering an insulator having a closed top and an open bottom with a slit extending therebetween. A midsection can connect the top portion to an open end adapted to access the cutout. The top portion is bell-shaped with an upper and lower dome, two opposing sides, and a slit between the sides. A fastener mechanism is attached to the two opposing sides with an aperture disposed on each of the sides for receiving a fastener.

Abstract: A safety fusible connector extends between a main feed and a tap of a power line. The connector comprises an insulated tube. A protective sleeve is mounted within an upper portion of the insulated tube. A fuse has an upper contact and a lower elongated fuse line, wherein the fuse is placed within the protective sleeve. A first component is attachable to a top end of the insulated tube for electrically clamping the upper contact of the fuse to the main feed. A second component is attachable to a bottom end of the insulated tube for electrically connecting the fuse line of the fuse to the tap. If a current fault occurs in the tap, the fuse will blow and cause the second component to disconnect the fuse line, so that the main feed can still have power.

Abstract: A fuse cutout assembly having enhanced safety features to aid in both removal and replacement of fuse tubes. The inventive assembly can be produced by making modifications to standard fuse cutout assemblies. The modifications include lengthening the trunnions of the lower contact assembly and adding reflectors as a further visual aid for positioning the lower contact portion of the fuse tube within the trunnion sockets. Additionally, a molded plastic guide placed proximate the lower contact area of the fuseholder of the cutout promotes “self guiding” of the fuseholder during replacement. Also, the pull ring is modified by the addition of protruding arcuate sections extending from a standard pull ring, the sections allowing the technician to engage the pull down ring without aiming the hook stick through the ring. Additional reflectors are strategically placed to facilitate replacement of the fuseholder.

Abstract: The circuit breaker according to the present invention has first and second terminals having favorable electric conductivity and joined to each other with solder; and a heater whose circumference is insulated installed for melting the solder and supplied with electric power from the current path separate from current paths passing through the first and second terminals; wherein the first and second terminals are separated by a spring force and insulated when the solder is melted.

Abstract: An insulator for a cutout switch and fuse assembly used in connection with an electrical power grid, including a body including a first end and a second end, a guide connector, a conductor strip, and a tool structure is located, a pivot connector is located at the second end of the body, and a mounting connector is located on the body between the first end and the second end. In an alternative embodiment, universal connectors are located at the first end and the second end. The body is manufactured by a filament winding process.

Abstract: A fuse mounting assembly includes an epoxy-bonded glass-fiber core that is surrounded by a resilient sleeve having a number of radially extending members. Attached to an end of the core is a first mounting bracket and attached to another end of the core is another mounting bracket. Each of the mounting brackets is connected to a fuse which is structured to protect a power circuit.

Abstract: An enclosed insulator assembly has a generally cylindrical polysiloxane body, a tubular Durethan® core with upper and lower terminals, Multilam™ contacts within the terminals, an arc-quenching tube, and a manually removable handle. Entrance holes in the body accommodate the coupling of external cables to the terminals. A threaded cylinder positioned on the handle's interior accommodates one of an interchangeable cutout fuse tube assembly and disconnect tube assembly and permits the assembly to be inserted into the core as the handle is positioned on the body. Both assemblies have top and bottom fittings with O-rings that prevent weather corrosion between the fittings and terminals. A grooved load interrupter is attached to the bottom fitting of the assemblies to suppress arcing when the assembly is pulled out from the body.

Abstract: A fuse mounting assembly includes an epoxy-bonded glass-fiber core that is surrounded by a resilient sleeve having a number of radially extending members. Attached to an end of the core is a first mounting bracket and attached to another end of the core is another mounting bracket. Each of the mounting brackets is connected to a fuse which is structured to protect a power circuit.

Abstract: An enclosed insulator assembly has a generally cylindrical polysiloxane body, a tubular Durethan® core with upper and lower terminals, Multilam™ contacts within the terminals, an arc-quenching tube, and a manually removable handle. Entrance holes in the body accommodate the coupling of external cables to the terminals. A threaded cylinder positioned on the handle's interior accommodates one of an interchangeable cutout fuse tube assembly and disconnect tube assembly and permits the assembly to be inserted into the core as the handle is positioned on the body. Both assemblies have top and bottom fittings with O-rings that prevent weather corrosion between the fittings and terminals. A grooved load interrupter is attached to the bottom fitting of the assemblies to suppress arcing when the assembly is pulled out from the body.

Abstract: A fuse mounting assembly includes an epoxy-bonded glass-fiber core that is surrounded by a resilient sleeve having a number of radially extending members. Attached to an end of the core is a first mounting bracket and attached to another end of the core is another mounting bracket. Each of the mounting brackets is connected to a fuse which is structured to protect a power circuit.

Abstract: Device for the protection from effects of an electric field, of the metal parts of chains of insulators of already mounted and operational high-voltage transmission lines includes: a fastening/support plate; anchoring elements to anchor the plate to the suspension yoke of the conductors of the transmission line, the anchoring elements being adjustably mounted on the plate according to at least two degrees of freedom; and at least one guard ring, which may be anchored on the plate with fastening elements. The plate has an upturned-U cross-section and its upper surface is formed by geometrically coupling with the lower surface of the suspension yoke. The anchoring elements include a pair of arms articulately, mounted on the plate; such articulation including, for each arm, a pin pivotally, mounted within seats formed in the plate perpendicularly to the longitudinal axis thereof, and a pair of holes running through the pin.

Abstract: A fuse mounting assembly includes an epoxy-bonded glass-fiber core that is surrounded by a resilient sleeve having a number of radially extending members. Attached to an end of the core is a first mounting bracket and attached to another end of the core is another mounting bracket. Each of the mounting brackets is connected to a fuse which is structured to protect a power circuit.

Abstract: A fault condition monitoring apparatus for use with a fuse cutout includes a housing operable to be supported by the fuse cutout. The housing has first and second contacts operable to make electrical contact with fuse contacts on the fuse cutout when the housing is supported by the fuse cutout. A current sensor is mounted inside the housing and is connected to the first and second contacts. A signaling device is coupled to the current sensor and is operable to cause a signal to be produced when current sensed by the current sensor meets a criterion.

Abstract: A mounting for a circuit interrupter is provided that facilitates the easy removal and insertion of the circuit interrupter. The mounting includes upper and lower terminal and support arrangements that cooperate with upper and lower device mounting studs of a circuit interrupter. The device mounting studs also function as electrical circuit connection points to connect the circuit interrupter in an electrical circuit via respective upper and lower contact assemblies of the mounting. The upper and lower contact assemblies include resilient retention facilities for providing suitable electrical contact forces when engaged with the device mounting studs. The upper and lower terminal and support arrangements retain the circuit interrupter within the mounting and are selectively operable to release the circuit interrupter for removal from the mounting.

Abstract: A fuse block for cabinet mounting provides a shaft that may exit a side of the cabinet to be received by a handle mounted on that side. A finger attached to the inner cabinet door provides for an interlock by engaging with a bolt communicating with the shaft preventing inadvertent opening of the cabinet when the fuse block is connected to power and/or connecting the fuse block to power when the cabinet door is open.

Abstract: A mounting for a circuit interrupter is provided that facilitates the easy removal and insertion of the circuit interrupter. The mounting includes upper and lower terminal and support arrangements that cooperate with upper and lower device mounting studs of a circuit interrupter. The device mounting studs also function as electrical circuit connection points to connect the circuit interrupter in an electrical circuit via respective upper and lower contact assemblies of the mounting. The upper and lower contact assemblies include resilient retention facilities for providing suitable electrical contact forces when engaged with the device mounting studs. The upper and lower terminal and support arrangements retain the circuit interrupter within the mounting and are selectively operable to release the circuit interrupter for removal from the mounting.

Abstract: A fuse handling device for use with a fuse unit having a pair of contacts between which a fuse terminals which act as switching contacts may extend in use. The handling device comprises an actuating lever operable into a first position and a second position, a charging means operably connected to the actuating lever and a drive means operably connected to the charging means. The handling device in use is mounted on the fuse unit. The drive means attaches to the fuse and operation of the actuating lever into the first position charges the charging means to causes the drive means to extract the fuse from the pair of contacts and operation of the actuating lever into the second position charges the charging means to cause the drive means to insert the fuse into the pair of contacts. The fuse moves in a direction parallel to a plane of its switching contacts.

Abstract: The power circuit breaker has an igniter unit disposed in a cylindrical wall formed in a main housing. A holder is disposed in the cylindrical wall so as to oppose to the igniter unit. The holder has a boss engaged with the cylindrical wall, and a fuse element is held by the holder. Each end of the fuse element is electrically connected to one of a pair of interconnection terminals disposed in the main housing. The holder is locked by a locking lance formed in the main housing when each end of the fuse element has engaged with one of the interconnection terminals. The holder rests on the locking lance when the fuse element has been released from the interconnection terminals after activation of the igniter unit. The fuse element is engaged with and stopped by an insertion hole of the holder.

Abstract: An actuating device (60) operated by a hookstick (4) is attached to a manually operated fused cutout switch (2) or a oil circuit recloser switch (14). The device (60) comprises a cantilever (62) with a pair of opposing hook-shaped receptacles (70, 72) for receiving a hookstick (4) that is used to alternatively open or close the switch. A method of actuating a manually operated switch is disclosed.

Abstract: A non-venting current limiting fuse for mounting in a cutout comprises a high current fuse component and a low current fuse component housed in separate compartments of a housing and connected in series. Interruption of a low current overload results in operation of the low current fuse component only, with the high current component being unaffected. The low current fuse component is removable from the housing such that when a low current overload situation exists, the low current fuse component can be simply removed and replaced without the need for replacement of the more costly high current fuse component.

Abstract: An actuating device operated by a hookstick is attached to an existing ring on a manually operated fused cutout switch or oil circuit recloser switch. The device comprises a cantilever and a clamp for attaching the cantilever about the existing ring. The cantilever a pair of lever arms, each having a hook-shaped receptacle for receiving a hookstick that is used to alternatively open or close the switch. Methods of actuating a manually operated recloser and lock-out switch and modifying such a switch to facilitate manual operation are disclosed.

Abstract: An actuating device operated by a hookstick is attached to a manually operated oil circuit recloser switch. The device comprises a cantilever and an affixed switch lever. The cantilever includes a pair of lever arms, each having a hook-shaped receptacle for receiving a hookstick that is used to alternatively open or close the switch. Methods of actuating a manually operated switch in a recloser and lock-out device and modifying such a switch to facilitate manual operation are disclosed.

Abstract: An actuating device operated by a hookstick is attached to an existing ring on a manually operated fused cutout switch or oil circuit recloser switch. The device comprises a cantilever and a clamp for attaching the cantilever about the existing ring. The cantilever a pair of lever arms, each having a hook-shaped receptacle for receiving a hookstick that is used to alternatively open or close the switch.

Abstract: An improved fuse block-out device is disclosed that includes a fuse block-out device that includes a first portion shaped to be received by a fuse block and a second portion shaped to securely engage a fuse. When a fuse is removed from the fuse block, the first portion of the fuse block-out device is inserted into the fuse block, and the removed fuse is inserted into the second portion of the fuse block-out device. In this way, the fuse block-out device reduces accidental electrical shock and prevents accidental replacement of the removed fuse. Because the removed fuse is securely engaged, the fuse block-out device controls the location of the removed fuse.

Abstract: A current responsive latching apparatus may be employed in a dropout fuseholder or other electrical component for retaining the component in a current-carrying position and disconnecting and isolating the electrical component upon the occurrence of an overcurrent of a predetermined magnitude. The apparatus includes a current path through the component, including a current-carrying stud or conductor, a portion of which extends outside the component for releasably engaging a support member. A latching apparatus, which may include an actuating member of memory allow or a bimetallic material, engages the conductor to retain the support member in a supporting position beneath the electrical component. The apparatus may further include a heater element in the current path to ensure that the actuation member is heated to the temperature necessary to cause it to change shape and release the conductor upon the presence of an overcurrent.

Abstract: A circuit-interrupting device for electrical power distribution and transmission systems is provided having improved handling provisions for removal and installation with respect to conventional mountings. The handling provisions permit the circuit-interrupting device to pivot about the lower hinge of the mounting before the circuit-interrupting device is lifted out of the mounting via a handling tool. This permits the dimensions of the circuit-interrupting device to be greater than conventional circuit-interrupting devices. For example, in a preferred embodiment, the circuit-interrupting device includes exhaust diverter structure which directs exhaust away from the mounting, the exhaust diverter structure extending beyond the maximum dimensions which allow the circuit-interrupting device to be directly lifted out of the mounting hinge, i.e. the exhaust diverter structure interferes with the mounting if the circuit-interrupting device is lifted in a direction out of the mounting.

Abstract: A current-limiting dropout fuseholder includes multiple current paths through the fuse body. A primary current path includes a high current fusible element. A secondary current path in parallel with the primary path includes a triggering conductor that extends outside the fuse body and is connected to a moveable support. The second current path further includes a first spark gap for severing the triggering conductor upon the occurrence of a fault and the shifting of the fault current from the primary current path to the second current path. A second spark gap formed between the primary and the second current paths ensures that the fault current flows across the first spark gap for a time sufficient to sever the triggering conductor, thereby ensuring that dropout will occur.

Abstract: Fuses for the potential transformers (PTs) in medium voltage switchgear are mounted in fuse assemblies which are reciprocated within the switchgear enclosure independently of the transformers they protect between a connected position in which the fuse assemblies engage stabs at the rear wall of the enclosure and a retracted position adjacent a door at the front of the enclosure through which the fuses are inserted and removed while the fuse assemblies remain within the enclosure. The fuse assemblies include insulative tubes having first releasable contacts at a distal end which engage the stabs and second releasable contacts which engage fixed contacts connected to the transformers and spaced from the rear wall. The insulative tubes are mounted on a carriage which reciprocates between the connected and retracted positions. An interlock prevents opening of the door except where the carriage is in the retracted position and blocks movement of the carriage with the door open.

Abstract: A low-exhaust composite drop-out assembly is provided that is utilizable in a standard cutout mounting in electrical power distribution systems. The composite drop-out assembly includes current-limiting and low-current clearing sections and is easily removable from mounting for servicing. The sections are efficiently arranged in a side by side configuration.. The low-current clearing section includes a fuse-robe assembly having a replaceable fuse cartridge. Accordingly, the low-current clearing section is simply and economically renewable for reuse whether or not the current-limiting section has operated. Further, the current-limiting section need not be replaced if only the low-current clearing section operated in response to overcurrent in a low range. Additionally, the sections are separable so that the low-current clearing section can be reused after simple refusing even when the current-limiting section has operated.

Abstract: A universal fuse holder and cut-out is provided with a slot having a length L and width W aligned with the fuse tube and engageable with the fuse tube and engageable by a projecting arm or member of a hot switch stick so as to enable safe and expedient maintenance and service, particularly in high wind and storm conditions. One contact assembly is lengthwise and rotatably mounted to accommodate long and short fuse tubes and different manufacturer styles of switch assembly.

Abstract: A current-limiting device is provided having a low profile configuration (generally flat polyhedron) that defines a cavity of predetermined dimensions and an elongated circuitous path through the cavity. The device also includes provisions for supporting a current-limiting fusible element along the path. The cavity is filled with a pulverulent arc-quenching filler material. In one specific arrangement, the path of the fusible element is defined by one or more U-shaped sections substantially spanning the length or width of the cavity. The fusible element is arranged in a predetermined geometry to include a length of the fusible element that is longer than the overall straight-line path via a configuration of steps or bends along its length.

Abstract: A universal fuse holder and cut-out safety adapter. The adapter is adapted to be secured to the fuse tube and has a slot having a length L and a width W for engagement by the projecting arm of a hot stick switch.

Abstract: An improved load break disconnecting device is disclosed, comprising a conductive portion having a non-gassing fuse, a fuse cartridge having first and second ends and enclosing said fuse, a conducting hinge assembly and conducting stationary contact means, and a non-conducting arc extinguishing sleeve with latch means for latching the sleeve in a non-covering position until the switch is closed and biasing means for snapping the sleeve into an arc-extinguishing, covering position when the switch is opened.

Abstract: A current responsive latching apparatus may be employed in a dropout fuseholder or other electrical component for retaining the component in a current-carrying position and disconnecting and isolating the electrical component upon the occurrence of an overcurrent of a predetermined magnitude. The apparatus includes a current path through the component, including a current-carrying stud or conductor, a portion of which extends outside the component for releasably engaging a support member. A latching apparatus, which may include an actuating member of memory allow or a bimetallic material, engages the conductor to retain the support member in a supporting position beneath the electrical component. The apparatus may further include a heater element in the current path to ensure that the actuation member is heated to the temperature necessary to cause it to change shape and release the conductor upon the presence of an overcurrent.

Abstract: An electrical cutout with a modular product design is provided with a constructional configuration for the insulator wherein the insulator is light in weight, has sufficient mechanical strength, can be readily injection molded, and wherein the creep distance is statistically maximized. The electrical cutout has an insulator, an upper and lower line terminal assembly, and a fuse assembly. The insulator has an elongated central stem portion defining a longitudinal direction, and a plurality of longitudinally spaced apart skirts mounted to the stem portion and so as to lie in respective transverse planes which are perpendicular to the longitudinal direction. The elongated central stem portion of the insulator has a non-solid cross-sectional configuration.

Abstract: A switch, for an electrical transmission line, can be used as a vertically mounted cut out or as an in-line switch. The switch has an insulator, mounting bars at either end, and a first and second brackets extending from the mounting bars. Brackets are configured to receive a fuse element, which can be of known construction. A first bracket includes a pair of bracket elements that defines slots for receiving pivot lugs of the fuse element. To enable the switch to be used either vertically as a cut out or horizontally as an in-line switch, the bracket elements are moveably, preferably rotatably, mounted to the first bracket. The bracket elements can then be located so that the slot is always at least partially directed upwardly. Then, for either use, the fuse element will always be retained by its pivot lugs in the slot. To enable the switch to be mounted as an in-line switch, the insulator can be provided with a relatively narrow central portion to its body and a removable clamp.

Abstract: A fused cutout for a power distribution system, which cutout includes an insulating member (2) having two opposed ends and a recess located between the two opposed ends, a fuse (12) defining a current path and having an element for interrupting the current path when current flowing through the path exceeds a selected value, a first conductive support structure (6) connected at a first end of the insulating member (2), conductively connected to a first end of the current path and connectable to a source of electrical power (14), a second conductive support structure (8) connected at a second end of the insulating member (2), conductively connected to a second end of the current path and connectable to a consumer of electrical power (16), each conductive support structure (6,8) producing an electric field when connected to the source of electrical power, and a mounting bracket assembly (4) for supporting the fused cutout and including a conductive member (30) secured in the recess of the insulating member (2).

Abstract: A fuse tube is provided for cutout and power fuse assemblies. The fuse tube has a body with a red retroreflective portion and a white retroreflective portion. When conducting the red portion lies above the white portion. When the fuse blows, the white portion lies above the red portion. By observing whether the fuse tube has red over white or white over red, the condition of the fuse is determined. If the orientation is red over white, the fuse is all right. If the orientation is white over red, the fuse is dead, and needs to be replaced.

Abstract: A rain shield for a circuit-interrupting device is provided that includes a housing for attachment to the circuit interrupter adjacent an exhaust outlet of the circuit interrupter. The rain shield prevents the ingress of moisture while providing a path for the exhaust gases of the circuit interrupter. The rain shield is selectively attachable to the circuit interrupter and is reusable. In one arrangement, the rain shield includes a housing which is generally cylindrical and has an inlet opening at a first end for cooperation with the exhaust outlet of the circuit interrupter. At a second opposite end of the housing, an outlet is defined that includes a predetermined pattern of openings. A centrally disposed plate is provided adjacent the outlet and functions as a drip cap such that moisture in the form of precipitation that enters the outlet of the rain shield is prevented from entering the inlet opening adjacent the circuit interrupter.

Abstract: An improved, integrally cast, synthetic resin insulator (22) especially adapted for use in an electrical cutout device (20) is provided which can be readily fabricated and gives greatly enhanced beam strength and arc track resistance characteristics. The preferred insulator (22) is cast using an epoxy resin such as bisphenol A filled with a relatively large quantity of glass beads and hydrated alumina. The filler fraction contributes to lowered viscosity, deaerability and improved settling properties while the resin is in an uncured state, and moreover enhances the arc track resistance and mechanical strength of the resin system after curing. The preferred insulator (22) is cast to present a longitudinal bow giving the insulator (22) an arcuate central axis. Further, the periphery of the insulator (22) is formed with a series of superposed, generally oval-shaped in cross-section, outwardly flaring skirts (30) interconnected by smooth transition regions (32) free of stress-inducing sharp corners.

Abstract: An ejecta trap for a drop out expulsion fuse of the type comprising an elongate insulating body with a conductive head fitting and tail socket. The tail socket is pivotally connected to the tail fitting and the head and tail fittings are adapted to electrically and mechanically engage respective head and tail terminals. A fuse means is connected within the body between the head and tail fittings. The ejecta trap is pivotally mounted on the tail terminal such that it may be swung between an in-use position immediately below the tail fitting where it collects ejected fuse means material and another position.

Abstract: A switchgear assembly for an electrical apparatus capable of improving operability thereof to a practical extent, as well as reducing not only installation area or space for various devices to be disposed below the switchgear but also the weight of the switchgear itself. The switchgear assembly such as a disconnecting switch assembly, fuse assembly or the like is interposed between a bus bar supported through a first support insulator on the top end of a vertical pole, and an electrical apparatus connected to the bus bar. The disconnecting switch assembly or fuse assembly comprises a movable contact pivoted at its one (lower) end to a pole mounted second support insulator for rotary motion in a vertical plane and engageable at the other (upper) end directly with the bus bar or with a fixed contact or fuse retainer supported on the bus bar by a fastening member. The other (upper) end of the movable contact or fuse is fastened to the bus bar completely independent of the pole.

Abstract: An open fuse cutout has a built-in lightning arrester. A supporting insulator has an attachment hole extending substantially perpendicularly to the axis thereof with the lightning arrester element fixedly fitted in the attachment hole. The lightning arrester element has a charging electrode held in abutment against either one of upper and lower electrodes, and a grounding electrode confronting a grounding member across a spark gap.

Abstract: An open fuse cutout has a built-in lightning arrester. The open fuse cutout includes a supporting insulator with a protective cap fixed to an upper end thereof and containing the lightning arrester disposed laterally or vertically. The lightning arrester element has a charging electrode confronting an upper electrode across a first spark gap and a grounding electrode confronting a grounding member across a second spark gap.