Abstract: A rupture reduction system for fluid-immersed electrical equipment includes a turret for mounting of a bushing. The turret is expandable in volume in response to a surge in pressure of the fluid in the turret. The expansion volume can be provided by an expandable section of the turret, which may include a bellows.

Abstract: An encapsulated fuse for power distribution systems and method for producing such fuses is provided. A fuse includes a body with opposing terminals. A corona shield is generally coaxial with the fuse and substantially extends the full length of the fuse body. The corona shield is electrically coupled at its first end with a first fuse terminal. The second end of the corona shield has a slightly larger cross-section than the first end to provide electrical isolation from the second fuse terminal. The fuse and attached corona shield are molded in an encapsulating material.

Abstract: A fuse and filter arrangement having a polymer fuse apparatus that provides bypass fuse protection. A polymer bypass fuse includes of an electrical conductor wherein a portion of the conductor is surrounded by an internal electrode, which is then surrounded by a layer of polymeric positive temperature coefficient (PTC) material, which is then surrounded by a conductive material similar to that of the internal electrode. The fuse and filter arrangement includes a plurality of in-line and bypass fuses combined with a differential and common mode filter, which itself consists of a plurality of common ground conductive plates maintaining first and second electrode plates between the various conductive plates, all of which are surrounded by a material having predetermined electrical characteristics to provide fail safe filter and circuit protection.

Abstract: The present invention relates to a polymer fuse apparatus that provides bypass fuse protection. A polymer bypass fuse is comprised of an electrical conductor wherein a portion of the conductor is surrounded by an internal electrode, which is then surrounded by a layer of polymeric positive temperature coefficient (PTC) material, which is then surrounded by a conductive material similar to that of the internal electrode. Various hybrid combinations are also contemplated where in-line and/or bypass fuses are combined with other circuit components. One example is, a plurality of in-line and bypass fuses combined with a differential and common mode filter, which itself consists of a plurality of common ground conductive plates maintaining first and second electrode plates between the various conductive plates, all of which are surrounded by a material having predetermined electrical characteristics to provide fail safe filter and circuit protection.

Abstract: The present invention relates to a polymer fuse apparatus that provides bypass fuse protection. A polymer bypass fuse is comprised of an electrical conductor wherein a portion of the conductor is surrounded by an internal electrode, which is then surrounded by a layer of polymeric positive temperature coefficient (PTC) material, which is then surrounded by a conductive material similar to that of the internal electrode. Various hybrid combinations are also contemplated where in-line and/or bypass fuses are combined with other circuit components. One example is, a plurality of in-line and bypass fuses combined with a differential and common mode filter, which itself consists of a plurality of common ground conductive plates maintaining first and second electrode plates between the various conductive plates, all of which are surrounded by a material having predetermined electrical characteristics to provide fail safe filter and circuit protection.

Abstract: The present invention relates to a polymer fuse apparatus that provides bypass fuse protection. A polymer bypass fuse is comprised of an electrical conductor wherein a portion of the conductor is surrounded by an internal electrode, which is then surrounded by a layer of polymeric positive temperature coefficient (PTC) material, which is then surrounded by a conductive material similar to that of the internal electrode.Various hybrid combinations are also contemplated where in-line and/or bypass fuses are combined with other circuit components. One example is, a plurality of in-line and bypass fuses combined with a differential and common mode filter, which itself consists of a plurality of common ground conductive plates maintaining first and second electrode plates between the various conductive plates, all of which are surrounded by a material having predetermined electrical characteristics to provide fail safe filter and circuit protection.

Abstract: An electrostatic discharge ground path for a fuse installable in a fuse holder includes an area of metallization on at least one insulating surface of the fuse extending from an exposed surface of the fuse to a contact area within the fuse holder.

Abstract: An encapsulated fuse assembly with a corona shield for use in high voltage underground power distribution systems. The fuse assembly includes a fuse encapsulated within an insulative outer housing. The outer surface of the fuse is coated with an electrically conductive material which is in electrical connection with one of the fuse terminals and extends along the outer surface of the fuse body to a point intermediate the other terminal leaving a portion of the fuse body not coated with the conductive material. Preferably, at least the terminal of the fuse not in contact with the conductive material is enveloped by an electrically conductive insert disposed within the insulative outer housing which along with the conductive coating establish an effective corona shield around the fuse without providing an alternate electrical circuit between the fuse terminals.

Abstract: A device for isolating a hazardous connection on a circuit board includes an elongated enclosure having a bore extending therethrough and a slot extending longitudinally from a first end of the enclosure. A component such as a fuse, having leads on both ends, is advanced through the bore until one of the leads, bent orthogonally to the enclosure, becomes secured in a distal end (pocket) of the slot. The length of the enclosure is determined such that when the lead is engaged in the distal end of the slot, a portion of the enclosure extends over the lead to isolate any connections made by that lead from external contact. In a preferred embodiment, a second slot is provided on the other end of the enclosure wherein a second lead may then be bent orthogonally to the device, and parallel with the first lead, to isolate both leads of the component. The protective device is advantageously transparent to allow for monitoring of the component being isolated.

Abstract: A fuse assembly including a housing and a fuse element which fuses open for protection against overcurrent or short-circuit current flows. The fuse assembly also includes reflecting means such as metal polished surfaces for reflecting radiation rays generated from the fuse element back to the fuse element. The reflecting means may be formed from separate parts interposed between the fuse element and the inner wall of the housing. Alternatively, the reflecting means may be formed by applying a metal plating on a surface of an inner wall of the housing to give a mirror-like appearance to the surface.

Abstract: A fine ozone corrosion resistant fuse wire is supported between conductive terminals which are, in turn, supported on and spaced apart by rigid insulator spacing means so that the fuse wire is extended. Insulator shield means is placed over the fuse wire over a substantial length of the insulator spacing means to shield the insulator spacing means from vaporized filament material to ensure that in all possible fuse failure modes that the circuit is completely broken but including a portion is unshielded so that vaporized material will plate on to the insulator to permit quick detection of a failed fuse. The rigid insulator spacing means may take the form of a rod generally parallel to the fuse with the terminals as end caps fitting over the rod or it may take the form of a tubular member fitting around portions of the terminals and confining the fuse internally, preferably so that oxygen cannot readily reach the fuse when it is used in a concentrated oxygen atmosphere.

Abstract: Semiconductive paint is applied to a narrow strip on the inside surface of an insulating enclosure for a submersible fuse. The enclosure is generally watertight. The semiconducting paint marginally overlaps two isolated regions of electrically conducting paint. The combination of the conducting paint and semiconducting paint covers the entire inner surface of the enclosure and acts cooperatively to prevent or reduce corona therein. At the place of overlap, rounded ridges are provided for shielding the relatively sharp interface corner of the conductive paint on the inside surface of the electrically insulating material to reduce the corona at that relatively critical point. A flowable rubber gasket is provided for insertion between two separable portions of the enclosure. The gasket not only provides watertight sealing for the enclosure when completely assembled but has a bead on the inside surface thereof which shields the corners of the two portions of the enclosure to reduce the corona effects thereat.

Abstract: Two housing halves are joined to form a housing surrounding an electrical fuse, a sealing gasket being provided at the joint between the housing halves. A corona shield is embedded wholly within each housing half, each shield terminating on its respective side of the gasket so that the ends thereof are closely adjacent but yet spaced apart with a portion of the gasket therebetween. Each shield is electrically connected to a respective end of the fuse. The gasket has an inner cylindrical wall provided with spaced ribs. The cylindrical wall closely engages the fuse within the housing and small elongated openings are defined along both sides of each rib. A vent assembly in one of the housing halves selectively opens and closes the housing interior to the ambient dependent upon the internal housing pressure.