Abstract: An improved triggered arc flash arrester includes a shield apparatus disposed within an interior of an evacuated envelope and includes a first shield element and a second shield element. A plurality of conductors are partially disposed within the interior and are separated from one another by a gap. A first element of the shield apparatus is situated adjacent the envelope and is structured to protect the envelope from damage due to the high temperature plasma that results from an arc across the gap. A second element of the shield apparatus is interposed between the gap and at least a portion of the first element and is structured to protect the at least portion of the first element from damage due to an arc across the gap.

Abstract: A self-pressurized arc diverter includes a vessel configured to enclose a fusible member disposed in a conductor and a pressure-activated arc diverter. The pressure-activated arc diverter is configured to provide access to a preferred arc path when actuated by pressure in the vessel caused by an arc that is created when the fusible member opens.

Abstract: Arc fault detection method and apparatus employ an impedance-based current sensor to provide a sensing signal indicative of current through a conductor. The impedance-based current sensor diverts high frequency components of current through the conductor and converts the high frequency components into an arc fault signal.

Abstract: A self-pressurized arc diverter includes a vessel configured to enclose a fusible member disposed in a conductor and a pressure-activated arc diverter. The pressure-activated arc diverter is configured to provide access to a preferred arc path when actuated by pressure in the vessel caused by an arc that is created when the fusible member opens.

Abstract: Arc fault detection method and apparatus employ an impedance-based current sensor to provide a sensing signal indicative of current through a conductor. The impedance-based current sensor diverts high frequency components of current through the conductor and converts the high frequency components into an arc fault signal.

Abstract: An arc fault and/or ground fault circuit interrupter includes an operating mechanism structured to open and close separable contacts, a trip mechanism cooperating with the operating mechanism to trip open the separable contacts, a test button structured to test the operating mechanism, an indicator, and a controller structured to configure a setting of the circuit interrupter and operate the indicator to indicate the setting in response to an actuation of the test button.

Abstract: An arc fault and/or ground fault circuit interrupter includes an operating mechanism structured to open and close separable contacts, a trip mechanism cooperating with the operating mechanism to trip open the separable contacts, a test button structured to test the operating mechanism, an indicator, and a controller structured to configure a setting of the circuit interrupter and operate the indicator to indicate the setting in response to an actuation of the test button.

Abstract: An improved circuit breaker includes an arc extinction system having one or more insulators that generates a desirable gas in the presence of an arc. The exemplary circuit breaker includes gas-generating insulators disposed at three sides of a stationary contact and an arc chute at a fourth side of the stationary contact. The gas promotes the desirable extinction of the arc in a number of exemplary fashions. The presence of the gas on three sides of the stationary contact can resist movement of the arc toward the gas, thereby substantially limiting movement of the arc in a direction other than toward the arc chute. The gas can remove heat from the arc, thereby promoting deionization of the plasma by forming neutral molecular species at a lower temperature state. The presence of the gas can reduce the concentration of ions and electrons within the interior of the circuit breaker and can increase the pressure within the circuit breaker, and these also facilitate extinction of the arc.

Abstract: An improved circuit breaker includes a case, a movable arm, and a bumper retained within a receptacle formed on the case. The bumper is retained in the receptacle by a number of spaced ribs that engage certain portions of the bumper yet permit deformations of other portions of the bumper into an expansion region. By employing a bumper made of a material having a low coefficient of restitution, deformation of the bumper tends to dissipate the energy of a removable arm impacting the bumper. The bumper can be installed, removed, and replaced substantially without requiring the use of an adhesive. The movable arm engages the bumper on a corner of the bumper to provide the bumper with an effectively progressive spring rate.

Abstract: Arcing faults in an electric power system are detected by sensors powered by the light generated by the arcing even in the presence of background light. The sensors have one or more first photovoltaic cells energized by light passed through a first filter having a passband which includes a characteristic wavelength of the arcing material to generate a sensed light electrical signal. One or more second photovoltaic cells are energized by light filtered by a second filter having a passband not including the characteristic wavelength to generate a background light electrical signal. These two electrical signals are applied in opposition to an LED which is turned on when arcing is present. The light signal from the LED is transmitted through an optic fiber to a photoelectric circuit, which generates an arcing signal when energized. The LED may be biased toward the on condition by unfiltered additional photovoltaic cells.

Abstract: Arcing faults in an electric power system are detected by sensors powered by the light generated by the arcing even in the presence of background light. The sensors have one or more first photovoltaic cells energized by light passed through a first filter having a passband which includes a characteristic wavelength of the arcing material to generate a sensed light electrical signal. One or more second photovoltaic cells are energized by light filtered by a second filter having a passband not including the characteristic wavelength to generate a background light electrical signal. These two electrical signals are applied in opposition to an LED which is turned on when arcing is present. The light signal from the LED is transmitted through an optic fiber to a photoelectric circuit, which generates an arcing signal when energized. The LED may be biased toward the on condition by unfiltered additional photovoltaic cells.

Abstract: A current limiting PTC device (10) has two electrodes (14) with a thin film of electric conducting polymer material (20) disposed between the electrodes, the polymer material (20) having superior flexibility and short circuit performance, where the polymer material contains short chain aliphatic diepoxide, conductive filler particles, curing agent, and, preferably, a minor amount of bisphenol A epoxy resin.

Abstract: Arcing faults in electric power systems, such as switchgear, are detected by gathering light from components in the system and splitting the gathered light into two beams. The first beam is passed through a first narrow band filter to extract a wavelength characteristic of arcing in the material of the selected component, such as the copper in the switchgear conductors. The second beam is passed through a second filter having a narrow bandwidth, not including the characteristic wavelength. The extracted light signals are converted to a sensed light electrical signal and a background light electrical signal, respectively, by photodiodes and compared. If the sensed light electrical signal exceeds the background light electrical signal by a selected threshold, an output device such as a trip solenoid is actuated.

Abstract: A novel multi-layer current limiting PTC polymer device comprising at least two layers of a conductive polymer composition with electrodes attached thereto characterized by having a low contact resistance and a method of producing the same. The invention provides for the selective treatment of portions of the surface of each layer of the conductive polymer composition by at least one of plasma/corona etching and plasma sputtering/plasma spray to create a site for attachment of the electrodes resulting in a low contact resistance. The electrical devices of the invention are particularly useful in circuit protection applications.

Abstract: Low voltage current limiting fuses wherein the conventional fusible element is replaced. The fuses of the invention are resettable manually or automatically such that the fuse need not be physically replaced following a fault current or overload current occurrence in the external circuit in which the fuse is incorporated.

Abstract: A novel current limiting PTC polymer device and methods of making the same comprising a current limiting polymer composition with porous electrodes interfaced therewith such that a low contact resistance results using a combination of (1) extrusion attachment of the current limiting polymer composition to the porous electrodes, (2) careful selection of the electrode materials in view of the conductive filler and/or conductive metal particles in the current limiting polymer composition, and (3) plasma treatment of the attachment surfaces of the current limiting polymer composition preceding and/or during the extrusion attachment process. The invention provides for the selective treatment of portions of the surface of the current limiting polymer composition by at least one of plasma etching and metallizing to create attachment surfaces for extrusion attachment of porous electrodes resulting in a low contact resistance, mechanical stability and a reduced potential for arcing in the electrode/polymer interface.

Abstract: Electrical devices based on current limiting PTC polymer devices, and in particular, electrical circuit protection devices containing a current limiting PTC polymer device composed of a current limiting polymer composition in combination with suitable electrodes and a low inductance shunt to protect the current limiting polymer composition from exceeding its breakdown field strength. Specifically, electrical devices containing a current limiting polymer composition in combination with suitable electrodes and a low inductance shunt in the form of a ribbon shunt, i.e. a flat sheet of conductive material folded over on itself.

Abstract: A novel current limiting PTC polymer device comprising a conductive polymer composition with electrodes attached thereto characterized by having a low contact resistance and a method of producing the same. The invention provides for the selective treatment of portions of the surface of the conductive polymer composition by at least one of plasma/corona etching and plasma sputtering/plasma spray to create a site for attachment of the electrodes resulting in a low contact resistance. The electrical devices of the invention are particularly useful in circuit protection applications.

Abstract: A high voltage current limiting fuse has improved low fault current interruption due to an end-sealed sleeve separating a fusible length from pulverulent sand in a casing of the fuse while permitting venting of gas and vaporized metal plasma due to melting and arcing at the fusible length. The fuse can have one or more fusible elements, of which at least one, preferably each one, is surrounded along at least a selected portion along its length by a polytetrafluoroethylene polymer, fluoroethylene polymer, or derivatives thereof, which can be heat shrinkable or not. The sleeve is sealed so as to allow escape of gases upon arcing from the sleeve but to prevent pulverulent materials from penetrating within the sleeve. The sleeve seals are either melted and crimped together with the fusible element, heat shrunk down onto the fusible element, or taped over the fusible element so as to leave a gap small enough to exclude the pulverulent material while venting gas and plasma.