Abstract: An electrical arc extinguishing chamber designed to be placed facing separable contacts of a switchgear apparatus and to extinguish the arc generated by separation of the contacts comprises two side walls facing one another and a plurality of spaced apart plates arranged between the side walls and secured by the side walls. The side walls have a stratified composite structure with at least two layers. The layers comprise a polyamide fabric impregnated with thermosetting resin. The chamber thus obtained has advantageous breaking strength properties. The edges of the side walls do not present any dielectric weakness points. The chamber is particularly suitable for low-voltage switchgear of high power ratings.

Abstract: A magnetic core assembly and method of assembling a magnetic core assembly. The core assembly includes laminated magnetic core tightly clamped together by a pair of unitized flanged clamps. Each unitized flanged clamp has a generally flat surface and a peripheral flange. The generally flat surface defines at least one opening for receiving a coil and a number of holes adjacent the opening for receiving assembly hardware. The core is assembled by placing a first one of the two unitized flanged clamps, flange down on a generally horizontal work surface. Alignment pins are placed in one or more of the assembly hardware apertures adjacent the coil opening. The segments of the first core lamination are slidably placed on the alignment pins such that they lie on the flat surface of the first unitized flange clamp. The segments of each remaining core lamination are slidably placed on the alignment pins until the required number of laminations have been installed.

Abstract: The present invention provides an accessory module for monitoring and controlling the status of a circuit breaker. The accessory module attaches to the side of a circuit breaker and has a mechanism similar to the mechanism in a circuit breaker. The mechanism has multiple positions that correspond to multiple states of a circuit breaker. Actuators transform relatively large-scale motions of the mechanism into small-scale motions and transfers these to buttons on switches. Depressing these switches depending on the position of the mechanical assembly makes and breaks circuits that are in communication with a remote site. The invention provides a circuit board designed specifically to hold and locate the switches and actuators and provide tracings that can withstand high currents. The invention further provides a terminal plug having a pull tab which can be grasped to remove an otherwise inaccessible terminal plug.

Abstract: A switchboard for mounting and supplying electrical power to a plurality of circuit breakers has all the breakers are mounted on one side of a vertical power stack. The power stack has vertical buses to which the breakers are connected. Insulators and spacers provide air ventilation paths through the power stack. The main bus connecting members on the other side of the power stack from the breakers and are spaced apart vertically to allow for improved heat dissipation. By using vertical bus connectors, the bus connecting members may be connected to through bus connectors at any height on the back of the switchboard. The main bus connecting members are in a vertical chimney for improved heat dissipation. The circuit breaker at the highest location (the “A” phase) has the highest temperature and in the present invention, the main bus connecting member for the A phase is in the highest position to place it closest to the heat source and thereby improve the heat conduction away from the breakers.

Abstract: A system to detect arcing faults in an electrical distribution system with a line conductor connected to a utility power transformer. The system monitors the rate of change of electrical current in the line conductor and produces a signal which represents the rate of change. The system produces a pulse each time the rate-of-change signal exceeds a selected threshold, filters the rate-of-change signal and/or the pulses to substantially eliminate a signal or pulse which represents changes in the electrical current outside a selected frequency range, monitors the remaining pulses to detect when the number of pulses that occur within a selected time interval exceeds a predetermined threshold, and generates an arc-fault-detection signal in response to the occurrence of a number of pulses which exceed the threshold within the selected time interval.

Abstract: A linkage assembly for a double throw safety switch including a frame connected to a first slider plate and a second slider plate. The first and second slider plates are moveably connected to the frame by guides in the form of slots which cooperate with slider supports on the frame. The profile of the slots define a range of movement of the slider plates. A driver arm is used to effect simultaneous movement of the slider plates either toward or away from a central portion of the driver arm. A first follower arm which controls a first single throw switch, and a second follower arm which controls a second single throw switch, are also connected to the frame by a spline coupling. The first follower arm includes a slider support which cooperates with a guide, again a slot, in the first slider plate. Similarly, the second follower arm includes a slider support which cooperates with a guide in the second slider plate.

Abstract: The present invention relates to a transformer having a conductive element spiraling along the length of an insulated wire of the coil. When formed into plurality of adjacent turns, the conductive element couples one of the plurality of turns with another of the plurality of turns. The conductive element increases the series capacitance of the transformer circuit. A resistive element may also spiral along the length of the insulated wire to couple one of the plurality of turns with another of the plurality of turns. The resistive element not only increases the series capacitance of the transformer, but also increases the series conductance of the transformer circuit. The increase in the series resistance increases the dampening of the switching resonance.

Abstract: A protective containment apparatus for preventing damage to expensive components of an assembly due to the failure of an electronic component in a nearby potted circuit which is known to fail catastrophically. The containment apparatus can employ a resilient material 38 placed around the at-risk electronic component 34 prior to potting the circuit. The resilient material 38 absorbs the expanding gases and fragmented parts of the at-risk component 34 which are expelled during the catastrophic failure. The cushioning effect of the resilient material 38 prevents the fragments and parts of the potting material from becoming projectiles that can damage any nearby components of the assembly. The containment apparatus can also employ a restrictive material 42 placed around the at-risk component 34 prior to potting the circuit.

Abstract: A remotely operable switch actuation module for retrofitting a manually operated disconnect switch. The switch actuation module includes a linear operator which produces a linear movement in response to an external signal and a mechanical interface shaft which translates the linear movement into rotational movement required by the switch operating mechanism to change the ON or OFF state of the disconnect switch. The ends of the mechanical interface shaft are provided with engagement means complementary to the engagement means provide on switch operating mechanism pivot shaft and the operating arm of the manually operated disconnect switch. Therefore, the mechanical interface permits the switch operating mechanism to be engaged by either the remote switch actuation module or the manual operating arm. The switch actuation module also includes a switch status indicator which produces an electric signal indicating the ON or OFF state of the disconnect switch.

Abstract: A weatherproof enclosure 10 with a side hinged cover 36 having a screwless cover latching means 52, which is not defeated by the pressure of expanding internal gases, is disclosed. The enclosure 10 includes a rain channel 76 located immediately adjacent a front edge of the box top 28. The rain channel 76 is generally J-shaped in cross-section and extends across the front of the box 14 and slightly beyond the two side walls 18 and 22 of the box 14 such that any liquid being received within the rain channel 76 will be directed over the side walls 18 and 22 of the box 14. The rain channel 76 cooperates with a downwardly extending flange 40 along the front edge of the box top 28 and an inwardly extending flange 60 along the top of the side hinged cover 36 to prevent the ingress of liquid at the top of the cover 36. Inwardly facing flanges 68 and 72 along the sides of the hinged cover 36 overlap the side walls 18 and 22 of the box 14 to prevent the ingress of liquid along each side of the cover 36.

Abstract: An assembly for auotomatically mating a plug terminal attached to the exterior of a circuit breaker with a receptacle terminal attached to the interior of a switchgear cell to provide secondary connections therebetween. The assembly includes a plug having a generally planar body partially defined by a surface and opposing surface. A plug terminal is supported by the opposing surface of the plug. A mounting bracket is slidably affixed to the opposing surface of the plug. The bracket has an aperture to allow the plug terminal to extend therethrough. The bracket is secured in a fixed position to the exterior of the circuit breaker. The position of the plug is automatically adjusted to provide proper alignment between the plug terminal and the receptacle terminal to form an electrical connection between the terminals which can be disengaged.

Abstract: The present invention relates to a transformer comprising a coil having an insulated wire formed into a plurality of turns defining a layer and a resistive element wrapped around the outer surface of the layer. The resistive element couples one of the plurality of turns with another of the plurality of turns. The resistive element not only increases the series capacitance of the transformer, but also increases the series conductance of the transformer circuit. The increase in the series resistance increases the dampening of the switching resonance.

Abstract: The present invention provides a device for electrically connecting electrical conductors of two adjacent sections of a multi-phase electrical distribution system. The connecting device includes a generally cylindrical body enclosing two ground connectors, two outside insulators and two inside insulators intermediate the outside insulators. Each of the outside and inside insulators includes an equal number of semi-circular shaped electrical connectors which are arranged such that each electrical connector on one of the outside insulators has a corresponding electrical connector on one of the inside insulators thus forming a pocket. Each pocket receives one electrical conductor from each of the two adjacent sections of the electrical distribution system.

Abstract: A trip device comprises a removable module for determining long delay tripping parameters, designed to be fixed to a front panel of the trip device. In the fixed position, the removable module exerts a pressure, via an auxiliary part, on a movable part so as to move the latter to a position in which it performs voltage connection of the processing circuit of the trip device to the conductors of a power system to be protected. In an unlocked position of the removable module, the movable part is urged to the disconnected position by a spring. The part can be movable in rotation or in translation.

Abstract: An apparatus for providing precise alignment between primary and secondary contacts mounted on a circuit breaker and associated stationary primary and secondary contacts located with substantial precision with respect to X, Y and Z coordinates and mounted on a back panel of a switchgear breaker compartment. A locking/locate cradle is provided with two generally parallel guide rails that slidably receive and support the circuit breaker within the breaker compartment. The precise X, Y and Z-axes alignment of the guide rails with the X, Y and Z axes position of the stationary primary and secondary contacts on the back panel is crucial for proper mating and connection with the associated breaker primary and secondary contact. The back panel is provided with at least one alignment slot having two indexing sections spaced apart by an aligning section.

Abstract: This invention relates to a cooling system for a transformer. A winding defining a coil, including a duct having an open top and bottom, is sealed to a sleeve, thus forming a closed circulatory path. A fluid is retained and circulated within the circulatory path.

Abstract: An improved low voltage winding for dry insulated transformer has its windings resin encapsulated. The winding is constructed with flexible sheet conductors wound coincident with an insulating sheet material. Insulating spacers provide a means to form air channels in the windings during the coil forming process. A sealant is applied to openings at the lower ends and along vertical seams of the coil prior to the resin impregnation and encapsulation process. This will prevent drainage of the resin during a curing cycle. The result is a coil that exhibits high short circuit protection due to the tightly bond sheet conductors which will prevent movement of the conductors during short circuit conditions and also increases the radial compressive strength of the coil.

Abstract: A motor control circuit controls operation of a motor for making or breaking one or more pairs of contacts of a power switching device such as a circuit breaker. The motor control circuit includes a logic circuit responsive to a control input signal and an enable signal for producing an active signal state when both the control signal and the enable signal are present, and for producing an inactive logic signal state when either of the control signal and the enable signal is not present. A switching control signal producing circuit is responsive to said active state of the logic signal for producing a switching control signal for operating the motor for a predetermined time interval sufficient to perform one of opening and closing of the one or more pairs of contacts.

Abstract: An arcing fault protection system for a switchgear enclosure includes a switching device for rapidly diverting current from the source bus of an electrical distribution system in response to the detection of arcing faults in the system. The switching device, which may comprise a mechanical switch, a solid-state switch or hybrid device, quickly diverts current carried on the source bus to effectively extinguish arcing fault currents present in the distribution system, preventing the generation of gases at high pressures and/or temperatures so as to protect the switchgear equipment from damage.

Abstract: A knockout providing either bundled wiring or multiple electrical conduit connector access to an electrical enclosure. The knockout provides one large knockout for use with bundled wiring or a large conduit connector when activated and a number of small knockouts, each for use with one small conduit connector when activated. The small knockouts are arranged tangentially within the larger knockout in a radial pattern.