Abstract: An efficient configuration for a power system is provided, e.g. for high-speed source transfer, utilizing power electronic assemblies and a directed ventilation arrangement. Each power electronic assembly includes a plurality of stacked power electronic device modules that are electrically series connected and energized at various voltages. Each power electronic device module includes two heat sinks, a power electronic component assembly interposed between the two heat sinks, and an arrangement for clamping the heat sinks and the power electronic component assembly. In a preferred embodiment, the power electronic component assembly includes two stacked, series connected power electronic components such that single-sided cooling is provided. In one application, the power-electronic components are thyristors that have a high short-term, fault-current rating and a relatively low average current requirement.

Abstract: A control arrangement and method is provided for a power electronic system configured as a high-speed source-transfer switching systems (HSSTSS). The HSSTSS supplies an electrical load with alternating current from either a first source or a second source via respective first and second solid-state switches. The HSSTSS also includes a controller that samples the voltage waveforms of each of the first and second sources to detect when transfer between the sources is desirable, e.g. outages or voltage that is either too low or too high. The controller provides appropriate control signals to control operation of the solid-state switches and transfer supply of the load therebetween. The control arrangement avoids undesirable current flow between sources via a comparison of the voltages of the sources and current in the outgoing source, i.e.

Abstract: An operation counter arrangement is provided for a circuit interrupter for opening a high-voltage circuit-isolating device. The operation counter arrangement responds to actual operations via response to a moving contact arrangement of the circuit interrupter. The operation counter arrangement is capable of retrofit to existing circuit interrupters via replacement of an exhaust control device of the circuit interrupter. In a preferred arrangement, a count of both the total number of operations and the number of operations since the most recent maintenance is provided.

Abstract: An arrangement provides a power supply for low voltage circuits that is connected to receive and store energy from a power electronics switch that is connected to an alternating current supply. The power supply is operative over a wide range of input and regardless of the operating status of the power electronics switch. For each half cycle of the alternating current which the power electronic switch is to be rendered conductive, the arrangement delays for a predetermined time duration the control of the power electronic switch at the zero crossing of the half cycle. During the predetermined time duration, the power supply charges an energy storage device with sufficient energy to supply the low voltage circuit until the next half cycle.

Abstract: A fault interrupter is provided that includes a high-speed disconnect in series with an interrupter wherein the circuit opening is via the interrupter and the circuit making is via the disconnect. A stored energy disconnect operating mechanism operates the disconnect between ground, open and closed positions and also charges the interrupter mechanism during a slow opening of the disconnect without fully charging the disconnect operating mechanism. Thus, the required operating forces to open the disconnect and charge the interrupter mechanism are reduced. During a manual opening, the disconnect operating mechanism trips open the interrupter, then only partially charges to begin opening the disconnect before releasing the stored energy. Continued operation of the disconnect operating mechanism slowly drives the disconnect open while charging the interrupter mechanism and closing the interrupter.

Abstract: A voltage sensing arrangement is provided that facilitates accurately measuring a sensed voltage while also providing isolation to a sensing path during a test mode of an associated indicator arrangement. The voltage sensing arrangement includes a voltage sensor that is arranged to sense the voltage on an associated power distribution line. A first arrangement is responsive to the voltage sensor for providing an output representing the voltage on the associated power distribution line. The voltage sensing arrangement includes a second arrangement that is responsive to the voltage sensor for isolating the first arrangement from the voltage sensor whenever voltage is not present on the associated power distribution line. In a preferred embodiment, a third arrangement is provided that is responsive to the presence of voltage on the associated power distribution line for isolating a test path from the voltage sensor.

Abstract: A control arrangement and method is provided for source-transfer switching systems including a high-speed control arrangement and high-speed switches to control the transfer of a load from one source to another with minimal transfer delays. The system supplies an electrical load with alternating current from either a first source or a second source via respective first and second switches. The system also includes a controller that samples the voltage waveforms of each of the first and second sources to detect when transfer between the sources is desirable, e.g. power outages, voltage levels that are either too low or too high, or reverse currents that indicate an upstream fault. The controller provides appropriate control signals to control operation of the switches and transfer supply of the load therebetween.

Abstract: A disconnect feature is provided for a circuit interrupter that is conveniently incorporated with the circuit interrupter. The disconnect feature is operable between closed and open positions, providing a visible open gap in the open position. The disconnect feature includes a pivotally mounted contact arrangement that is supported with respect to the circuit interrupter. The pivotally mounted contact arrangement cooperates with an interengaging contact carried by a contact terminal of the circuit interrupter. In specific arrangements, interlock features are provided to disable operation of the circuit interrupter when the disconnect feature is moved out of the closed position. In one arrangement, the disconnect feature is blocked from operation until the circuit interrupter is operated to an open circuit position.

Abstract: Switchgear is provided that includes a housing enclosing electrical components having switch blades that establish visible open gaps in an open position. The switchgear includes an array of operating controls and viewing provisions to observe the open switch blades. The operating controls and viewing provisions are accessible from a first direction and are arranged at a first area of the housing while cable interconnection provisions are accessible from a second direction and are arranged at a second area of the housing. Thus, operating personnel can utilize the viewing provisions and the operating controls without being exposed to the area of the cable interconnections. In one specific arrangement, an array of operational displays is provided, with the displays overlying the viewing provisions and being movable to permit use of the viewing provisions. In a preferred arrangement, the switchgear includes multi-pole switchgear assemblies which are assembled from individual pole-unit assemblies.

Abstract: Switchgear is provided that includes a housing enclosing electrical components having switch blades that establish visible open gaps in an open position. The switchgear includes an array of operating controls and viewing provisions to observe the open switch blades. The operating controls and viewing provisions are accessible from a first direction and are arranged at a first area of the housing while cable interconnection provisions are accessible from a second direction and are arranged at a second area of the housing. Thus, operating personnel can utilize the viewing provisions and the operating controls without being exposed to the area of the cable interconnections. In one specific arrangement, an array of operational displays is provided, with the displays overlying the viewing provisions and being movable to permit use of the viewing provisions. In a preferred arrangement, the switchgear includes multi-pole switchgear assemblies which are assembled from individual pole-unit assemblies.

Abstract: Coupling apparatus is provided for assembly with separable insulated connector components on power cables for power distribution systems. The coupling apparatus provides either direct or indirect coupling, e.g. to provide interconnection to the connector components or to provide a sensing point. In one illustrative embodiment, the coupling apparatus is installed in place of a conventional double-ended plug that is required to piggyback T-body elbows, i.e. where multiple elbows are to be connected. In one specific arrangement, the coupling apparatus includes a desired connector interface. In another specific arrangement, a sensed voltage output is provided using components such as capacitive coupling components, capacitors, resistors or transformers. In another embodiment, the coupling apparatus is used in place of a conventional insulating plug that is used to attach a T-body elbow to a bushing, e.g. on switchgear assemblies or the like.

Abstract: A power operator for switchgear and the like is provided that is capable of either power or manual operation without the necessity of any decoupling or mode selection. The power operator is compact and easily affixed over a manual operating shaft of switchgear. The manual drive capabilities are always coupled for operation without any backdriving of the power source. The power operator includes a drive output affixed to the switchgear operating shaft, a manual operating shaft, and an arrangement for selectively coupling a power-driven input to the switchgear operating shaft. In a specific arrangement, the control arrangement of the power operator senses the position of the drive output and also senses the current drawn by the drive source. When controlling switchgear having a stored energy mechanism, operating positions are detected by sensing the tripping of the stored energy mechanism via the sensed current through the drive source.

Abstract: A phasing and indicator arrangement is provided for switchgear or the like that responds to electrical sources and provides voltage indicator functions, phasing determinations, and self-test features. Phasing provisions are responsive to two or more voltage sensors proximate respective electrical sources to provide an output that represents the phase difference, i.e. time relationship, between the electrical sources as an alternatingcurrent voltage measurable by a voltmeter. The output is relatively independent of the voltage of the electrical sources. The indicator arrangement is operable in a test mode to test the integrity of one or more voltage indicators while clearly identifying that the indicator arrangement is in a test mode. In a preferred arrangement, the indicator arrangement in the self-test mode is powered by a photocell.

Abstract: A separable, flexible connection arrangement (10) is provided for connection of two conductors (12, 14). In one arrangement, the separable, flexible connection arrangement (10) is utilized to provide an externally removable bushing (16) for connecting an electrical component located within a sealed enclosure (19). The flexible connection arrangement (10) includes two joints (20, 22) formed by two link members (50a, 50b) that are spring-biased and include protuberances (40, 42) that interfit into slots (30, 32) of the conductors (12, 14). A spacer (72) may be used to maintain spacing of the protuberances (40, 42) and also acts as a stop when contacted by the ends of the slots (30, 32). One of the slots (32) is formed with an open end (74) to enable easy insertion between the link members (50a, 50b). Alternatively, one of the conductors (100) includes a set of grooves (102, 104).

Abstract: Switchgear is provided including an enclosure for pad-mounted installation. The enclosure includes large lift-up cover panels in combination with removable front panels so as to provide unobstructed access to the interior of the enclosure. In a preferred arrangement, the enclosure houses switchgear that includes low-voltage control and viewing arrangements that are operable from a first side of the switchgear and medium-voltage cable terminations that are accessible from a second side of the switchgear opposite the first side, the enclosure providing access to the low-voltage arrangements while providing isolation from the medium-voltage arrangements. The enclosure also includes protection from the environment in the area of the lift-up cover panels while also providing collapsible lifting members.

Abstract: A power operator for switchgear and the like is provided that is capable of either power or manual operation without the necessity of any decoupling or mode selection. The power operator is compact and easily affixed over a manual operating shaft of switchgear. The manual drive capabilities are always coupled for operation without any backdriving of the power source. The power operator includes a drive output affixed to the switchgear operating shaft, a manual operating shaft, and an arrangement for selectively coupling a power-driven input to the switchgear operating shaft. In a specific arrangement, the control arrangement of the power operator senses the position of the drive output and also senses the current drawn by the drive source. When controlling switchgear having a stored energy mechanism, operating positions are detected by sensing the tripping of the stored energy mechanism via the sensed current through the drive source.

Abstract: Switchgear is provided that includes a housing enclosing electrical components having switch blades that establish visible open gaps in an open position. The switchgear includes an array of operating controls and viewing provisions to observe the open switch blades. The operating controls and viewing provisions are accessible from a first direction and are arranged at a first area of the housing while cable interconnection provisions are accessible from a second direction and are arranged at a second area of the housing. Thus, operating personnel can utilize the viewing provisions and the operating controls without being exposed to the area of the cable interconnections. In one specific arrangement, an array of operational displays is provided, with the displays overlying the viewing provisions and being movable to permit use of the viewing provisions. In a preferred arrangement, the switchgear includes multi-pole switchgear assemblies which are assembled from individual pole-unit assemblies.