Abstract: A recloser trips on one phase for single-phase only fault conditions, two phases for two-phase fault conditions, or all three phases for three-phase fault conditions. During power delivery, the recloser monitors the three phases of a power line (e.g., phases A, B, and C). If a fault is detected on one phase, then a timer is started and subsequently decremented. If the timer finishes counting down while the fault is still present, then it is determined if any of the other two phases are timing a fault. If so, then those phases having a fault are tripped. Thus, only the faulted phase(s) is (are) tripped.

Abstract: A recloser is adaptively controlled so that it will operate in a manner responsive to prevailing conditions such as time of day, day of week, and/or load current. A protection setting group is stored in a memory accessible by the recloser controller, and contains a set of instructions for controlling the recloser based on the prevailing conditions. The prevailing conditions are continuously monitored, and the control of the recloser is based on the prevailing conditions and the protection setting group.

Abstract: A circuit breaker lockout device is provided that prevents the breaker contacts from being closed when the circuit breaker is in a lockout state in response to a lockout signal and permits the breaker contacts to be closed when the circuit breaker is an enable state in response to an enable signal.

Abstract: Transformers (14) inject test voltage signals of know frequency to each phase of the load side of an electrical distribution circuit (15). Processor (32) waits for a delay period to allow transient effects of the injected signals to settle, and then accepts the sampled test current signals provided by current transformers (12) through conditioning circuit (16). This process is repeated by injecting test voltages at different frequencies, which are selected by processor (32) based on stored instructions. Processor (32) uses the sampled signals to determine a representative current for the load side of the distribution circuit (15) and then compares the representative current with a predetermined current threshold value stored in non-volatile memory (40). If the current is above this threshold, processor (32) provides a lockout signal to the fault lockout device (48) and fault lockout flag (50).

Abstract: An improved circuit supplies electrical power to a vehicle accessory load, such as a load that is powered through a vehicle accessory load connector or cigarette lighter plug. The circuit utilizes battery voltage comparator and timer switching circuitry to interrupt the supply of power to the accessory load if the engine-driven alternator fails to charge the storage battery for at least a predefined time interval (i.e., when the vehicle engine is not running), and to automatically re-establish electrical power supply to the load when battery charging resumes (i.e., when engine operation resumes).

Abstract: An improved electrical lockout mechanism includes a first connection means to a power source, and a second connection means to the power input terminal of the machine being protected. The machine being protected includes a manually-operated ON/OFF switch. A switching element is operably coupled between the first and second connection means. The switching element is adapted to selectively complete and break an electrical circuit between the first and second connection means in response to a control signal supplied thereto. A control circuit generates a control signal that is supplied to the switching element thereby causing the switching element to complete the electrical circuit between the first and second connection means under a first set of operating conditions and causing the switching element to break the electrical circuit between the first and second connection means under a second set of operating conditions in a manner that prevents unwanted machine restarts.

Abstract: A circuit board includes two or more electric members attached onto the board, and two or more peripheral frames attached onto the board and disposed around the electric member respectively, for separating electric member from each other and for preventing the electric member from being interfered with each other. The peripheral frame are preferably conductive and/or preferably grounded for facilitating the frequencies separating between the electric members. The board includes two or more peripheral lines, and the peripheral frames are engaged onto the peripheral line.

Abstract: To shorten the recovery time of a line driver (1) after an overvoltage on its output terminal (3), a current generating device (5) senses a voltage difference between the output voltage of the line driver (1) and its supply voltage (UB) plus a threshold voltage (UT′), and supplies a current (I) that is proportional to the sensed voltage difference up to a maximum current to the output (3) of the line driver (1) to raise its potential to thereby shorten its recovery time.

Abstract: Resettable circuit interrupting devices, such as GFCI devices, that include reset lockout portion that does not test the circuit interrupter are provided.

Abstract: A battery pack for a DIMM memory module is disclosed. The battery pack comprises a first casing part and a second casing part. The second casing part may be joined to the first casing part to encase at least one battery. The second casing part includes a lip capable of engaging one side of a printed circuit board and a flexible tab terminating in a hook, the hook being capable of securing the battery pack to the printed circuit board.

Abstract: A method for handling the voltage drop, at least in the control unit of a robot with a PC control is provided that minimizes the time of a plant stoppage and avoids wasteful process interruptions. The PC control has a real time operating system for the time critical control and regulation of the robot movement and a standard PC operating system for communication with an operator. In the case of a voltage drop a battery/accumulator operation takes place with running robot movement and optionally application operations broken off or ended in a clearly defined manner. Then, working processes of the control are terminated. The contents of the working memory at the termination time concerning the real time operating system and robot control programs are stored, particularly as an image, in at least one mass memory. For restarting the robot after such a stoppage thereof the standard PC operating system is loaded in the conventional manner into the working memory and started.

Abstract: This invention provides a residual current detector comprising a trip circuit; a magnetic lock assembly including a solenoid that operates in response to a signal from the trip circuit, causing movement of an operating member, with the magnetic lock further including a reset mechanism for resetting the residual current detector following a trip operation; and means for preventing reset of the magnetic lock by restraining movement of the solenoid when the trip circuit is disabled. In the preferred embodiment, a plunger assembly is mounted adjacent to the solenoid of the magnetic lock assembly and fusible link is connected in series with the trip circuit and mounted to prevent movement of a plunger in the plunger assembly. When the trip circuit is subjected to excessive current, the fusible link will melt, thereby permitting the plunger to interfere with movement of the armature of the solenoid. This prevents rest of the magnetic lock assembly.

Abstract: A feeder restoration method starts in response to an overcurrent fault on a feeder (22) that causes a circuit breaker (42) to trip open, reclose once, trip again, and attempt to reclose again. During the time period between the first and second reclosings, any remote sectionalizing switches (46) on the faulty feeder are opened if they have also sensed the overcurrent fault, and a substation processor (50) evaluates the status of the faulty feeder and an alternate feeder (32, 34). After the second trip of the circuit breaker, the processor verifies whether the remote sectionalizing switch was closed and a remote tie switch (40) to the alternate feeder was open. If the circuit breaker locks open, the substation processor determines whether the remote sectionalizing switch did not sense the overcurrent condition (which indicates that the fault is between the circuit breaker and the sectionalizing switch) or simply failed to open.

Abstract: An installation for power transmission by high-voltage direct current has at least two converter stations which are interconnected by a dc line (DC), at least one station (SR1) having a line protection device (LP) adapted to detect a ground fault on the dc line and, when a ground fault is detected, to achieve a reduction of the voltage (U.sub.D) and the current (I.sub.D) of the line and thereafter to make a restart attempt. The installation has, in addition, a detection circuit (FD) for detection of a permanent low-impedance ground fault on the dc line. The detection circuit is activated after an intervention by the line protection device. During a detection interval, the detection circuit causes one of the stations (SR1) to feed a current into the line.

Abstract: A circuit breaker includes separable contacts for movement between a closed position and an open position, and an operating mechanism for moving the separable contacts between the closed and open positions. Current transformers and potential transformers sense current, voltage and frequency conditions of the separable contacts and produce signals corresponding to those electrical conditions. A trip unit employs those signals corresponding to the electrical conditions to produce a trip signal. A trip coil employs the trip signal to actuate the operating mechanism to move the separable contacts to the open position. A closing mechanism produces a close signal, and a close actuator mechanism employs the close signal to actuate the operating mechanism to move the separable contacts to the closed position. The trip unit includes a microprocessor-based firmware routine for selectively enabling and disabling the close actuator mechanism as a function of the signals corresponding to the electrical conditions.

Abstract: An improved auto-reclosing dead time control apparatus and a method thereof for a transmission cable protection relay system which is capable of providing an on-line stability evaluation method which is capable of controlling the dead time of the transmission cable automatic reclosing relay in accordance with the stability margin, which includes an electrical system for controlling an automatic reclosing operation in accordance with a variation of a transmission cable failure dead time, a transient stability margin evaluation means for evaluating a transient stability margin in accordance with a failure information inputted from the electrical system, and a reclosing relay means for varying the dead time in accordance with a transient stability margin evaluated by the transient stability margin evaluation means.

Abstract: An electrical contact position indicator assembly is operatively coupled to an electrical device, such as a recloser, for indicating the relative position of the contacts of the electrical device, i.e., opened or closed, at any given time during operation of the electrical device. The position indicator assembly includes a movable indicator having first indicia to indicate that the contacts are opened, and second indicia to indicate that the contacts are closed. Each of the first and second indicia of the indicator lies in more than one plane. Preferably, each of the first and second indicia of the indicator lies on a three-dimensional, curvilinear or spherical surface. In the preferred embodiment, the indicator includes a mechanical linkage to the contact opening and closing assembly.

Abstract: A combined bell alarm and lock-out accessory is connected with the electronic trip unit that controls a high ampere rated circuit breaker. The accessory interacts with the circuit breaker operating mechanism to activate the bell alarm upon circuit interruption and to prevent the closing of the circuit breaker contacts until the accessory is manually reset. The circuit breaker lock-out mechanism interfaces between the circuit breaker operating mechanism and the accessory to insure that the contacts remain open until the accessory is completely reset.

Abstract: In communication systems, a dc voltage source can be connected via a first and a second winding of an input transformer and a subscriber line to every communication terminal equipment device by using an electronic switch. In case of an overload, the turn-off duration, i.e. the time until the disconnect of the dc voltage source is influenced dependent on a load-generated loop current by using an integrating element and a comparator. As a result thereof, short turn-off durations and, consequently, significantly reduced thermal loads on the electronic switch occur given substantial overloads. The present invention allows the use of electronic switches having a lower maximum load.

Abstract: An auto-recloser circuit-breaker has three vacuum interrupters driven from a single bistable magnetic actuator which is powered by a first lithium sulphur dioxide battery under control of an electronic protection relay which is powered by a second lithium sulphur dioxide battery. The drive mechanism, actuator and relay are designed to minimize current consumed by the batteries so that the recloser may be self-powered for its full life by these batteries independent of the power line in which it is connected.

Abstract: An overcurrent protection circuit is provided with a counter which permits a preselected number of reinitiations of current following the detection of an overcurrent condition. Each stoppage of current in response to the detection of an overcurrent condition is followed by a predetermined time delay and a subsequent reinitiation of current. After the predetermined number of reinitiations, current is permanently stopped from flowing between first and second circuit points until a manual reset occurs.

Abstract: Object of the present invention is to provide a controller for distribution apparatus which prevents extension of power failure.In accordance with the controller for distribution apparatus related to the present invention, when a short circuit accident, for example, occurs in a control circuit for distribution apparatus, a breaker for distribution opens, an auxiliary coil becomes unexcited condition, and power failure is caused, but, an auxiliary contact point of the unexcited auxiliary coil closes in the other control circuit for distribution apparatus so as to excite a closing coil, and consequently, the other control circuit starts its operation immediately. Accordingly, extension of the power failure can be prevented and reliability of power supply can certainly be maintained.

Abstract: A battery drain limitation circuit, for use in engine-powered vehicles and equipment that rely on a battery for starting the engine and for operating accessories, disconnects the battery from all loads when the battery voltage falls to a level below which the battery charge may be insufficient to start the engine. The circuit is rendered inoperable, when the engine is running, by means of a microphone that detects engine noise. The circuit includes a reset mechanism that reconnects the battery to all loads. The reset mechanism may be automatic or manually actuated. A timing circuit delays the disconnection for a period of time sufficient to start the engine. The drain limitation circuit employs a latching relay that, in its preferred embodiment, includes front and rear coils in tandem, axially separated by a collar with an internal detent. A front plunger and a rear plunger are disposed for axial movement within the coils and the collar.

Abstract: The electronic trip device comprises a device for selecting the faults which are to bring about locking of the circuit breaker contacts in the open position. When a fault in the power supply system protected by the circuit breaker leads to a trip, the trip device orders locking if this fault is one of the faults selected by the selection device.

Abstract: An electronically controlled recloser for an electrical power distribution system is powered by at least one current transformer coupled to give an output in response to power line current. A voltage is stored on a large and a small capacitor in response to the line current and is compared with a reference voltage for determining the level of line current. When abnormally high levels of current appear on the line, it is opened for a short period of time. The energy stored on the capacitors is supplied to power the recloser during low line current conditions. At an end of a given time period following the opening of said line, the recloser recloses the line. If the abnormal condition persists, the recloser again opens and closes the line. When there is a surge of line current, the large capacitor is effectively removed from the circuit so that a response will not be delayed while the large capacitor charges; therefore, the charge on the small capacitor provide a quick start for immediate response.

Abstract: A recloser apparatus is provided with an enclosure or tank (40) in which a current interrupter assembly (49) is disposed that includes a pair of relatively movable contacts (50, 54) movable between a closed, current-carrying position and an open, current-interrupting position. An opening assembly (60) is included for opening the contacts to the current-interrupting position and a closing assembly (66), including a high voltage solenoid coil (61) and plunger (116) moves one of the contacts (54) to the closed, current-carrying position. An operating assembly (43) is manually accessible from outside the tank (40) and includes an operating arm (44) which is movable between an upper, intermediate and lower position, and a contact closing circuit for initiating operation of the contact closing assembly (66) when the operating arm (44) is manually moved to the upper position.

Abstract: An electrical recloser apparatus includes a tank (10) having bottom, top and side walls (18, 22, 16) which define an interior, sealed space (14), and a current interrupter (44) disposed within the sealed space (14) and including a pair of relatively movable contacts (46, 48) which are movable between a closed, current-carrying position and an open, current-interrupting position. A control assembly (30) is provided for electronically controlling the opening and closing of the contacts (46, 48), the control assembly (30) initiating operation of the contact moving means (58) to move the contacts (46, 48) to the open position in response to a fault current sensed by a sensing means (66), and initiating operation of the contact moving means (58) to move the contacts (46, 48) to the closed position after each one of a predetermined number of opening operations.

Abstract: Apparatus for improving the performance of conventional electromagnetic reclosing relays under continuous lower magnitude ground or phase faults in electrical power distribution systems. An incomplete sequence relay is connected to the reclosing relay to render the timing drum or cam of the reclosing relay operative when the contacts of the circuit breaker are open, and to reset the reclosing relay after a selected time interval when the breaker is closed. This arrangement prevents timing problems associated with lower magnitude faults which otherwise keep the reclosing relay from reaching its lockout condition.

Abstract: An auto-recloser for a power line has a high voltage closing coil (12) for closing the main contact (14) in the power line, the closing coil being energized via a non-latching switching (18) in turn controlled by a low voltage closing coil (20). A time closing pulse is applied to the low voltage coil (20) to close switch (18) for a very short time period. A coil protection (24) monitors the status of the main contants (14) and if these have not closed after a preselected time period of typically 100 ms then the protection circuit opens a normally closed switch in series with the low voltage coil (20) to prevent further closing pulses being applied in further attempts to close the main contacts (14).

Abstract: A hybrid analog and electronic cycle timer has a mechanical movement and cam-operated cycle switch driven by a low-RPM synchronous motor. Electronic control logic divides the power line frequency to obtain pulses for pulsing the synchronous motor. The control logic also includes an activation interval timer and a lockout flip-flop which inhibits the activation interval timer. The activation interval timer is otherwise triggered by closure of the cycle switch. The lockout flip-flop is set after a power failure and at the end of the activation interval, and is reset by a manual reset signal. The activation interval timer may include an activation enable flip-flop and an activation interval counter. The state of the control circuit is conveniently indicated by an indicator which is activated continuously during the activation interval, and which is activated intermittently when the activation interval timer is inhibited by the lockout flip-flop.

Abstract: In a high voltage circuit interrupter (30) or recloser, an auxiliary undervoltage lockout mechanism (300) provides a backup lockout means to deenergize circuit contactor closing solenoid (78). Auxiliary undervoltage lockout device (300) provides a backup means to lock out recloser (30) after a period of time longer than the normal functioning time of the recloser to prevent damage to closing solenoid (78) in the event of low voltage or other unexpected conditions on the power line.

Abstract: A trouble detection apparatus for an air conditioner detects overcurrents occurring within a predetermined time period t.sub.2 which is a shortest time period necessary for stabilization of the compressor operation. By counting a number of occurrences of the above-mentioned detections as criteria of actual trouble, the compressor is stopped when the number becomes two or more; thereby unnecessary interruption of operation of the air-conditioner due to electric noise or a simple overload is eliminated.

Abstract: The traction motors of a locomotive are voltage limited to a variable extent to permit continued motor operation following the occurrence of moisture induced ground faulting. The heat generated by the continued motor operation dries the moisture which induced the ground faulting, and the voltage limit is progressively increased toward a normal level for each specified period of motor operation with no ground faulting.

Abstract: A reclosing relay for reclosing a circuit breaker in an electrical power system. The reclosing relay is a multi-shot reclosing relay (i.e., providing more than one reclosure command to the circuit breaker) and includes primary and redundant lockout circuits for each reclose circuit. The primary lockout scheme employs a flip-flop, with a reset timer for resetting if the breaker remains closed after the first reclosure. The flip-flop is set when the circuit breaker recloses to lockout the first reclosure circuit. The redundant lockout circuit locks out the first reclosure circuit after a trip, reclose, and retrip sequence. The second reclose circuit includes similar primary and redundant lockout circuits.

Abstract: A distribution line powered switchgear control is provided which reliably initiates switchgear operations with stored energy. Stored energy is preferably maintained in a plurality of devices including a power capacitor. The power capacitor is preferably charged by a fast arming circuit which preferably selects among a plurality of independent power sources. The switchgear control additionally isolates sources of stored energy so that depletion of one does not affect the others. Further the switchgear control will preferably prevent closing of the switchgear unless sufficient energy is stored to allow the control to initiate a subsequent opening of the switchgear.

Abstract: A relay spare circuit for a recloser relay provides an output signal selected to occur during a particular segment of the reclose cycle of a fault-responsive circuit breaker. A set of switches is provided to select which of a plurality of available recloses are to be used and where in the resulting reclose cycle the relay spare is to operate, and a logic circuit is provided which compares the selected switches with a counter responsive to advancement of the recloser relay through the reclose cycle, to provide the relay spare output signal at the selected point in the reclose cycle.

Abstract: A remotely controlled circuit control device has first and second load contact assemblies movable into circuit engagement and circuit disengagement positions relative to one another in which one load contact assembly is operatively connected to a solenoid so that alternate forward strokes of the solenoid moves the one load contact assembly between reset and tripped positions through a push-push mechanism having an indexing portion and a latching portion. An overload mechanism cooperates with the latch portion to cause the load contact assemblies to move to the circuit disengaged position upon occurrence of a fault condition. The second load contact assembly includes pivotably mounted contact members which are linked to the first load contact assembly in such a way that circuit engagement during solenoid energization is precluded.

Abstract: A reset lockout addition to an A.C. overload current sensing, remote power controller of minimum size and weight and integral construction. Current rate sensing wound toroids are used that are small enough to fit around the line terminal studs without having to enlarge prior insulator space available therein. The electronic overload current detecting and tripping control circuit, is replaced by a pair of modules, detector and control modules, having improved performance and a shape and size such that they fit within the relay housing alongside its operating magnet. The detector module has integrator means for converting current rate of change signals into magnitude indicative signals thereby enabling use therewith of rate sensing wound toroids of about one-tenth the size of equivalent current transformer wound toroids.

Abstract: A protective system interposed between a d-c power supply and an external load to isolate the supply from the load should the current drawn therefrom exceed a predetermined threshold value, the system distinguishing between a transitory overload and a continuous overload condition. The system includes a current-sensing resistor connected in series with the supply and the load and a comparator responsive to the voltage drop developed across the resistor to produce an output signal which activates a relay to cut off the delivery of current to the load only when the current exceeds the threshold value. Also included is a sampling circuit which upon activation of the relay functions after a brief sampling interval to automatically de-activate the relay and thereby reconnect the supply to the load, causing the comparator to again determine whether the existing current drain is still excessive, in which event the relay is again activated and the sampling cycle repeated.

Abstract: The circuit breaker is taught with an anti-pumping control circuit. If the circuit breaker closes on a fault and quickly reopens without the closing switch being either mechanically or electrically released in the interim, reclosure of the circuit breaker either by an automatic reclosure or by the mere fact that the closing switch remains closed will be prevented until the closing switch is once again opened. In addition, if the closing switch is actuated prior to power being applied to the circuit breaker control system, the circuit breaker will not close when power is applied. The closing spring will be charged, however, for a subsequent circuit breaker closing after release and reactuation of the closing switch.

Abstract: An automatic recycle circuit is disclosed for use in a process or apparatus of the type wherein process or equipment conditions are monitored to detect an abnormal condition. The automatic recycle circuit accepts inputs from monitor circuits which are intended to cause recycle operation and monitor circuits which are intended to cause complete shutdown and reacts appropriately to each type of input. With respect to those inputs from monitor circuits which are intended to cause recycle action, the automatic recycle circuit is capable of permanently shutting down the process or apparatus if the detected abnormal condition has a duration exceeding a first predetermined time or abnormal conditions are detected a predetermined number of times within a second predetermined time period.

Abstract: An improved ground fault tester uses a magnetostrictive element or piezo-electric element, such as a multimorph, which changes dimensions upon being magnetized or electrically charged. The dimensional change is used to interrupt the power circuit in which the ground fault occurs. The existence of a ground fault is sensed by a sensor which supplies current to the magnetostrictive or piezo-electric element. In the case of the piezo-electric element, the charge is dissipated through a parallel discharge circuit whereby interruption of the power circuit is accomplished rapidly and is reclosed only after a time delay. Automatic time delay resetting may be easily accomplished by the addition of a single resistor and a rectifier.