Abstract: A control system includes an Internet web interface to a network of at least one programmable logic control system running an application program for controlling output devices in response to status of input devices. The Web interface runs Web pages from an Ethernet board coupled directly to the PLC back plane and includes an HTTP protocol interpreter, a PLC back plane driver, a TCP/IP stack, and an Ethernet board kernel. The Web interface provides access to the PLC back plane by a user at a remote location through the Internet. The interface translates the industry standard Ethernet, TCP/IP and HTTP protocols used on the Internet into data recognizable to the PLC. Using this interface, the user can retrieve all pertinent data regarding the operation of the programmable logic controller system.

Abstract: Automatically configurable master and slave devices in a master/slave multi-drop serial network are disclosed. In one embodiment, the devices and network utilize the Modbus serial communications protocol over a serial multi-drop network, such as an RS-232 or RS-485 (also referred to as EIA-485) based network. Alternatively, the disclosed embodiments may be used with any master/slave serial multi-drop network. In one embodiment, the master and slave devices include pseudo-slave and pseudo-master auto-configuration operating modes, respectively, whereby slave devices which are introduced to the network may send unsolicited identifying messages to the master device which will determine and assign a unique network address thereto, causing the slave device to configure itself to be responsive to messages addressed therewith and then enter its normal slave operating mode to await such messages. The master device, thereafter, maintains a database of the slave devices and their associated network addresses.

Abstract: A method of automatically detecting an anomalous condition relative to a nominal operating condition in a vapor compression system. An expected input power function in the form of a hyperplane is calculated based on three temperature readings: an intake temperature from an intake area of the condenser unit, a return temperature from an intake area of an evaporator unit, and a supply temperature from a supply output area of the evaporator unit. The function produces an estimate of the expected input power consumed by the compressor unit, and this expected input power is compared with an actual input power measured from the compressor unit. If the expected input power deviates from the measured input power by more than a predetermined tolerance, an indication is stored and communicated that an anomalous condition, such as a refrigerant loss, condenser unit fouling, or a malfunctioning fan, exists in the vapor compression system.

Abstract: A lighting system controller is provided that is configured to automatically discover lighting controllers. In a particular example, the lighting system controller is configured to scan a network for lighting controllers that match a set of search criteria. According to this example, the lighting system controller is configured to present any such discovered lighting controllers to a user in a user interface. In this example, the user interface includes elements configured to allow a user to designate one or more of the discovered lighting controllers for centralized management.

Abstract: A joint pack includes one or more phase members that utilize integrated standoff spacers that protrude and come into contact with opposing conductor plates to maintain a phase space between the phase members. The spacers are located along the insulating plates of the phase members away from the phase member's axial sleeves and protrude through apertures in the conductor plates disposed on the phase members, in which the standoff spacers also provide a barrier that prevents phase-conductors from being inserted too far within the phase space. The phase members include axial sleeves that fit within one another during assembly to form a nesting arrangement, thereby reducing the overall size of the joint pack while satisfying standards. The axial sleeves can be distinctively designed such that the phase members must be assembled in a predetermined order, with no components being omitted, to form the joint pack.

Abstract: A lighting system controller is provided that is configured to automatically synchronize a lighting controller with a centralized configuration. In a particular example, this automatic synchronization activity may include modifying the configuration of the lighting controller to match configuration information stored locally on the lighting system controller. Conversely, this automatic synchronization activity may include modifying the locally stored configuration information to match the current configuration of the lighting controller. In some examples, the lighting system controller is configured to use cyclic redundancy checks when determining whether to modify configuration information.

Abstract: A bus assembly and bus assembly connector include one or more insulated members that have axial sleeves that fit within one another during assembly to form a nesting arrangement. The nesting arrangement of the axial sleeves allow reduction of the overall size of the bus assembly connector while satisfying power rating standards and dielectric clearances as well as allowing bolting of the bus assembly to thereby clamp and secure the bus assembly. The axial sleeves can be distinctively designed such that the phase members must be assembled in a predetermined order, with no components being omitted, to form the bus assembly connector or clamp the bus assembly.

Abstract: A shunt for measuring current passing through a conductor. The shunt includes a first section and a second section connected in series with the conductor, and a coaxial cable connected between the first and second sections. An outer conductor of the first section surrounds an internal conductor having a resistance lower than that of the outer conductor of the first section. An outer conductor of the second section surrounds an internal conductor having a resistance higher than that of the internal conductor of the second section. The dimensions of the first and second sections are the same. An internal conductor of the cable is connected between the two sections, and an outer conductor of the cable is connected to the outer conductors of the two sections. The voltage across the outer and inner conductors of the cable is proportional to the current passing through the conductor.

Abstract: A transformer assembly for mounting a current transformer to an electrical apparatus. The generally toroidal current transformer senses electrical current in conductors of the electrical apparatus and has a housing. A mechanical lug for conductors of the electrical apparatus is mounted directly to the housing of the current transformer, within the central opening of the toroid. The mechanical lug has one or more conductor bores located within a main body of the mechanical lug for receiving respective conductor wires.

Abstract: A multi-pole circuit breaker comprising a single main housing containing multiple circuit breakers for protecting multiple branch circuits. Each of the circuit breakers comprises a single line terminal for receiving electrical current from a utility line, a plurality of load terminals for supplying electrical current from the single line terminal to a plurality of branch circuits via load lines, and a plurality of neutral terminals for receiving electrical current returned from the branch circuits via neutral lines Line conductors inside the main housing connect the line terminal to the plurality of load terminals. Sensors inside the main housing generate signals representing characteristics of the electrical current flow in the branch circuits, and a signal processor uses the signals generated by the sensors for detecting abnormal conditions in the branch circuits and generating trip signals in response to the detection of an abnormal condition.

Abstract: A current sensor assembly used for detecting ground faults, which includes an enclosure surrounding the current sensor for focusing the magnetic flux produced by conductors passing through the current sensor assembly away from the conductors, thereby reducing load-shift error and producing more accurate current readings for ground-fault sensing. The enclosure has two half members that are secured together to form a toroid-shaped shell that surrounds a toroidal core of the current sensor. A secondary winding and an optional test winding is wound around the toroidal core, and the ends of these windings exit one or more apertures formed in the enclosure. The half members have rounded profiles where the flat surfaces transition into different planes so that the magnetic flux does not encounter any sharp edges or transitions inside the enclosure as the flux flows away from the conductors.

Abstract: A debris collection slot or groove formed near the exit of a vent channel in a circuit breaker. Debris is produced during a circuit interruption, causing the debris to travel into the vent channel toward an opening where it exits the circuit breaker. Too much accumulated debris can lead to a ground strike or a cross-phase condition. The debris collection groove, formed near the exit opening of the vent channel, has no significant effect on the internal pressure generated during the circuit interruption. Multiple grooves can be formed near the exit opening for trapping more debris. When the vent channel is bent, the grooves are positioned on the outer curve of the last bend of the vent channel to trap the higher-density debris traveling around the curve.

Abstract: A plug-in outlet for a busway system has a base mounted to a busway housing, wherein the base has an opening into which an electrical stab extends from a busbar of the busway system. A fingerguard is mounted to the base into the opening and has self-aligning features achieved by built-in tolerances. The fingerguard includes a central barrier for shielding a leading end of the electrical stab, the central barrier extending from side walls of the fingerguard and being separated by respective gaps from a top wall and a bottom wall of the fingerguard. The fingerguard further includes a top back latch and a bottom back latch for attaching the fingerguard to the stab, the top back latch and the bottom back latch extending from respective ones of the top wall and the bottom wall toward the stab and retaining the stab toward the fingerguard.

Abstract: A low voltage DC power supply is provided in a load center for distributing electrical power from electrical power utility lines to multiple branch circuits via a load center bus connected to the utility lines, each of the branch circuits having a circuit breaker coupled to a processor that is shared by multiple circuit breakers in the load center. The low voltage DC power supply includes a switch mode low voltage power supply connected to the processor for supplying the processor with a DC power input, and a line-derived power supply and a fault-derived power supply coupled between the utility and the switch mode power supply for supplying DC inputs to the switch mode power supply.

Abstract: Methods for improving the accuracy of characterizing unmonitored paths or virtual meters in a utility system. The hierarchical arrangement of IEDs in the utility system is determined. Measured quantities of a characteristic of the utility being monitored are received and error-adjusted using statistical or absolute methods. The statistical method accounts for the mean and standard deviation associated with error measurements of the subject IED, and the absolute method uses the absolute value of the error measurement, expressed as a percentage, to produce ranges of measured quantities within an error tolerance. The differences between the error-adjusted quantities are analyzed to determine whether an unmonitored path exists, and if so, whether the virtual meter is consuming or supplying the utility. The order in which IEDs are read is determined so that a parent and its children are read in sequence to increase synchronicity of the received data and the virtual meter evaluation.

Abstract: A flexible amperage flag that indicates an amperage rating of a trip unit in a circuit breaker. The flag is molded with a housing of the trip unit so that it remains with the trip unit even when installed into a different circuit breaker. The flag includes an attachment member secured to a wall of the trip unit and a flexible leg integral with the attachment member. A top surface member indicates the amperage rating and protrudes through an auxiliary cover of the circuit breaker so as to be visible through the panelboard into which the circuit breaker is installed and is connected to the top surface member. During a circuit interruption, the pressure created by the exploding gas forces the auxiliary cover away from the trip unit, creating stress on the flag. The flexible leg permits the flag to move with the auxiliary cover and return to its original form without breaking.

Abstract: A voltage isolation circuit. The input voltage Vin is connected to a primary winding of a transformer T1 through a current limiting resistor R1. R1 is preferably sized such that the current flow in the primary at nominal input voltage is approximately 1 milliamp. Transformer T1 is wound as a current transformer with a fixed ratio between the primary and secondary windings. Thus, when 1 mA flows in the primary winding, 1 mA will also flow in the secondary winding. An inverting operational amplifier will continuously attempt to drive its inverting input to a zero potential through resistor R2. The voltage at Vout produced by the op-amp is a faithful replica of the voltage at Vin, but scaled according to the values selected for R1 and R2.

Abstract: A system, method, and computer program product for predicting operation for physical systems with distinct operating modes uses observable qualities of the system to predict other qualities of the system. Independent variables including temperature or production volume are observed to determine the degree to which a dependent modeled variable, including energy load, is influenced. Partition variables representing operating conditions of the dependent variables are defined as discrete values. Reference datasets with coincident values of the dependent variable, independent variable, and partition variables are received, and models are created for each discrete value of the partition variables in the reference dataset. Each model is populated with the values of the dependent variable and the independent variable. The dependent variable is modeled as a function of the independent variable.

Abstract: A method of parsing a natural language phrase to retrieve data associated with a power monitoring system. An input receives a natural language phrase including terms, one of which indicates a data manipulation action for manipulating data of the power monitoring system. A parser component parses the phrase to extract the terms and maps those terms to corresponding category items. The parser component constructs a structured query based on the category items and provides the query to a processor component that retrieves the data from a data source specified in the submitted phrase. The processor component also manipulates the data according to the data manipulation action. The output from the processor component is provided to a presentation component that formats the manipulated data for presentation on a video display, and the formatted manipulated data is displayed on the video display.

Abstract: A system for mounting and retaining an electronic device in an opening in a door or panel comprises a power monitoring device for monitoring characteristics of the power transmitted through one or more power lines. An apparatus is coupled to the power monitoring device and is adapted to secure the power monitoring device within the panel opening by engaging at least one surface of the panel. The power monitoring device may include a meter base and a display module. The combined meter base/display module assembly or remote-mounted display module may be mounted and retained in the door or panel opening.