Abstract: Apparatus for measuring the electrical energy supplied to a rail traction unit by a high voltage line (1), the apparatus comprising measurement means (5, 26) for measuring the current drawn, and measurement means (12, 27) for measuring the voltage of the power supply, said measurement means themselves possessing a low voltage power supply (23, 24) necessary to enable them to operate, the apparatus being characterized in that the low voltage electrical power supply is taken from light energy converted (22) into electrical energy.

Abstract: Communication nodes for use with a wireless ad-hoc communication network are disclosed. In an embodiment of the present invention, the communication node comprises a transducer, which generates a signal in response to an external signal. The ad-hoc network communication is supported in part by static communication nodes, which defined an organized infrastructure network in order to achieve the various functions of the transducers. In another embodiment, the communication node for use with a wireless ad-hoc network does not include a transducer. Such communication nodes are preferred for use with a less structured network with virtually no infrastructure and allow for being used with expanding and contracting networks. Mobile communication nodes mostly support the propagation of signals. However, pseudo-static or static communication nodes are also used in wireless communication ad-hoc networks.

Abstract: A modular energy meter, containing at least a power line access module, the power line access module containing at least a phase line access portion having an input end and an output end, and a zero line access portion having an input end and an output end, and at least one modular energy metering device each having a phase line input end, a zero line input end, and a phase line output end. The input end of the phase line access portion is connected to a phase line of a power line. The input end of the zero line access portion is connected to a zero line of the power line. The modular energy metering device operates to measure energy values output from a phase line output end and a zero line output end of the power line. The output end of the phase line access portion is connected to the phase line input end of the modular energy metering device. The phase line output end of the modular energy metering device is connected to a phase line output line.

Abstract: A power meter for measuring power consumption and detecting the presence of an unsafe line condition is disclosed. The power meter has a service disconnect switch, which is interposed between load contacts and source contacts, the disconnect switch interrupts the flow of power from the source contacts to the load contacts when the disconnect switch is in an open position. The power meter also has a processor coupled to a two input signal processing circuit. The two input signal processing circuit receives a first and second voltage signal from the load contacts. The two input signal processing circuit converts the first and second voltage signal into a first and second voltage value. The processor computes the power consumption using the first and second voltage values in combination with current values.

Abstract: Methods and apparatus provide for: selectively supplying a first source of power to a plurality of circuit blocks of a system using a plurality of gate circuits responsive to respective control signals provided by at least one control circuit; and providing a second source of power to operate the control circuit before the first source of power is available to the gate circuits such that the control signals are valid before such availability.

Abstract: The subject matter of this specification can be embodied in, among other things, a system that includes a computer device. The computer device includes a power supply and a component that receives power from the power supply through a first electrical connection. The system includes a measurement adapter for measuring an electrical property of the first electrical connection. The measurement adapter is interposed within the first electrical connection between the power supply and the component. The measurement adapter is configured to draw power from a second electrical connection that is different from the first electrical connection. The measurement adapter includes a sensor for measuring the electrical property of the first electrical connection.

Abstract: A method of detecting the presence of an unsafe line condition at a power metering device is disclosed. The method comprises the steps of determining if a disconnect switch is in the open position, and measuring a first voltage at a first load contact. The method measures a second voltage at a second load contact and determines if the first voltage is greater than a first voltage threshold or less than a second voltage threshold. The method further determines if the second voltage is greater than the first voltage threshold or less than the second voltage threshold. The method indicates that an unsafe condition exists if either the first voltage is greater than the first voltage threshold, or first voltage is less than the second voltage threshold or the second voltage is greater than the first voltage threshold or the second voltage is less than the second voltage threshold, when the disconnect switch is in the open position.

Abstract: A current transformer cabinet is disclosed having an electrical meter coupled to current transformers. One or more disconnect switches arranged between the source conductors and the load conductors. The disconnect switches include a link member that allows the disconnecting of electrical service from the load conductors by rotation of the link from a first position to a second position.

Abstract: An electronic energy meter includes a first sigma delta modulator having an electrically isolated digital data output. A power supply stage coupled to a first electrical line provides a supply voltage to the first sigma delta modulator. A shunt device is also coupled to the first electrical line. The first sigma delta modulator is coupled via an input to the shunt device for measuring a current through the first electrical line. The electrically isolated digital output is isolated by a capacitive isolation barrier.

Abstract: A system and method for determining the relative phase of each of a plurality of load meters connected to a three-phase power distribution system. The system includes a gateway that communicates information to and from each of the individual load meters. The gateway generates a timing pulse that is received by each of the load meters. Based upon the delay from the receipt of the timing pulse to the next zero crossing of the single phase power supply received by the meter, the utility can determine the phase of the individual meter. The system can include a feeder meter connected to each phase of the electrical supply system to determine the energy consumption for each of the meters connected to a specific phase. The utility can compare the energy consumption information from the feeder meter to all of the load meters connected to the same phase to determine whether any energy theft is occurring.

Abstract: An integrated energy metering system having an energy meter including a voltage ADC for sensing voltage, a current ADC for sensing current, a microcontroller; a first memory device for storing program data for the energy meter; and a plurality of circuit blocks; a voltage monitor for monitoring a primary power supply; a power supply switch circuit for selectively applying one of the primary and auxiliary power supplies to the energy meter; and a system controller responsive to the voltage monitor for operating the switch circuit to apply the auxiliary power supply when the primary power supply voltage decreases below a predetermined level and gating the power to a first class of circuit blocks in the energy meter and applying power continuously to a second class of circuit blocks.

Abstract: A power supply is for receiving an AC voltage and outputting a DC voltage and an output current to an electronic device. The power supply includes an input module, an output module, a measuring interface, a measuring interface, and a switch module. The input module is for receiving the AC voltage. The output module is for outputting the DC voltage and the output current to the electronic device. The measuring interface is for electrically contacting with a part of the electronic device. The measuring module is for measuring the DC voltage, the output current, and a voltage and a current of the part of the electronic device. The switch module is for choosing one of the output module and the measuring interface to be electrically connected to the measuring module.

Abstract: A system and method of monitoring a plurality of electrical assets comprise an electricity distribution infrastructure, including a plurality of electrical asset sensors coupled to the electrical assets for monitoring an operating condition of the electrical assets as well as any fault conditions. The sensors may include a current transformer for obtaining a current waveform, a GPS receiver for applying a synchronized time-stamp to the waveform data, and a mesh network radio for transmitting the time-stamped waveform data. Data from the plurality of sensors may be encrypted and transmitted over a mesh network to one or more gateways that are in communication with a central command processor. In response to an abnormal operating condition of any electrical asset, the central command processor may determine a probable fault location, a probable fault type, and a fault response.

Abstract: An integral electronic revenue meter system diagnostics package including a microprocessor, storage memory, preselect series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period is included as part of an electricity revenue meter of the type used for collecting metering data for a utility which uses such data for billing purposes. The system automatically senses the type of electrical service in which the revenue meter is installed when the revenue meter is installed in a socket at the customer's premises.

Abstract: A load measuring circuit including a cable including first and second conductors and a shielding. The conductors are connected by a first end thereof to a load, the shielding is not connected to a ground at the end, and the conductors are connected to a generator by the second end thereof. A transformer includes a first winding connected to a conductor on the second end of the cable, a second winding is connected between a ground and the shielding on the second end of the cable, and a third winding is connected to a current measuring member.

Abstract: A method of testing power-on reset circuitry in an integrated circuit comprises establishing the a first state of the integrated circuit that is different from a normal reset state of the circuit, lowering the VCC power supply voltage from a normal high operating level VH to a specified lower level VP then raising it back to the normal high level, then determining whether or not the integrated circuit has assumed the reset state. The testing can repeated with a plurality of lower VCC levels VP and under a variety of operating conditions to characterize resetting parameters and to designate pass/fail results for individual chips. If an AC voltage detector is part of the power-on reset circuitry, then it can tested separately, and DC testing occurs with very slow ramp rates for lowering and raising the power supply voltage.

Abstract: A modular electricity meter configuration and corresponding methodology permits use of certain common components in combination with either a variety of mechanical displays or electronic displays. In electricity meter arrangements making use of printed circuit board or solid state technology, at least two separate electronics boards may be provided. One may constitute a standard board for basic metrology functions while the other may comprise selected implementation of various higher level functions for creating a custom design electricity meter to meet customer requirements. Different customers may be provided with differently outfitted meters by corresponding customization of the higher level function board. A unitary power supply may be provided for both boards through a fixed connector. A common baseplate includes a circuitry link through a nonremovable plug or clip for alternatively providing a tamper proof embodiment or one with exposed terminals for permitting customer testing.

Abstract: An integral electronic revenue meter system diagnostics package including a microprocessor, storage memory, preselect series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period is included as part of an electricity revenue meter of the type used for collecting metering data for a utility which uses such data for billing purposes. The system automatically senses the type of electrical service in which the revenue meter is installed when the revenue meter is installed in a socket at the customer's premises.

Abstract: An integral electronic revenue meter system diagnostics package including a microprocessor, storage memory, preselect series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period is included as part of an electricity revenue meter of the type used for collecting metering data for a utility which uses such data for billing purposes. The system automatically senses the type of electrical service in which the revenue meter is installed when the revenue meter is installed in a socket at the customer's premises.

Abstract: A signal transmission device is disclosed, which serves to connect a measuring probe, in particular a pH measuring probe or an oxygen measuring probe, to a signal-processing unit. The signal transmission device includes a differential amplifier at whose non-inverting input an input signal can be applied which is provided by an electrode of the measuring probe, and from which a corresponding low-impedance output signal can be delivered to a transmission line, by which the output signal can be transmitted to the signal-processing unit. The output of the differential amplifier can be connected via a first resistor to the transmission line and to the inverting input of the differential amplifier, and can be connected to the input of a first control unit by which signals can be registered, such as clock signals and/or data, which are applied to the transmission line by the signal-processing unit.

Abstract: An automatic method of which days/hours represent good candidates for reducing demand to achieve potential savings and the amount of demand reduction that can be achieved with a tolerable level of disruption to status quo operations. Demand interval data including utility usage rate (UUR) values is received from one or more utility monitoring devices, and are sorted in descending order. A percent difference is calculated for each UUR value relative to the previous one, and a cumulative percent difference accumulates the percent differences from the preceding rows. The average cumulative percent difference is divided by the total number of UUR values in the measured period to produce a ratio. The standard deviation of time is determined, and from those demand data associated with ratios greater than a ratio threshold and standard deviations less than a standard deviation threshold the demand reduction amount and the number of control hours are determined.

Abstract: A panel meter including an energy test pulse device that enables the panel meter to be used for revenue applications and eliminates the need for two separate meters, one for panel indication, and the other for energy and revenue applications. The electrical panel meter including at least one sensor configured for measuring an electrical parameter; at least one analog-to-digital converter coupled to the at least one sensor for converting the measured electrical parameter to a digital signal; a display for continuously displaying at least one electrical parameter; a processor configured to receive the digital signal and calculate an amount of energy consumed; and a test pulse circuit configured to receive the calculated amount and generate a plurality of pulses equal to the calculated amount, wherein each of the plurality of pulses is equal to a predetermined amount of energy.

Abstract: An arrangement for use in connection with an electricity meter includes an electricity meter housing and at least one connection between a first conductor and a second conductor carrying line voltage. The arrangement further includes a processing circuit that is configured to obtain a first voltage measurement within the meter housing on a first side of the at least one connection, and to obtain a second voltage measurement on a second side of the at least one connection. The processing circuit is further configured to determine a value corresponding to an impedance across the at least one connection.

Abstract: An arrangement includes a utility meter housing that contains or supports a first sensor, a second sensor, and a processing circuit. The first sensor is configured to measure a first parameter, the first parameter relating to an environmental condition within the meter housing. The second sensor is configured to measure a second parameter. The processing circuit is operably connected to the first sensor and to the second sensor, and is configured to record information relating to one or more events, each event corresponding to a detection of an out of range condition by each of the first sensor and the second sensor.

Abstract: An electric meter comprises an electronics housing and a meter base. The electronics housing defines a front panel and includes a first plurality of option board guides. A main meter board is disposed substantially parallel to the front panel. The meter base defines a rear panel of the electric meter. The meter base includes a plurality of housing guides for receiving the electronics housing and a second plurality of option board guides disposed substantially perpendicularly to the rear panel. The second plurality of option board guides are adapted to receive an option board and to position the option board substantially perpendicularly to the main meter board of the electronics housing during assembly of the electronics housing to the meter base. The housing guides in combination with the first and second pluralities of option board guides enable blind assembly of the electronics housing to the meter base.

Abstract: A method of monitoring the electrical power in multiple branch circuits of an AC electrical power distribution system comprises monitoring at least one voltage common to said multiple branch circuits using a main meter unit, monitoring currents of the multiple branch circuits using multiple current cards that receive a plurality of current inputs from current transducers in the multiple branch circuits, sampling the monitored voltage in the main meter unit and the monitored currents in the current cards multiple times in each cycle of the AC power signal, determining the magnitudes and angles of spectral components of the sampled current in the current cards, sending data representing the magnitudes and angles of at least selected spectral components from the current cards to the main meter unit, and storing the voltage samples and the magnitudes and angles of at least the selected spectral components in the main meter unit.

Abstract: An integral electronic revenue meter system diagnostics package including a microprocessor, storage memory, preselect series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period is included as part of an electricity revenue meter of the type used for collecting metering data for a utility which uses such data for billing purposes. The system automatically senses the type of electrical service in which the revenue meter is installed when the revenue meter is installed in a socket at the customer's premises.

Abstract: A polyphase electricity meter comprising a metering system allowing to measure a flow of electricity through a plurality of phases of a portion of an electricity network. The electricity meter further comprises a rechargeable powering system allowing to power at least the metering system. The rechargeable powering system is charged by at least one phase of the electricity network.

Abstract: Power consumption at a site is monitored. An electrical load is connected to a power source by an electrical conductor. A fuel-less energy producing device is electrically connected to a junction along the electrical conductor. A current sensor is electromagnetically coupled to the electrical conductor at a sensing position between the power source and the junction to create a current sensor signal. Sensed current and voltage signals are produced from the current sensor signal. A sensed phase relationship between the sensed signals is determined and compared to a baseline phase relationship to determine the direction of current flow through the conductor. A power source signal, based on the current flowing through the conductor at the sensing position, is created. With some examples a Rogowski type differential current sensor is used. In some examples a single current sensor is used.

Abstract: Disclosed is a wedge shaped actuator device configured to provide separation of spring supported electrical contacts in an electrical switch. The wedge is configured with dual contour sides to maximize transfer of energy from a drive solenoid to the contact carrying springs. Portions of the wedge are relieved to allow for uninhibited movement of the wedge over side surfaces of the contact carrying springs to avoid digging in of any rough materials from the side edges of the spring as may be occasioned due to stamping techniques used to form the springs.

Abstract: A self-powered alternating current measuring and power generating circuit is designed to be connected across the terminals of the secondary winding of a current transformer. The circuit includes a current to voltage transformer, the primary winding of which is connected in series at a junction with a resistor across the terminals of the secondary winding of the current transformer. The junction of the resistor and the primary winding of the current to voltage transformer is supplied to a measuring circuit to produce an output coupled to a measuring instrument. Operating power for the measuring circuit is obtained from the secondary winding of the current to voltage transformer through a rectifier; so that the circuitry is energized without requiring additional internal or external power sources.

Abstract: Power consumption at a site is monitored. An electrical load is connected to a power source by an electrical conductor. A fuel-less energy producing device is electrically connected to a junction along the electrical conductor. A current sensor is electromagnetically coupled to the electrical conductor at a sensing position between the power source and the junction to create a current sensor signal. Sensed current and voltage signals are produced from the current sensor signal. A sensed phase relationship between the sensed signals is determined and compared to a baseline phase relationship to determine the direction of current flow through the conductor. A power source signal, based on the current flowing through the conductor at the sensing position, is created. With some examples a Rogowski type differential current sensor is used. In some examples a single current sensor is used.

Abstract: A metering device for metering energy delivered to customers over electrical wires from a power distribution cabinet. The metering device has a plurality of current transformers, each capable of receiving one of the electrical wires and connections for the line voltages which drive the wires. The current transformers are arranged for physical correspondence to the power outputs of the power distribution cabinet. Circuitry connected to the current transformers and line voltage connections meter the energy over the electrical wires.

Abstract: A modular electricity meter configuration and corresponding methodology permits use of certain common components in combination with either a variety of mechanical displays or electronic displays. In electricity meter arrangements making use of printed circuit board or solid state technology, at least two separate electronics boards may be provided. One may constitute a standard board for basic metrology functions while the other may comprise selected implementation of various higher level functions for creating a custom design electricity meter to meet customer requirements. Different customers may be provided with differently outfitted meters by corresponding customization of the higher level function board. A unitary power supply may be provided for both boards through a fixed connector. A common baseplate includes a circuitry link through a nonremovable plug or clip for alternatively providing a tamper proof embodiment or one with exposed terminals for permitting customer testing.

Abstract: An electrical phase checking apparatus includes a first voltage sensor, a first current sensor, a first binary indicator corresponding to the first voltage and current sensors, a second voltage sensor, a second current sensor, and a second binary indicator corresponding to the second voltage and current sensors. The first binary indicator is configured to indicate when a phase separation between a voltage waveform measured by the first voltage sensor and a current waveform measured by the first current sensor is not more than a first value, and the second binary indicator is configured to indicate when a phase separation between a voltage waveform measured by the second voltage sensor and a current waveform measured by the second current sensor is not more than a second value.

Abstract: An energy consumption meter includes a first input for providing a first input signal derived from a voltage, a first analog-to-digital (A/D) converter electrically connected to the first input to generate a first output signal based on the first input signal, a second input for providing a second input signal derived from a current, a second A/D converter electrically connected to the second input to generate a second output signal based on the second input signal, a multiplier to combine signals corresponding to the first and second output signals, and a phase evaluation block having two inputs that are electrically connected to the first input and to the second input. The phase evaluation block measures a phase difference that corresponds to a phase difference between the first input signal and the second input signal. A phase correction block corrects for the phase difference in one of the first output signal and the second output signal.

Abstract: In a watt-hour meter, encoders 116, 117, 118 and 119 respectively convert a signal concerning a current and voltage used by a customer into a code sequence signal by Reed-Solomon codes or convolutional codes. Decoders 121, 122, 123, and 124 reversely convert the code sequence signal to the signal concerning the current and voltage. A power calculating section 125 converts the signal concerning the current and voltage into data concerning electricity consumption.

Abstract: A power meter has a measuring circuit composed entirely of analog components that measures the instantaneous current draw of one or more electrical devices, such as home appliances. The power meter may be in the form of a hand-held device that includes elongated connections that allow a homeowner to measure the current draw of an electrical device without significant displacement of the electrical device. In addition to measuring current draw, the power meter may provide an estimated wattage consumed by the measured electrical devices.

Abstract: A panel meter including an energy test pulse device that enables the panel meter to be used for revenue applications and eliminates the need for two separate meters, one for panel indication, and the other for energy and revenue applications. The electrical panel meter including at least one sensor configured for measuring an electrical parameter; at least one analog-to-digital converter coupled to the at least one sensor for converting the measured electrical parameter to a digital signal; a display for continuously displaying at least one electrical parameter; a processor configured to receive the digital signal and calculate an amount of energy consumed; and a test pulse circuit configured to receive the calculated amount and generate a plurality of pulses equal to the calculated amount, wherein each of the plurality of pulses is equal to a predetermined amount of energy.

Abstract: Systems and methods for producing power consumption data enabling up-to-the-minute automatic collection and transmission of real-time energy flow information are described. Energy consumption from a source of electricity by an electrical device may be measured. This measured data may then be stored for later transmission on a wireless network. Additionally, energy consumption data from another measurement device may be received and stored or retransmitted until it reaches a gateway where it is harvested. The harvested data may be stored and organized for display to a user. Embodiments may allow for a low-cost high precision integrated power meter IC in combination with a low-cost radio transceiver chip to control part count and cost of power monitoring node implementation to provide for internet-based power monitoring, management and analysis at any level of granularity. Other embodiments are described and claimed.

Abstract: A magnetic core for a current transformer, and a current transformer and a watt hour meter used thereof, which is preferred the detection of a alternate current with a large asymmetrical waveform and a alternate current which a direct current is superimposed are realized. A magnetic core for a current transformer comprising the composition represented by the general formula: Fe100-x-a-y-cMxCuaM?yX?c (atomic %), wherein M is at least one element selected from Co and Ni, M? is at least one element selected from V, Ti, Zr, Nb, Mo, Hf, Ta, X? is at least one element selected from Si and B, and x, a, y, and c meets the composition of 3?x?50, 0.1?a?3, 1?y?10, 2?c?30, and also 7?y+c?30, and an alloy comprising a crystal grain consisting of at least a part or all of the composition with a mean particle size of less than or equal to 50 nm.

Abstract: A test switch is provided having front and rear sides. The test switch includes a base to which a plurality of switch units are mounted. A row of upper terminals are removably mounted to the base, above the switch units, and a row of lower terminals are removably mounted to the base below the switch units. The upper and lower terminals are adapted for connection to wiring from the front side of the test switch. Upper and lower covers are releasably attached to the base and extend across the rows of upper and lower terminals, respectively.

Abstract: An intelligent electronic device for monitoring and determining an amount of electrical power usage by a consumer, or end user, and for providing broadband Internet access to the consumer. The intelligent electronic device includes at least one sensor coupled to an electric circuit configured for measuring at least one power parameter of the electrical circuit and generating at least one analog signal indicative of the at least one power parameter; at least one digital to analog converter coupled to the at least one sensor configured for receiving the at least one analog signal and converting the at least one analog signal to at least one digital signal; a processor configured for receiving the at least one digital signal and calculating energy consumption in the electrical circuit; and a gateway configured for receiving data transmissions imposed on the electrical circuit and for demodulating the imposed data transmission for providing data communications.

Abstract: Devices and methods for accurately realizing the integration functions, in particular for energy metering systems using a Rogowski coil, are disclosed. In this regard, exemplary embodiments of the present invention may be constructed as two stable filters for the current (I) and voltage (U) channel. In the analog realization form, the transfer function of the voltage channel may be constructed as a high-pass filter function with at least one zero at the origin, while the transfer function of the current channel may be constructed as the multiplication of the high-pass filter function of the voltage channel and the ideal analog integration function.

Abstract: An electricity meter coupled to a load, the load coupled to electrical power lines includes a sensor module having a sensor housing, voltage and current sensors secured within the sensor housing and a service disconnect switch secured within the housing. The voltage and current sensors are operable to receive voltage and current signals representative of voltage and current provided to the load and generate measurements signals therefrom. The service disconnect switch is operable to controllably disconnect and connect the load to the electrical power lines. The meter further includes a removable measurement module including a measurement circuit operable to receive the measurement signals and generate energy consumption data therefrom. The measurement module includes a device for communicating information relating to the energy consumption data. The measurement module is configured to be coupled to the sensor module to connect the measurement circuit to the voltage and current sensors.

Abstract: An electricity meter capable of minimizing a risk of data destruction in case of lightning or surge that involves improperly high voltage is provided. The electricity meter includes a measurement part, an operation part, and an insulation part. The measurement part includes a detection unit to detect electricity consumption of an objective system and a transmission unit to wirelessly transmit data representative of the detected electricity consumption. The operation part includes a reception unit to receive the wirelessly transmitted data and an operation unit to process the received data into data representative of electric energy consumed by the objective system. The insulation part electrically insulates the measurement part and operation part from each other.

Abstract: A calibration technique provides for precision calibration of system power measurement. The calibration technique uses a precision reference resistor and voltage reference controlled current source to introduce a voltage drop from the input side of a power supply sense resistor. Calibration measurements are thereby made for voltages substantially equal to the voltage of the power supply output, so that differential measurements are made at substantially the same common-mode voltage by appropriate selection of the relationship of the resistance of the precision reference resistor and the resistance of the sense resistor, where the common-mode voltage of the measurement is substantially equal to the power supply output voltage.

Abstract: An electronic energy meter includes a first sigma delta modulator having an electrically isolated digital data output. A power supply stage coupled to a first electrical line provides a supply voltage to the first sigma delta modulator. A shunt device is also coupled to the first electrical line. The first sigma delta modulator is coupled via an input to the shunt device for measuring a current through the first electrical line. The electrically isolated digital output is isolated by a capacitive isolation barrier.

Abstract: A metering device for metering energy delivered to customers over electrical wires from a power distribution cabinet. The metering device has a plurality of current transformers, each capable of receiving one of the electrical wires and connections for the line voltages which drive the wires. The current transformers are arranged for physical correspondence to the power outputs of the power distribution cabinet. Circuitry connected to the current transformers and line voltage connections meter the energy over the electrical wires.

Abstract: A metering module for use in a power circuit monitoring system including a circuit monitor having a processor for processing data related to power signals, said metering module comprising at least one sensor for sensing a predetermined property of a power signal and for producing a corresponding sensor signal, and a modular metering circuit for producing data corresponding to said sensor signal for input into said circuit monitor, wherein said metering module is selectively detachable and replaceable relative to said circuit monitor to permit one or more of testing, calibration and repair of said metering module thereby minimizing any interruption in operation of said circuit monitor.