An arrangement for use in a utility meter includes at least one circuit path, a three phase service switch, and a three phase monitoring unit. The at least one circuit path operably couples a source of electrical energy to a load. The service switch is operably coupled to the at least one circuit path and is configurable in an open state and a closed state. The monitoring unit is operably coupled to the at least one circuit path between the load and the service switch and is configured to detect a presence and an absence of line voltage on the load. The monitoring unit is further configured (i) to generate an open circuit signal responsive to the detection of the absence of line voltage on the load, and (ii) to generate a closed circuit signal responsive to the detection of the presence of line voltage on the load.
G01R 22/00 - Arrangements for measuring time integral of electric power or current, e.g. electricity meters
G01R 35/02 - Testing or calibrating of apparatus covered by the other groups of this subclass of auxiliary devices, e.g. of instrument transformers according to prescribed transformation ratio, phase angle, or wattage rating
G01R 35/04 - Testing or calibrating of apparatus covered by the other groups of this subclass of instruments for measuring time integral of power or current
An arrangement for use in a utility meter includes at least one circuit path, a three phase service switch, and a three phase monitoring unit. The at least one circuit path operably couples a source of electrical energy to a load. The service switch is operably coupled to the at least one circuit path and is configurable in an open state and a closed state. The monitoring unit is operably coupled to the at least one circuit path between the load and the service switch and is configured to detect a presence and an absence of line voltage on the load. The monitoring unit is further configured (i) to generate an open circuit signal responsive to the detection of the absence of line voltage on the load, and (ii) to generate a closed circuit signal responsive to the detection of the presence of line voltage on the load.
A utility meter configured for connection to an AC power line includes a meter housing with a plurality of electronic components arranged within the meter housing and configured to provide consumption data. A power supply is also arranged within the meter housing. The power supply is configured to receive an AC voltage from the AC power line and supply a DC voltage to the electronic components. An AC line voltage booster is positioned connected to the power supply. The AC line voltage booster is configured to increase the voltage from the AC power line received by the power supply.
A method is used in a utility meter having an arm bit and a seal bit. The method includes changing a state of the arm bit to a first state in response to a first set of conditions. The method also includes removing electrical power from the meter. Upon subsequently applying electrical power to the meter, a first signal in a meter processing circuit indicates whether a meter cover is installed or the meter cover is removed. The processing circuit changes the seal bit to a first state responsive to a condition in which the arm bit is in the first state and the first signal indicates that the meter cover is installed. The processing circuit changes the seal bit to a second state responsive to a condition in which the seal bit is in the first state and the first signal indicates that the meter cover is removed.
A tamper detection system for an electricity meter includes an antenna, an RF signal level circuit, and a controller. The antenna is configured to receive an RF signal. The RF signal level circuit is supported within an electricity meter housing and is operatively connected to the antenna. The RF signal level circuit is configured to detect the RF signal received by the antenna and to provide a strength signal corresponding to a magnitude of the RF signal. The controller is supported within the electricity meter housing, and is operatively connected to the RF signal level circuit. The controller is configured to generate an RF signal strength value based at least in part on the strength signal, and to generate a tamper flag responsive at least in part to a determination that the RF signal strength value exceeds a threshold value.
An arrangement for use in a utility meter (10) includes a sensor (18) and a processing circuit (14) supported by a base of the meter (10), and a magnetic element (24) carried by the cover (22) of the meter, in which the cover (22) is removably mounted to the base. The sensor (18) includes at least two magnetizable elements (102,103), such as inductors, that are magnetized at opposite polarities when the meter (10) is closed and operable. The magnetizable elements (102,103) are positioned in very close proximity so that as cover (22) is removed the magnetic element (24) passes the elements (102,103) to cause the magnetizable elements (102,103) to assume the same polarity. The processing circuit (14) continuously polls the magnetizable elements (102,103) to evaluate their respective polarities and is configured to issue a tamper indication when the detected polarities are the same.
An arrangement for use in a utility meter (10) includes a sensor (18) and a processing circuit (14) supported by a base of the meter (10), and a magnetic element (24) carried by the cover (22) of the meter, in which the cover (22) is removably mounted to the base. The sensor (18) includes at least two magnetizable elements (102,103), such as inductors, that are magnetized at opposite polarities when the meter (10) is closed and operable. The magnetizable elements (102,103) are positioned in very close proximity so that as cover (22) is removed the magnetic element (24) passes the elements (102,103) to cause the magnetizable elements (102,103) to assume the same polarity. The processing circuit (14) continuously polls the magnetizable elements (102,103) to evaluate their respective polarities and is configured to issue a tamper indication when the detected polarities are the same.
A method of detecting a magnetic coupling in a meter includes obtaining in an electricity meter information representative of power consumption as measured within the meter of a plurality of lines (103) of an electrical service. The method also includes obtaining from a magnetic sensor (108) information representative of a magnetic field within an electricity meter (100). A processing circuit (112) then determines whether a first condition exists wherein the magnetic field exceeds a first threshold and the information representative of the power consumption indicates a load imbalance on the plurality of lines such that the load imbalance exceeds an imbalance threshold. The method further includes performing a processing step responsive to a determination that the first condition exists.
A method measures a resistance of an element (120a, 120b) that is operably coupled to receive an AC line voltage. The method includes obtaining a first voltage measurement value V1A from a first side of the element at a first time, and obtaining a second voltage measurement value V2A from a second side of the element at the first time. The method also includes obtaining a first current measurement value IA through the element at the first time, and obtaining a second current measurement value IB through the element at the second time. The method further includes obtaining a third voltage measurement value VIB from the first side of the element at a second time, and obtaining a fourth voltage measurement value V2B from the second side of the element at the second time. A processing device (118) determines the resistance at least in part based on the values V1A,V2A V1B, V2B, IA and IB. The determination is based on an adjusted difference of V2B and V2A.
An arrangement includes an A/D converter and a processing circuit. The A/D converter is configured to generate digital samples of voltage and current waveforms in a polyphase electrical system. The processing circuit is operably coupled to receive the digital samples from the A/D converter. The processing circuit configured is to obtain contemporaneous phase current and voltage samples IA, IB, IC and/or IN, and VA, VB, VC. The processing circuit is further configured to determine at least ICB sample values based on three of the current samples of IA, IB, IC, and IN, and determine a VA value based at least in part on ICB. The processing circuit is further configured to provide information representative of the VA calculation to one of a group consisting of a display, a communication circuit, a memory and a billing calculation unit.
A method for storing information within a utility meter includes generating in a processing circuit first information regarding a metered quantity delivered to a load corresponding to a first period of time. The method also includes obtaining a first value associated with one of a plurality of predetermined ranges of values in which the first information falls. The method further includes generating in a processing circuit a second value representative of a numerical position of the first information within the one of the plurality of predetermined ranges of values. The first value and the second value are stored in a memory.
A circuit arrangement for use in a utility meter includes a mechanical switch, a processor device, and a latch circuit. The mechanical switch has a closed position and an open position, and is supported by a meter housing. The mechanical switch is operably coupled to generate a close signal when the mechanical switch is in the closed position. The processor device has a first processor input and a second processor input. The first processor input is operably coupled to receive the close signal. The latch circuit is operably coupled to receive the close signal and generate a latched signal responsive thereto. The latch circuit is configured to latch the latched signal for a predetermined time, the predetermined time corresponding to a wake-up time of the processor device. The latch circuit is operably coupled to provide the latched signal to the second processor input.
An arrangement for controllably disconnecting a utility power service from a load (25) includes a utility meter housing (105), a switch (104) and a processing circuit (110). The utility meter housing (105) includes metrology circuitry (102) configured to generate metering information regarding electrical power provided to the load (25). The switch (104) is configured to controllably interrupt a connection between the utility power service and the load (25). The switch (104) has an open state and a closed state. The processing circuit (110) is configured to determine whether a line voltage varies from an expected value by more than a predetermined amount over a predetermined amount of time. The processing circuit (110) is further configured to cause a change in state of the switch (104) based on the determination.
H02J 13/00 - Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the networkCircuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
G01R 22/06 - Arrangements for measuring time integral of electric power or current, e.g. electricity meters by electronic methods
A utility meter comprises a measurement circuit configured to measure consumption data, a memory configured to store meter data including the consumption data, and a receiver configured to receive a priority message from a source external to the utility meter. A meter display on the meter comprises a plurality of display segments. The meter display is configured to display the meter data according to a standard meter display routine. The meter display is further configured to display the priority message on at least a first portion of the plurality of display segments such that meter data normally displayed during the standard meter display routine is not displayed on the first portion of the plurality of display segments. A meter controller is configured to determine whether the standard meter display routine should be interrupted or overridden in order to display the remote message.
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