Abstract: A method and apparatus is disclosed for providing protection against arc flash during maintenance on a low voltage power circuit including a circuit breaker having a specified trip function for responding to a fault is provided. The specified trip function is overridden with a maintenance trip function that results in reduced arc energy in the fault during a trip over arc energy during a trip with the specified trip function. The specified trip function is restored following maintenance.

Abstract: A circuit protection system is provided that utilizes a single state definition for each of the zones of protection of the circuit to increase computational efficiency. Multiple zone protective functions can be performed on a single zone of protection and can reference the single state definition.

Abstract: A centrally controlled protection system is provided. The system includes a plurality of circuit breakers, a plurality of modules, and a central computer. Each of the plurality of breakers are in electrical communication with a respective one of the plurality of modules. The central computer is in communication with each of the plurality of modules via a network. The central computer controls the plurality of circuit breakers in either a normal mode or a reduced energy let-through mode.

Abstract: A circuit protection system is provided that provides dynamic zones of protection for the circuit. The zones of protection can be based in part upon the topology of the circuit. The protection system can perform various dynamic zone protective functions for the zones of protection.

Abstract: A method of operating a relay device, in an electrical circuit comprising first and second main circuit breakers, and a bus tie circuit breaker connecting the first and second main circuit breakers, the method comprising computing a first positive sequence current phasor for the first main circuit breaker and a second positive sequence current phasor for the second main circuit breaker computing a first positive sequence voltage phasor for the first main circuit breaker and a second positive sequence voltage phasor for the second main circuit breaker; computing a correction of the first positive sequence voltage and second positive sequence voltage to a line-to-neutral phase angle reference if there is any rotation in a potential transformer connection; determining a fault has occurred when a magnitude of a current through at least one of the first main circuit breaker or the second main circuit breaker exceeds a predetermined threshold; determining a phase angle difference by comparing the phase angle of the

Abstract: A method of operating a relay device, the method comprising the steps of: providing main circuit-breakers and a bus-tie-breaker connecting the main-circuit-breakers; defining a partial-differential-zone comprising a main circuit breaker and the bus-tie breaker; assigning a first value to the direction of the fault current flowing into the partial differential zone;—assigning a second value to the direction of the fault currents flowing out of the partial-differential-zone, wherein the first value is not equal to the second value;—comparing the values assigned to the fault currents; determining if the fault currents are flowing into the partial differential zone; and determining if at least two of the fault-currents is flowing in a different direction with respect to the partial-differential-zone wherein one of the fault currents is flowing into the partial-differential-zone and one of the fault currents is flowing out of the partial differential zone.

Abstract: A method of operating a relay device, the method comprising the steps of: providing main circuit-breakers and a bus-tie-breaker connecting the main-circuit-breakers; defining a partial-differential-zone comprising a main circuit breaker and the bus-tie breaker; assigning a first value to the direction of the fault current flowing into the partial differential zone; -assigning a second value to the direction of the fault currents flowing out of the partial-differential-zone, wherein the first value is not equal to the second value; -comparing the values assigned to the fault currents; determining if the fault currents are flowing into the partial differential zone; and determining if at least two of the fault-currents is flowing in a different direction with respect to the partial-differential-zone wherein one of the fault currents is flowing into the partial-differential-zone and one of the fault currents is flowing out of the partial differential zone.

Abstract: A method of operating a relay device, the method comprising the steps of: computing positive-sequence first and second current-phasor for the first and second main circuit-breakers and computing currents from phasors, and the bus-tie-breaker; computing positive-sequence voltage for the bus-tie-breaker; triggering a method when at least one fault current at the bus-tie-breaker exceeds a threshold, without the presence of a fault on one of the feeders; determining whether the fault is internal or external, wherein the fault is internal if the positive-sequence current of the first and second main circuit breakers is in phase; and wherein if the positive-sequence current through the first main circuit breaker is not in-phase with the positive-sequence current through the second main circuit breaker, the fault is external to the bus; determining whether the fault is on a first or second side of the tie circuit; and locating the fault.

Abstract: A circuit protection system is provided that provides a dynamic delay time to an upstream circuit breaker if a fault is detected in a circuit where the dynamic delay time can be based upon the location of the fault, such as the nearest downstream circuit breaker. A control processing unit can determine a dynamic delay time for opening a first circuit breaker if a fault is detected in the circuit. The control processing unit delays opening the first circuit breaker until after the dynamic delay time has elapsed to provide an opportunity for the nearest circuit breaker to clear the fault.

Abstract: The present invention, in one embodiment, is a method for operating an electronic electric meter having current and voltage sensors configured to generate measurements of current and voltage, respectively; a microcomputer coupled to the current and voltage sensors and having on-chip masked read only memory (ROM); and a nonvolatile, alterable memory coupled to the microcomputer. The method includes steps of: storing vectors pointing to program portions of the ROM in the non-volatile memory; and using the stored vectors to operate the microcomputer to execute the program portions stored in the ROM to control operation of the meter.

Abstract: A method of performing energy calculations in a power distribution system is provided. The method includes sampling a first voltage at a first module in the power distribution system; communicating the first voltage from the first module to a central controller; performing an energy calculation in the central controller based at least in part on the first voltage; and applying the energy calculation to a second module in the power distribution system. In some embodiments, the energy calculation is also based upon a second current from the second module.

Abstract: In order to detect high-speed transients in the alternating current of a power distribution system, the rate at which the power on the distribution system is sampled is increased so that even high-speed transients are detected. The sampling rate can be increased in at least two ways. First, where a single analog-to-digital converter samples multiple lines through a multiplexer, the multiplexer is controlled to allow the converter to sample only one line at a much-increased rate. Alternatively, the sampling speed of the analog-to-digital converter (or A/D array) can be controlled and increased as needed.

Abstract: A data sample and transmission module for a power distribution system having a microprocessor, a locator device, and a network interface is provided. The microprocessor samples one or more first signals indicative of a condition of power in the power distribution system. The locator device is changeable between a first state and a second state. The network interface can place the microprocessor in communication with a network so that the microprocessor samples the first signals based in part upon a synchronization signal receivable from the network and so that the locator device changes from the first state to the second state in response to a command receivable from the data network.

Abstract: An apparatus and method for creating a secure program history log for a programmable device including a microprocessor, at least one communications port for communicating with the microprocessor and at least one memory device electrically connected to the microprocessor. The memory device includes a program history log, and the method includes communicating program parameters to the microprocessor, creating a log entry utilizing the microprocessor and the program parameters, and writing the log entry into the program history log utilizing the microprocessor.

Abstract: The present invention, in one embodiment, is a method for metering energy consumption with an electric meter. The method includes steps of: generating metering quantities for a plurality of phase voltages from a multiphase voltage source, including generating revenue-related data; monitoring voltage changes on at least one of the phase voltages; and performing a predetermined task in response to a voltage change on at least one of the phase voltages while continuing to generate revenue-related data.

Abstract: A circuit protection system is provided that utilizes a single state definition for each of the zones of protection of the circuit to increase computational efficiency. Multiple zone protective functions can be performed on a single zone of protection and can reference the single state definition.

Abstract: A circuit protection system is provided that provides dynamic zones of protection for the circuit. The zones of protection can be based in part upon the topology of the circuit. The protection system can perform various dynamic zone protective functions for the zones of protection.

Abstract: A method of performing energy calculations in a power distribution system is provided. The method includes sampling a first voltage at a first module in the power distribution system; communicating the first voltage from the first module to a central controller; performing an energy calculation in the central controller based at least in part on the first voltage; and applying the energy calculation to a second module in the power distribution system. In some embodiments, the energy calculation is also based upon a second current from the second module.

Abstract: A data sample and transmission module for a power distribution system having a microprocessor, a locator device, and a network interface is provided. The microprocessor samples one or more first signals indicative of a condition of power in the power distribution system. The locator device is changeable between a first state and a second state. The network interface can place the microprocessor in communication with a network so that the microprocessor samples the first signals based in part upon a synchronization signal receivable from the network and so that the locator device changes from the first state to the second state in response to a command receivable from the data network.

Abstract: A circuit protection system is provided that provides a dynamic delay time to an upstream circuit breaker if a fault is detected in a circuit where the dynamic delay time can be based upon the location of the fault, such as the nearest downstream circuit breaker.