US 4,827,369 AGranted

Circuit interrupter apparatus with a selectable display means

AssigneeWestinghouse Electric Corp.

InventorsGary F. Saletta, Joseph J. Matsko

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Abstract

A circuit interrupter includes a circuit arrangement for sampling a conditioned current value and determining operating characteristics related to the current flow through an electrical circuit. Also included is a circuit arrangement for comparing the operating characteristics to preselectable tripping parameters and circuit arrangement for initiating a trip condition when an operating characteristic exceeds a corresponding tripping parameter. Additionally, a circuit arrangement for selecting and displaying operating information in an understandable format and in an easily accessible position on the circuit interrupter is also included.

Claims24

Dependent claims

A circuit interrupter apparatus, comprising:

interrupting means disposed in a normally conducting electrical circuit and effective to interrupt current flow through said electrical circuit upon reception of a trip signal;
conditioning means coupled to said electrical circuit to condition a current value proportionate to said current flow, said conditioning means producing a conditioned signal representative of the magnitude of said current value;
operating means effective for sampling said conditioned signal at a predetermined frequency and for deriving therefrom, at least one measurement representative of said at least one operating characteristic, said operating means further being effective for comparing, after a preselected sequence of sampling events, said at least one measurement derived from said at least one operating characteristic to a corresponding at least one preselected tripping parameter as represented by a trip curve and generating said trip signal when said at least one operating characteristic is at least equal to said corresponding at least one preselected tripping parameter, said operating means including a processor element which has a memory portion associated therewith;
display means coupled to said operating means for selectively displaying a value proportionate to said at least one operating characteristic, said display means further including indicating means for identifying said value that has been displayed;
and
wherein said at least one measurement that said operating means derives from said conditioned signal is proportionate to at least one RMS value and further wherein, at times when said at least one measurement is associated with said current flow in said electrical circuit, said at least one RMS value is at least a first and a second RMS value measured at different time durations which at least partially coincide and during said timely sampled values of said conditioned signal are summed such that, at least a first and a second summation result therefrom which can be stored in at least two separate memory locations of said memory portion of said processor element, said operating means further being effective for performing a mathematical operation on said at least said first and second summations to derive said measurements which are proportionate to said at least said first and second RMS values.

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Dependencies are inferred from the claim text.

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Abstract

A circuit interrupter apparatus, comprising:

interrupting means disposed in a normally conducting electrical circuit and effective to interrupt current flow through said electrical circuit upon reception of a trip signal;
conditioning means coupled to said electrical circuit to condition a current value proportionate to said current flow, said conditioning means producing a conditioned signal representative of the magnitude of said current value;
operating means effective for sampling said conditioned signal at a predetermined frequency and for deriving therefrom, at least one measurement representative of said at least one operating characteristic, said operating means further being effective for comparing, after a preselected sequence of sampling events, said at least one measurement derived from said at least one operating characteristic to a corresponding at least one preselected tripping parameter as represented by a trip curve and generating said trip signal when said at least one operating characteristic is at least equal to said corresponding at least one preselected tripping parameter, said operating means including a processor element which has a memory portion associated therewith;
display means coupled to said operating means for selectively displaying a value proportionate to said at least one operating characteristic, said display means further including indicating means for identifying said value that has been displayed;
and
wherein said at least one measurement that said operating means derives from said conditioned signal is proportionate to at least one RMS value and further wherein, at times when said at least one measurement is associated with said current flow in said electrical circuit, said at least one RMS value is at least a first and a second RMS value measured at different time durations which at least partially coincide and during said timely sampled values of said conditioned signal are summed such that, at least a first and a second summation result therefrom which can be stored in at least two separate memory locations of said memory portion of said processor element, said operating means further being effective for performing a mathematical operation on said at least said first and second summations to derive said measurements which are proportionate to said at least said first and second RMS values.

3 more elements