General Electric Company

James J Smith

Roger N Castonguay

Thomas A Murphy

A method for configuring a digital overcurrent relay to provide a plurality of selectable time overcurrent characteristic responses corresponding to a plurality of target curves. According to one embodiment, a template curve is selected from the plurality of target curves, and a scaling factor is generated for each remaining target curve, wherein the relay comprises means for generating approximated curves from a given template curve and a given scaling factor. It is determined whether each approximated curve is within a threshold amount of total error with respect to its corresponding target curve. If any approximated curves are above the threshold amount, then a further template is selected from the plurality of target curves, and scaling factors are again generated and adjusted for the further template curve, until no approximated curves are above the threshold amount.

Matching overcurrent characteristic curves

A remote closing operator is positioned within a circuit breaker enclosure to allow remote operation of the circuit breaker operating mechanism to open and close the circuit breaker contacts. A pair of solenoids are employed to control the state of the contact closing springs. The first solenoid is energized to initially release the contact closing springs and the second solenoid is energized to interrupt the flow of current to the first solenoid.

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Avon, CT, United States of America

James J Smith