Patent ID: 8014115

Claim:
A method of operating a circuit breaker system comprising: defining a first user defined trip curve for a first circuit breaker, said first trip curve having an unrestrained short time threshold, an unrestrained I 2 t region having a slope, a time delay region, and an unrestrained instantaneous threshold; defining a second user defined trip curve for said first circuit breaker, said second trip curve having a restrained instantaneous threshold and a restrained I 2 t region having a slope, and a time delay, said second user defined trip curve being noncontiguous with and non-overlapping with said first user defined trip curve, wherein the second user defined trip curve has at least one of said restrained instantaneous threshold or said I 2 t region at higher operating level than said first user defined trip curve unrestrained instantaneous threshold or said unrestrained I 2 t region; creating a third user defined trip curve for a second circuit breaker wherein said second circuit breaker is coupled to receive electrical power from said first circuit breaker, said third trip curve having an I 2 t region having a slope, a time delay region and an instantaneous threshold, wherein said third user defined trip curve is non-overlapping with said second user defined trip curve; modifying said second user defined trip curve restrained instantaneous threshold and said slope of said second user defined second trip curve restrained I 2 t region, wherein said modified slope of said second trip curve restrained I 2 t region and said restrained instantaneous threshold are at a higher operating level than said third trip curve I 2 t region and said third trip curve instantaneous threshold; receiving an interlock signal at said first circuit breaker from said second circuit breaker; and, changing a trip response of said first circuit breaker from said first trip curve to said second trip curve in response to receiving said interlock signal.