Electronic trip unit with user-adjustable sensitivity to current spikes
AssigneeGeneral Electric Company
InventorsAlan Joseph Messerli, Mark Frederick Culler
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Abstract
An electronic trip unit and a method of protection in an electronic trip unit comprises selecting a limit value, sensing an electrical signal to provide corresponding first and second sensed signals, each indicative of an electrical characteristic of the electrical signal, comparing said first and second sensed signal to determine a rate of rise of said electrical characteristic, comparing said rate of rise to said limit value to detect a spike in said electrical characteristic, and withholding generation of a trip signal when said rate of rise is greater than said limit value.
Claims18
A method of protection in an electronic trip unit, comprising:
- selecting a limit value;
- sensing an electrical signal to provide corresponding first and second sensed signals, each indicative of an electrical characteristic of the electrical signal;
- comparing said first and second sensed signal to determine a rate of rise of said electrical characteristic;
- comparing said rate of rise to said limit value to detect a spike in said electrical characteristic;
- and
- withholding generation of a trip signal when said rate of rise is greater than said limit value.
An electronic trip unit comprising:
- a switch for selecting a limit value;
- a sensor for sensing an electrical signal to provide first and second sensed signals, each indicative of an electrical characteristic of the electrical signal;
- and
- a signal processor responsive to said sensed signals, and having memory for storing signals including program signals defining an executable program for,
- comparing said first and second sensed signals to determine a rate of rise of said electrical characteristic,
- comparing said rate of rise to said limit value to detect a spike in said electrical characteristic, and
- withholding generation of a trip signal when said rate of rise is greater than said limit value.
Dependencies are inferred from the claim text.