Method and system of calibrating sensing components in a circuit breaker system
First Claim
1. A method of calibrating a circuit breaker having a signal chain including a current transformer, a burden resistor, a stored energy circuit, and a controller, the circuit breaker including a memory coupled to the controller, the method comprising:
- writing a calibration instruction routine in a first location of the memory;
connecting a current injector to the current transformer;
injecting a test current into the circuit breaker signal chain at a high temperature by the test current injector, the test current having a test current peak;
measuring the test current peak of the test current in the circuit breaker signal chain via the controller;
storing test current peak data indicative of the test current peak in a second location of the memory;
reading the test current peak data from the second location of the memory via a communications interface;
comparing the test current peak data with nominal current data related to the test current;
determining a calibration factor based on the comparison;
creating, by the controller, a specialized calibration table based on the calibration factor and a nominal template modeled from the current transformer; and
writing the specialized calibration table to the second location of the memory.
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Accused Products
Abstract
A method and system to calibrate a motor circuit protection device is disclosed. An example method calibrates a signal chain of a circuit breaker. The signal chain includes a current transformer, a burden resistor, a stored energy circuit and a controller. The circuit breaker includes a memory coupled to the controller. A calibration instruction routine is written in a first location of the memory. A test current is injected in the circuit breaker signal chain. The test current peak of the test current in the circuit breaker signal chain is measured. Data indicative of the test current peak is stored in a second location of the memory. The test current peak data is read from the second location of the memory. The test current peak data is compared with nominal current data related to the signal chain remotely from the circuit breaker. A calibration factor is determined based on the comparison.
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Citations
22 Claims
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1. A method of calibrating a circuit breaker having a signal chain including a current transformer, a burden resistor, a stored energy circuit, and a controller, the circuit breaker including a memory coupled to the controller, the method comprising:
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writing a calibration instruction routine in a first location of the memory; connecting a current injector to the current transformer; injecting a test current into the circuit breaker signal chain at a high temperature by the test current injector, the test current having a test current peak; measuring the test current peak of the test current in the circuit breaker signal chain via the controller; storing test current peak data indicative of the test current peak in a second location of the memory; reading the test current peak data from the second location of the memory via a communications interface; comparing the test current peak data with nominal current data related to the test current; determining a calibration factor based on the comparison; creating, by the controller, a specialized calibration table based on the calibration factor and a nominal template modeled from the current transformer; and writing the specialized calibration table to the second location of the memory. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A testing system to calibrate a circuit breaker for detecting a current range, the circuit breaker including a current transformer, a burden resistor, a stored energy circuit, a controller, a first memory location and a second memory location, the memory locations coupled to the controller, the testing system comprising:
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a set of calibration instructions stored in the first memory location; a test current injector connectable to the current transformer, the test current injector injecting a test current to the current transformer at a high temperature, wherein the calibration instruction set causes the controller to measure the peak test current injected and write a peak current value to the second memory location; a data communications interface in communication with the second memory location to read the peak current values; and a test instruction set to calculate a calibration factor based on a comparison of the peak current value with data relating to the test current, wherein the test instruction set creates a specialized calibration table based on the calibration factor and a nominal template modeled from the current transformer; and
wherein the test instruction set causes the data communications interface to write the specialized calibration table to the second memory location. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
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20. An article of manufacture for calibrating a signal chain of a circuit breaker, the signal chain including a current transformer, a burden resistor, a stored energy circuit and a controller, the circuit breaker including a memory accessible to the controller, the article of manufacture comprising:
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a non-transitory computer readable medium; and a plurality of instructions wherein at least a portion of said plurality of instructions are storable in said non-transitory computer readable medium, and further wherein said plurality of instructions are configured to cause the controller to perform; measuring at a high temperature a test current peak of a test current injected in the circuit breaker signal chain; storing data indicative of the test current peak in the memory; calculating a calibration factor based on a comparison of the data indicative of the test current peak with data relating to the test current; creating a specialized calibration table based on the calibration factor and a nominal template modeled from the current transformer; and storing the specialized calibration table. - View Dependent Claims (21, 22)
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Specification