Method and system of calibrating sensing components in a circuit breaker system
First Claim
1. A method of calibrating variable components of 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 coupled to the controller, the method comprising:
- writing a calibration instruction routine in a first location of the memory;
injecting a test current into the circuit breaker signal chain, the test current having a test current peak;
measuring the test current peak of the test current in the circuit breaker signal chain;
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 signal chain; and
determining a calibration factor based on the comparison.
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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.
33 Citations
23 Claims
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1. A method of calibrating variable components of 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 coupled to the controller, the method comprising:
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writing a calibration instruction routine in a first location of the memory; injecting a test current into the circuit breaker signal chain, the test current having a test current peak; measuring the test current peak of the test current in the circuit breaker signal chain; 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 signal chain; and determining a calibration factor based on the comparison. - 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 microcontroller 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. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 23)
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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 computer readable medium; and a plurality of instructions wherein at least a portion of said plurality of instructions are storable in said 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; and storing data indicative of the test current peak in the memory. - View Dependent Claims (21, 22)
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Specification