Schneider Electric USA, Inc.

Issa Vignon Dramé

Randall James Gass

Joseph R Beierschmitt

Brennan T Lentz

Method and system for performing arc fault and ground fault detection in a dual function CAFI/GFCI circuit breaker uses two analog-to-digital converters (ADC), one for performing arc fault sampling and one for performing ground fault sampling. Each ADC operates independently of the other ADC and may be accessed as needed by the microcontroller without interfering with the operation of the other ADC. Such simultaneous use of multiple ADCs minimizes or eliminates the need for complex time slicing and similar control schemes, thus freeing up the microcontroller for other operations and fault detection related tasks.

Arc fault and ground fault interrupter using dual ADC

Sampling for arc-fault detection, ground-fault detection, and grounded-neutral fault detection uses a single analog-to-digital converter (ADC). The arc-fault and ground-fault sampling occurs at regular sampling periods that are relatively short com pared to the time between them, thus allowing grounded-neutral fault sampling to occur before and/or after one of these sampling periods. A predefined event may be used to ensure the grounded-neutral fault sampling occurs immediately before and/or after one of the periodic sampling periods. The predefined event may be the expiration of a timer or the time for a sinusoidal signal in a ground fault sense circuit to make a predefined number of zero-crossings. This avoids interference between the arc-fault sampling, the ground-fault sampling and grounded-neutral fault sampling, allowing a single ADC to perform all samplings concurrently. The timing of the predefined event may be periodically reset to compensate for any changes due to temperature and/or over time.

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West Allis, WI, United States of America

Issa Vignon Dramé