Granted Patent B2

US 12,562,563 · App. 18/753,456 · Granted Feb 24, 2026

Inventors: John E. Brower (Fairfield, CT); James Casey Musson (Derby, CT); William Vernon Miller, III (Aldie, VA); Joseph Michael Meady (Stratford, CT); Joseph Edgar Dupuis (Griswold, CT); Brian S. Chia (Cheshire, CT)

Assignee: Hubbell Incorporated

H02H3/16H02H1/0007

Abstract

Claims (43)

1 . A circuit interrupting device comprising:

a phase conductor;

a neutral conductor;

an interrupter configured to disconnect the phase conductor and the neutral conductor from a load;

a sensor configured to generate a first signal indicative of current flowing through at least one selected from a group consisting of the phase conductor and the neutral conductor; and

a microcontroller electrically connected to the sensor and the interrupter, the microcontroller including an electronic processor configured to:

receive the first signal from the sensor,

compensate the first signal with respect to a temperature of the microcontroller,

determine whether a difference between the first signal and a reference signal exceeds a threshold, and

activate the interrupter when the difference exceeds the threshold.

2 . The circuit interrupting device of claim 1 , wherein the sensor is a transformer that includes an aperture through which the phase conductor and the neutral conductor pass through; and

wherein the first signal is generated in a first conductor that is wound around the transformer and electrically connected to the microcontroller.

3 . The circuit interrupting device of claim 2 , wherein the circuit interrupting device further includes a second transformer that includes a second aperture through which the phase conductor and the neutral conductor pass through; and wherein a second conductor is wound around the second transformer and electrically connected to the microcontroller.

4 . The circuit interrupting device of claim 3 , wherein the microcontroller is further configured to:

apply a test signal to the second conductor;

receive a second signal indicative of a current flowing through the phase conductor and the neutral conductor from the sensor;

determine whether a difference between the second signal and the reference signal exceeds the threshold after applying the test signal to the second conductor; and

activate the interrupter when the difference between the second signal and the reference signal exceeds the threshold.

5 . The circuit interrupting device of claim 4 , wherein the microcontroller is further configured to apply the test signal to the second conductor based on one selected from a group consisting of a phase of a power signal applied to the phase and neutral conductors, a quadrant of the power signal applied to the phase and neutral conductors, a wave shape of the power signal applied to the phase and neutral conductors, a temperature, and a power factor.

6 . The circuit interrupting device of claim 4 , further comprising a wireless communication circuit electrically connected to the microcontroller; and

wherein the microcontroller is further configured to transmit, by the wireless communication circuit, a signal indicative of an occurrence of a grounded neutral condition to an external device when the difference between the second signal and the reference signal exceeds the threshold.

7 . The circuit interrupting device of claim 1 , wherein the microcontroller is further configured to determine a frequency of a voltage applied to the phase conductor and neutral conductor based on a zero-cross detection signal; and

wherein the microcontroller is further configured to perform a ground fault self-test after the frequency is determined.

8 . The circuit interrupting device of claim 1 , further comprising a wireless communication circuit electrically connected to the microcontroller; and

wherein the microcontroller is further configured to transmit, by the wireless communication circuit, a signal indicative of an occurrence of a ground fault to an external device when the difference exceeds the threshold and the microcontroller has not performed a ground fault self-test.

9 . The circuit interrupting device of claim 1 , further comprising a printed circuit board (PCB);

wherein the microcontroller is electrically connected to the PCB; and

wherein the microcontroller, the phase conductor, the neutral conductor, the sensor, and the interrupter are physically supported by the PCB.

10 . A method of operating a circuit interrupting device that includes a phase conductor, a neutral conductor, an interrupter configured to disconnect the phase conductor and the neutral conductor from a load, a sensor configured to generate a signal indicative of current flowing through the phase conductor and the neutral conductor, and a microcontroller electrically connected to the sensor and the interrupter, the microcontroller including an electronic processor, the method comprising:

receiving, by the microcontroller, a first signal indicative of the current flowing through at least one selected from a group consisting of the phase conductor and the neutral conductor from the sensor;

sensing, by a temperature sensor included in the circuit interrupting device, a temperature of the microcontroller;

compensating, by the microcontroller, the signal with respect to the temperature of the microcontroller;

determining, by the microcontroller, whether a difference between the first signal and a reference signal exceeds a threshold; and

activating, by the microcontroller, the interrupter when the difference exceeds the threshold.

11 . The method of claim 10 , wherein the sensor is a transformer that includes an aperture through which the phase conductor and the neutral conductor pass through; and

wherein the signal is induced on a first conductor that is wound around the transformer and electrically connected to the microcontroller.

12 . The method of claim 11 , wherein the circuit interrupting device further includes a second transformer that includes a second aperture through which the phase conductor and the neutral conductor pass through; and

wherein a second conductor is wound around the second transformer and electrically connected to the microcontroller.

13 . The method of claim 12 , further comprising:

applying, by the microcontroller, a test signal to the second conductor;

receiving, by the microcontroller, a second signal indicative of current flowing through the phase conductor and the neutral conductor from the sensor;

determining, by the microcontroller, whether a difference between the second signal and the reference signal exceeds the threshold after applying the test signal to the second conductor; and

activating, by the microcontroller, the interrupter when the difference between the second signal and the reference signal exceeds the threshold.

Assignments (1)

Continuity (3)

References Cited (19)