# US 12,191,100 B2 · Arc flash detection method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,100 B2 - Document ID: US12191100B2 - Status: Granted - Kind: B2 - Application number: 17/559,769 - Filed: 2021-12-22 - Published: 2023-06-22 - Granted: 2025-01-07 - Earliest claimed: 2021-12-22 - Assignees: Schneider Electric USA, Inc. - Applicants: Schneider Electric USA, Inc. - Inventors: John J. Shea - Web page: https://patentgrep.com/patent/US12191100B2 ## CPC - H01H 83/20: operated by excess current as well as by some other abnormal electrical condition - G01R 31/1227: {of components, parts or materials (G01R31/1209, G01R31/1218, G01R31/18 take precedence; circuits therefor G01R31/14; testing vessels of electrodes G01R31/16)} - G01R 31/3272: {Apparatus, systems or circuits therefor (G01R31/3275 takes precedence)} - G01R 31/52: Testing for short-circuits, leakage current or ground faults - H02H 1/0015: {Using arc detectors} - H02H 3/10: additionally responsive to some other abnormal electrical conditions - H02H 3/445: {of DC quantities} - H02H 7/262: {involving transmissions of switching or blocking orders} - H01H 2083/201: {the other abnormal electrical condition being an arc fault} - H02H 1/0023: {sensing non electrical parameters, e.g. by optical, pneumatic, thermal or sonic sensors} - H02H 3/04: with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned {(watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18)} - H02H 3/20: responsive to excess voltage - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H) ## Abstract A method and system are provided to control circuit breaker operations. In the method and system, near-field RF signal is monitored at or around electrical contacts of the circuit breaker using at least one near-field radio frequency (RF) sensor, and far-field RF signal away from the contacts of the circuit breaker are monitored using at least one far-field RF sensor. A rate of change of current over time is also monitored on the circuit using at least one sensor. An arc fault on the circuit is detected based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current. A tripping operation is implemented on the circuit breaker to disconnect the power supply from the circuit, in response to the detection of the arc fault. ## Claims ### Claim 1 A method of controlling operations of a circuit breaker for connecting or disconnecting a power supply to or from a circuit respectively, the method comprising: monitoring, using at least one near-field radio frequency (RF) sensor of the circuit breaker, near-field RF signal at or around electrical contacts of the circuit breaker; monitoring, using at least one far-field RF sensor of the circuit breaker, far-field RF signal away from the contacts of the circuit breaker; monitoring, using at least one sensor of the circuit breaker, a rate of change of current over time on the circuit; detecting an arc fault on the circuit based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current; and implementing a tripping operation on the circuit breaker to disconnect the power supply from the circuit, in response to the detection of the arc fault. ### Claim 2 (depends on 1) The method according to claim 1, wherein the at least one near-field sensor comprises a near-field RF sensor for each pole of the circuit breaker which comprises a multi-pole circuit breaker or a circuit breaker for a multi-phase power supply. ### Claim 3 (depends on 1) The method according to claim 1, wherein the controlling initiates a tripping operation in response to (1) detection of high initial RF signal pulse and a sustained low level RF signal via the far-field RF sensor, (2) no detection of an RF signal via the near-field RF sensor, and (3) detection of the rate of change of current over time satisfying or exceeding a trip threshold. ### Claim 4 (depends on 1) The method according to claim 1, wherein the circuit breaker comprises an upstream circuit breaker, and the circuit comprises at least one branch circuit having a branch circuit breaker which is downstream from the upstream circuit breaker, the method further comprising: receiving information that the at least one branch circuit breaker is tripping or switching; and inhibiting the tripping operation of the upstream circuit breaker in response to the received information. ### Claim 5 (depends on 1) The method according to claim 1, wherein the circuit breaker comprises an upstream or feeder circuit breaker, and the circuit comprises a plurality of branch circuits each of which has a branch circuit breaker which is downstream from the upstream or feeder circuit breaker, the method further comprising: receiving information that one or more of the plurality of branch circuit breakers are tripping or switching; and inhibiting the tripping operation of the upstream or feeder circuit breaker in response to the received information. ### Claim 6 (depends on 1) The method according to claim 1, wherein the near-field and far-field RF sensors are tuned for a frequency range comprising at or around 10 to 30 MHz bandwidth. ### Claim 7 (depends on 1) The method according to claim 1, wherein the monitored near-field and far-field RF signals are used to monitor electrical conditions on the circuit within a switchgear enclosure. ### Claim 8 (depends on 1) The method according to claim 1, wherein the implementing implements the tripping operation, which comprises a fast trip operation of the circuit breaker, by directly tripping a breaker mechanism of the circuit breaker, via a fast trip solenoid, in response to detection of the arc fault. ### Claim 9 (depends on 8) The method according to claim 8, further comprising: receiving an inhibit signal from at least one downstream or nearby circuit breaker indicating that the downstream circuit breaker is tripping or switching; and inhibiting the fast trip operation of the circuit breaker while enabling the circuit breaker to operate in a normal trip operation mode according to at least one predefined trip curve. ### Claim 10 A circuit breaker for connecting or disconnecting a power supply to or from a circuit respectively, comprising: at least one near-field radio frequency (RF) sensor for monitoring near-field RF signal at or around electrical contacts of the circuit breaker; at least one far-field radio frequency (RF) sensor for monitoring far-field RF signal away from the contacts of the circuit breaker; at least one sensor for monitoring a rate of change of current over time on the circuit; at least one processor configured: to detect an arc fault on the circuit based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current; and to initiate implementation of a tripping operation to disconnect the power supply from the circuit, in response to the detection of the arc fault. ### Claim 11 (depends on 10) The circuit breaker according to claim 10, wherein the at least one near-field sensor comprises a near-field RF sensor for each pole of the circuit breaker which comprises a multi-pole circuit breaker or a circuit breaker for a multi-phase power supply. ### Claim 12 (depends on 1) The circuit breaker according to claim 1, wherein the at least one processor initiates implementation of a tripping operation in response to (1) detection of high initial RF signal pulse and a sustained low level RF signal via the far-field RF sensor, (2) no detection of an RF signal via the near-field RF sensor, and (3) detection of the rate of change of current over time satisfying or exceeding a trip threshold. ### Claim 13 (depends on 10) The circuit breaker according to claim 10, wherein the circuit breaker comprises an upstream circuit breaker, and the circuit comprises at least one branch circuit having a branch circuit breaker which is downstream from the upstream circuit breaker, the at least one processor being further configured: to receive information that the at least one branch circuit breaker is tripping or switching; and to inhibit the tripping operation of the upstream circuit breaker in response to the received information. ### Claim 14 (depends on 10) The circuit breaker according to claim 10, wherein the circuit breaker comprises an upstream or feeder circuit breaker, and the circuit comprises a plurality of branch circuits each of which has a branch circuit breaker which is downstream from the upstream or feeder circuit breaker, the at least one processor being further configured: to receive information that one or more of the plurality of branch circuit breakers are tripping or switching; and to inhibit the tripping operation of the upstream or feeder circuit breaker in response to the received information. ### Claim 15 (depends on 10) The circuit breaker according to claim 10, wherein the near-field and far-field RF sensors are tuned for a frequency range comprising at or around 10 to 30 MHz bandwidth. ### Claim 16 (depends on 10) The circuit breaker according to claim 10, wherein the monitored near-field and far-field RF signals are used to monitor electrical conditions on the circuit within a switchgear enclosure. ### Claim 17 (depends on 10) The circuit breaker according to claim 10, wherein the at least one processor is configured to implement the tripping operation, which comprises a fast trip operation of the circuit breaker, by directly tripping a breaker mechanism of the circuit breaker, via a fast trip solenoid, in response to detection of the arc fault. ### Claim 18 (depends on 17) The circuit breaker according to claim 17, wherein the at least one processor is further configured: to receive an inhibit signal from at least one downstream or nearby circuit breaker indicating that the downstream circuit breaker is tripping or switching; and to inhibit the fast trip operation of the circuit breaker while enabling the circuit breaker to operate in a normal trip operation mode according to at least one predefined trip curve. ### Claim 19 A non-tangible computer readable medium storing computer code, which when executed by at least one processor, implements a process of controlling operations of a circuit breaker, the process comprising: monitoring, using at least one near-field radio frequency (RF) sensor of the circuit breaker, near-field RF signal at or around electrical contacts of the circuit breaker; monitoring, using at least one far-field RF sensor of the circuit breaker, far-field RF signal away from the contacts of the circuit breaker; monitoring, using at least one sensor of the circuit breaker, a rate of change of current over time on the circuit; detecting an arc fault on a circuit based on the monitored near-field RF signal, the monitored far-field RF signal, and the monitored rate of change of current; and implementing a tripping operation on the circuit breaker to disconnect a power supply from the circuit, in response to the detection of the arc fault.