# US 2014/0192451 A1 · Device and method for preventing arc flashes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192451 A1 - Document ID: US20140192451A1 - Status: Published application - Kind: A1 - Application number: 14/146,043 - Filed: 2014-01-02 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Littelfuse, Inc. - Inventors: Anthony S. Locker; Justin Mahaffey - Web page: https://patentgrep.com/patent/US20140192451A1 ## CPC - H02H 5/04: responsive to abnormal temperature {(specially adapted for electric machines H02H7/0852)} - H02H 1/0023: {sensing non electrical parameters, e.g. by optical, pneumatic, thermal or sonic sensors} - 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 device for preventing arc flashes in electrical systems is provided. The device may include at least one heat sensor for measuring a temperature of an electrical conductor, and a controller operatively coupled to the at least one heat sensor and configured to arrest current in the electrical conductor if the measured temperature exceeds a predefined threshold temperature. ## Claims ### Claim 1 An arc-flash detection device for preventing arc-flashes in an electrical system, the arc-flash detection device comprising: a heat sensor for monitoring a temperature of an electrical conductor; and a controller operably coupled to the heat sensor, the controller configured to receive an indication of the temperature of the electrical conductor from the heat sensor and arrest a flow of current in the electrical conductor based on the monitored temperature. ### Claim 2 (depends on 1) The arc-flash detection device of claim 1, further comprising a relay operably connected to the controller, the relay further operably connected to a switch disposed in line in the electrical conductor, the relay configured to receive an signal from the controller to arrest the flow of current in the electrical conductor and cause the switch to open based on the received signal. ### Claim 3 (depends on 2) The arc-flash detection device of claim 2, wherein the controller is configured to compare the temperature of the electrical conductor to a threshold temperature. ### Claim 4 (depends on 3) The arc-flash detection device of claim 3, wherein the controller is configured to: determine whether the temperature of the electrical conductor exceeds the threshold temperature; and determine the flow of current should be arrested based on the determination that the temperature of the electrical conductor exceeds the threshold temperature. ### Claim 5 (depends on 2) The arc-flash detection device of claim 2, wherein the electrical conductor is a first electrical conductor, the heat sensor further configured to monitor a temperature of a second electrical conductor and a third electrical conductor and send an indication of the temperature of first electrical conductor, the second electrical conductor, and the third electrical conductor to the controller. ### Claim 6 (depends on 5) The arc-flash detection device of claim 5, wherein the controller is configured to compare the temperature of the first electrical conductor, the temperature of the second electrical conductor, and the temperature of the third electrical conductor to a threshold temperature. ### Claim 7 (depends on 5) The arc-flash detection device of claim 5, wherein the controller is configured to compare an average of the temperatures of the first electrical conductor, the second electrical conductor, and the third electrical conductor to a threshold temperature. ### Claim 8 (depends on 5) The arc-flash detection device of claim 5, wherein the first conductor, the second conductor, and the third conductor are electrical conductors in a three-phase power system. ### Claim 9 (depends on 1) The arc-flash detection device of claim 1, wherein the heat sensor is a first heat sensor for monitoring the temperature of a first portion of the electrical conductor, the arc-flash detection device further comprising a second heat sensor for monitoring the temperature of a second portion of the electrical conductor. ### Claim 10 (depends on 9) The arc-flash detection device of claim 9, wherein the first and second heat sensors are wirelessly coupled to the controller. ### Claim 11 An electrical system configured to prevent arc-flashes comprising: a first electrical conductor, a second electrical conductor, and a third electrical conductor for distributing power from a power source to a load; and an arc-flash detection device comprising: a heat sensor for monitoring a temperature of the first electrical conductor, the second electrical conductor, and the third electrical conductor; and a controller operably coupled to the heat sensor, the controller configured to receive an indication of the temperature of the first electrical conductor, the second electrical conductor, and the third electrical conductor from the heat sensor and arrest a flow of current in the electrical conductor based on the monitored temperature. ### Claim 12 (depends on 11) The electrical system of claim 11, the arc-flash detection device further comprising a relay operably connected to the controller, the relay further operably connected to at least one switch disposed inline in the first, the second, and the third electrical conductor, the relay configured to receive an indication from the controller to arrest the flow of current in the first, the second, and the third electrical conductor and cause the switch to open based on the monitored temperature. ### Claim 13 (depends on 12) The electrical system of claim 12, wherein the controller is configured to compare the temperature of the first electrical conductor, the second electrical conductor and the third electrical conductor to a threshold temperature and determine the flow of current should be arrested based on the comparison. ### Claim 14 (depends on 13) The electrical system of claim 13, wherein the controller is configured to: determine whether the temperature of the first, the second, and the third electrical conductor exceeds the threshold temperature; and determine the flow of current should be arrested based on the determination that the temperature of the first, the second, and the third electrical conductor exceeds the threshold temperature. ### Claim 15 (depends on 11) The electrical system of claim 11, wherein the first conductor, the second conductor, and the third conductor are electrical conductors in a three-phase power system. ### Claim 16 (depends on 11) The electrical system of claim 11, wherein the heat sensor is a first heat sensor for monitoring the temperature of a first portion of the first, the second, and the third electrical conductors, the arc-flash detection device further comprising a second heat sensor for monitoring the temperature of a second portion of the first, the second, and the third electrical conductors. ### Claim 17 A method for preventing arc-flashes in electrical systems comprising: measuring a temperature of an electrical conductor; determining whether the measured temperature exceeds a predetermined threshold; and arresting current in the electrical conductor based on the determination that the measured temperature exceeds a predetermined threshold. ### Claim 18 (depends on 17) The method of claim 17, wherein measured the temperature of the electrical conductor comprises receiving a signal from a heat sensor, the signal corresponding to the temperature of the electrical conductor. ### Claim 19 (depends on 18) The method of claim 18, wherein the electrical conductor is a first electrical conductor, the method further comprising measuring the temperature of a second electrical conductor and a third electrical conductor. ### Claim 20 (depends on 17) The method of claim 17, wherein measuring the temperature of the electrical conductor comprises: receiving a first signal from a first heat sensor, the first signal corresponding to the temperature of a first portion of the electrical conductor; and receiving a second signal from a second heat sensor, the second signal corresponding to the temperature of a second portion of the electrical conductor.