# US 9,520,742 B2 · Monitoring system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,742 B2 - Document ID: US9520742B2 - Status: Granted - Kind: B2 - Application number: 14/323,659 - Filed: 2014-07-03 - Published: 2016-01-07 - Granted: 2016-12-13 - Earliest claimed: 2014-07-03 - Assignees: Hubbell Incorporated - Applicants: Hubbell Incorporated - Inventors: Philip Gregory Brown; Alec M. Mercer; Jeff T. Reid - Web page: https://patentgrep.com/patent/US9520742B2 ## CPC - H02J 9/00: Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting - H05B 47/22: {with communication between the lamps and a central unit} - G08B 29/10: Monitoring of the annunciator circuits - H05B 47/18: via data-bus transmission - H05B 47/185: via power line carrier transmission - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS ## Abstract System and method for monitoring electrical devices such as luminaires, including ballast and/or battery powered lighting components, for variety of fault conditions from central location utilize monitoring unit that interfaces with host lighting fixture or luminaire to allow status of host to be remotely monitored. Monitoring unit can interface with host in fully galvanically isolated manner using current transformers allowing host lighting fixture to be monitored in the least intrusive manner. Monitoring unit can be seamlessly fitted to new luminaires or existing luminaires. Current transformer interface has minimal effect on host ballast functionality and operation. Monitoring system may include a plurality of monitoring units multi-dropped on a single field bus network or in a power line communication. Power for monitoring unit can be derived from field bus network or power line. Operating parameters and addressing information of monitoring unit may be configured via interface using laptop or PC. ## Claims ### Claim 1 A lighting fixture monitoring unit comprising: a housing; a sensor configured within said housing in a galvanically isolated communication with at least a portion of a wiring of a lighting fixture, said portion of the wiring disposed outside of the housing; and a microprocessor receiving output information from the sensor and outputting monitoring data indicative of a status of the lighting fixture, wherein said output information received from the sensor is based at least on said galvanically isolated communication with said portion of said wiring disposed outside of the housing. ### Claim 2 (depends on 1) The lighting fixture monitoring unit of claims 1, wherein the lighting fixture comprises a ballast and a light source, the wiring comprises ballast wiring, and the status comprises at least one of mains light source on status, inhibit input status, emergency light source current, and a battery charge current. ### Claim 3 (depends on 1) The lighting fixture monitoring unit of claims 1, wherein the microprocessor outputs the monitoring data to a central monitor via one of a field bus network or a power line communication. ### Claim 4 (depends on 1) The lighting fixture monitoring unit of claims 1, wherein the microprocessor outputs the monitoring data to a central monitor via a wireless communication. ### Claim 5 (depends on 4) The lighting fixture monitoring unit of claims 4, wherein the microprocessor outputs the monitoring data to the central monitor via at least one of a wireless mesh network, a web-based communication, a blue tooth, and a short-range or long-range radio frequency (RF) communication. ### Claim 6 (depends on 3) The lighting fixture monitoring unit of claim 3, wherein the microprocessor derives power from one of the field bus network or the power line. ### Claim 7 (depends on 1) The lighting fixture monitoring unit of claim 1, further comprising an interface, wherein operating parameters and addressing information enabling communication with the microprocessor are configured via the interface. ### Claim 8 (depends on 1) The lighting fixture monitoring unit of claim 1, wherein the housing comprises: an interior compartment having the microprocessor and sensor disposed therein, and an essentially cylindrical hollow tube projecting through the compartment, the tube having a first surface within the interior of the compartment, and a second surface exterior to the housing diametrically opposed to the first surface, and defining a portion of an external surface of the compartment, the sensor including a current transformer having an essentially toroidal inductor disposed concentrically with respect to the first surface of the tube, wherein the wiring of the lighting fixture passes through the tube within the second surface exterior to the housing. ### Claim 9 (depends on 2) The lighting fixture monitoring unit of claim 2, wherein the wiring comprises return cables for at least one of the light source, a battery cable and an indicator cable of the ballast. ### Claim 10 (depends on 8) The lighting fixture monitoring unit of claim 8, wherein the housing further includes an elevated portion and the tube is disposed horizontally through the elevated portion of the housing, whereby the wiring of the fixture is fed through and exterior to the housing via the tube. ### Claim 11 (depends on 1) The lighting fixture monitoring unit of claim 1, wherein the output information from the sensor comprises a sensed AC current signal of the wiring in communication with the sensor, the sensed AC current is converted into a DC voltage for analogue to digital signal conversion and averaging process by the microprocessor, and the monitoring data indicative of the status output by the microprocessor is derived from the averaging. ### Claim 12 (depends on 11) The lighting fixture monitoring unit of claim 11, wherein the averaging process comprises acquiring samples of the signal at a sampling rate, summing the samples, and yielding the average value from the summing, and the status output by the microprocessor is based on the average value. ### Claim 13 A lighting system comprising: a light source; a ballast connected to AC mains and providing power to the light source; a wiring electrically interconnecting the light source, the ballast and the AC mains; a field bus; and a monitoring unit comprising a housing, an electrical connection to the field bus, and an interface with at least one of the light source and the ballast, wherein the monitoring unit is powered by the filed bus via the electrical connection, and detects a status of the at least one of the light source and the ballast via the interface, the interface including a galvanically isolated connection of a sensor configured within said housing with at least a portion of the wiring disposed outside of the housing of the monitoring unit, and the detected status is based at least on said galvanically isolated connection with said portion of the wiring disposed outside of the housing of the monitoring unit. ### Claim 14 (depends on 13) The lighting system of claim 13, wherein the monitoring unit outputs information indicative of the status via the field bus. ### Claim 15 (depends on 13) The lighting system of claim 13, wherein the monitoring unit further includes a transceiver for outputting information indicative of the status via at least one of a wired or wireless communication. ### Claim 16 A lighting system comprising: a plurality of light sources; a plurality of ballast connected to AC mains and providing power to the respective light sources; a plurality of wirings electrically interconnecting each of the light sources and respective ballasts, and the AC mains; a field bus; and a plurality of monitoring units each comprising a housing, an electrical connection to the field bus, and an interface with the respective at least one of light sources and the ballasts, wherein each of the monitoring units is powered by the filed bus via the electrical connection, and detects a status of the respective at least one of the light sources and the ballasts via the interface, the interface including a galvanically isolated connection of a sensor configured within said housing with at least a portion of the wirings interconnecting the respective at least one of the light sources and the ballasts, and the AC mains, said portion of the wirings disposed outside of the housing of the respective monitoring unit, and the detected status is based at least on said galvanically isolated connection with said portion of the wirings disposed outside of the housing of the respective monitoring unit. ### Claim 17 (depends on 16) The lighting system of claim 16, wherein each of the monitoring units outputs information indicative of the status via the field bus. ### Claim 18 (depends on 16) The lighting system of claim 16, wherein at least one of the monitoring units further includes a transceiver for outputting information indicative of the status via at least one of a wired or wireless communication. ### Claim 19 (depends on 16) The lighting system of claim 16, wherein each of at least two of the plurality of the monitoring units further includes a wireless transceiver for outputting information indicative of the status via a wireless communication. ### Claim 20 (depends on 19) The lighting system of claim 19, wherein the wireless communication includes at least one of a wireless mesh network, a web-based communication, a blue tooth, and a short-range or long-range radio frequency (RF) communication. ### Claim 21 (depends on 19) The lighting system of claim 19, wherein the monitoring units including the wireless transceiver for outputting information indicative of the status are configured for communication in a wireless self-healing mesh network. ### Claim 22 A lighting system comprising: a light source; a ballast connected to AC mains and providing power to the light source; a wiring electrically interconnecting the light source, the ballast and the AC mains; a power line communication master; and a monitoring unit comprising a housing, an electrical connection to the power line, and an interface with at least one of the light source and the ballast, wherein the monitoring unit detects a status of the at least one of the light source and the ballast via the interface, the interface including a sensor configured within said housing in a galvanically isolated connection with at least a portion of the wiring disposed outside of the housing of the monitoring unit, and the detected status is based at least on said galvanically isolated connection with said portion of the wiring disposed outside of the housing of the monitoring unit, and the monitoring unit communicates the detected status to the power line communication master in response to a polling request from the power line communication master. ### Claim 23 (depends on 22) The lighting system of claim 22, wherein the monitoring unit further comprising an interface, wherein operating parameters and addressing information enabling communication with the monitoring unit are configured via the interface. ### Claim 24 (depends on 23) The lighting system of claim 23, further comprising a user interface in wired or wireless communication with the power line communication master, wherein the user interface selectively outputs information indicative of the status detected by the monitoring unit transmitted to the power line communication master in reply to the polling request. ### Claim 25 (depends on 24) The lighting system of claim 24, wherein the polling request results in continuous detecting of the status by the monitoring unit. ### Claim 26 (depends on 24) The lighting system of claim 24, wherein the polling request is selectively generated based on input via the user interface. ### Claim 27 (depends on 22) The lighting system of claim 22, wherein the monitoring unit includes a controller and a control circuit for selectively controlling operation of the light source. ### Claim 28 (depends on 22) The lighting system of claim 22, wherein the controller includes a microprocessor and a non-transient computer readable storage medium, and the microprocessor is programmable to control the operation of the light source based on at least one of control commands received from the power line communication master, and the status detected by the monitoring unit. ### Claim 29 A monitoring method comprising: disposing a monitoring unit with respect to a wiring of an electrically powered device, said monitoring unit comprising a housing and a sensor configured within said housing of the monitoring unit; sensing an AC current signal of said wiring of the electrically powered device via a galvanically isolated communication of said sensor with at least a portion of the wiring of the electrically powered device, said portion of the wiring disposed outside of the housing of the monitoring unit; converting the sensed AC current into a DC voltage for analogue to digital signal conversion and averaging processing, and deriving from the averaging processing monitoring data indicative of a status of the electrically powered device; and outputting the monitoring data indicative of the status of the electrically powered device. ### Claim 30 (depends on 29) The monitoring method of claim 29, wherein the averaging processing comprises acquiring samples of the signal at a sampling rate, summing the samples, and yielding the average value from the summing, and the monitoring data is based on the average value.