# US 12,191,793 B2 · Airflow health predictive maintenance for motor drives > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,793 B2 - Document ID: US12191793B2 - Status: Granted - Kind: B2 - Application number: 17/954,064 - Filed: 2022-09-27 - Published: 2024-03-28 - Granted: 2025-01-07 - Earliest claimed: 2022-09-27 - Assignees: Rockwell Automation Technologies, Inc. - Applicants: Rockwell Automation Technologies, Inc. - Inventors: John David Allan; Tahsina Hossain; Garron K. Morris - Web page: https://patentgrep.com/patent/US12191793B2 ## CPC - H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence) - H02P 31/00: Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00 - B01D 46/0086: {Filter condition indicators} - B01D 46/446: {by pressure measuring} - B01D 46/46: automatic - H02K 9/26: Structural association of machines with devices for cleaning or drying cooling medium, e.g. with filters - H02P 29/024: Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load - H05K 7/20181: {Filters; Louvers} - H05K 7/20909: {Forced ventilation, e.g. on heat dissipaters coupled to components} - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract An airflow health predictive maintenance system and method for a motor drive includes a differential pressure sensor that senses an air pressure differential between a sensing location within an enclosed cabinet space of the motor drive and a reference location. The system includes an electronic control system configured to select a setpoint that indicates that airflow through the cabinet space has reached a value associated with a need for air filter maintenance. The control system is further configured to obtain air pressure differential measurements periodically from the differential pressure sensor and generate an actual trend comprising a series of values, wherein each of the values of the actual trend is derived from one or more of the air pressure differential measurements. The control system is also configured to project the actual trend to derive a projected trend based upon the series of values of the actual trend and compare the projected trend to the setpoint to predict an end of life event that can be used to determine a time when air filter maintenance is predicted to be required, wherein the end of life event is based upon a predicted intersection of projected trend with the setpoint. ## Claims ### Claim 1 An airflow health predictive maintenance system for a motor drive, said system comprising: a differential pressure sensor that senses an air pressure differential between a sensing location within an enclosed cabinet space of the motor drive and a reference location external to the enclosed cabinet space, wherein the air pressure differential represents a vacuum pressure established within the enclosed cabinet space; an electronic control system configured to: select a setpoint that indicates that airflow through the enclosed cabinet space has reached a value associated with a need to perform maintenance on an air filter configured to filter air flowing into the enclosed cabinet space; obtain air pressure differential measurements periodically from said differential pressure sensor and generate an actual trend comprising a series of values, wherein each of said values of said actual trend is derived from one or more of said air pressure differential measurements; project said actual trend to derive a projected trend based upon said series of values of said actual trend; and compare said projected trend to said setpoint to predict an end of life event used to determine a time when air filter maintenance is predicted to be required, wherein said end of life event is based upon a predicted intersection of said projected trend with said setpoint. ### Claim 2 (depends on 1) The airflow health predictive maintenance system as set forth in claim 1, wherein said system comprises at least one fan for inducing said airflow. ### Claim 3 (depends on 2) The airflow health predictive maintenance system as set forth in claim 2, wherein: said setpoint comprises an air pressure differential setpoint defined in terms of magnitude of air pressure differential between the enclosed cabinet space and the reference location; and said actual trend comprises an actual air pressure differential trend for which said series of values comprise a series of air pressure differential values derived from said air pressure differential measurements. ### Claim 4 (depends on 3) The airflow health predictive maintenance system as set forth in claim 3, wherein said electronic control system is further configured to output a warning related to said end of life event to at least one of: (i) a human machine interface; and (ii) a network interface. ### Claim 5 (depends on 4) The airflow health predictive maintenance system as set forth in claim 4, wherein said electronic control system is further configured to adjust the air pressure differential setpoint based upon at least one of: (i) operational loading associated with the motor drive; (ii) temperature of an ambient atmosphere surrounding the motor drive; (iii) air quality in terms of concentration of particulates or other contaminants of the ambient atmosphere; and (iv) altitude of the motor drive. ### Claim 6 (depends on 1) The airflow health predictive maintenance system as set forth in claim 1, further comprising an absolute pressure sensor for sensing an atmospheric pressure of an ambient atmosphere surrounding the motor drive. ### Claim 7 (depends on 1) The airflow health predictive maintenance system as set forth in claim 1, further comprising: at least one fan that induces said airflow through the enclosed cabinet space by moving air from a fan inlet of said at least one fan to a fan outlet of said at least one fan, wherein said sensing location and said reference location are located on opposite sides of said at least one fan adjacent said fan inlet and said fan outlet, respectively, such that said air pressure differential measurements are taken across the at least one fan. ### Claim 8 (depends on 7) The airflow health predictive maintenance system as set forth in claim 7, wherein: said setpoint comprises an airflow volume setpoint defined in terms of airflow volume through the enclosed cabinet space; and said series of values of said actual trend comprises a series of airflow values that define an actual airflow trend, wherein each of said series of airflow values is derived from one or more of said air pressure differential measurements. ### Claim 9 (depends on 8) The airflow health predictive maintenance system as set forth in claim 8, wherein said electronic control system is further configured to: compare said projected trend to said setpoint to determine said end of life event when said projected trend equals said airflow volume setpoint. ### Claim 10 (depends on 9) The airflow health predictive maintenance system as set forth in claim 9, wherein said electronic control system is configured to output a warning that provides information about expected timing of said end of life event to at least one of: (i) a human machine interface; and (ii) a network interface. ### Claim 11 (depends on 10) The airflow health predictive maintenance system as set forth in claim 10, wherein said electronic control system is further configured to adjust the airflow volume setpoint based upon at least one of: (i) operational loading associated with the motor drive; (ii) temperature of an ambient atmosphere surrounding the motor drive; (iii) air quality in terms of concentration of particulates or other contaminants of the ambient atmosphere; and (iv) altitude of the motor drive. ### Claim 12 (depends on 11) The airflow health predictive maintenance system as set forth in claim 11, wherein said at least one fan comprises multiple fans of which one of said multiple fans is a primary fan, and wherein said differential pressure sensor senses said air pressure differential measurements across said primary fan between said fan inlet of said primary fan and said fan outlet of said primary fan. ### Claim 13 (depends on 12) The airflow health predictive maintenance system as set forth in claim 12, wherein said electronic control system increases said air pressure differential measurements by a select compensation amount when said air pressure differential measurements are taken when said primary fan is inactive and at least one other fan of said multiple fans is active. ### Claim 14 (depends on 13) The airflow health predictive maintenance system as set forth in claim 13, wherein said select compensation amount is related to a difference in the air pressure differential sensed by said differential pressure sensor when said primary fan is active as compared to when said primary fan is inactive. ### Claim 15 (depends on 7) The airflow health predictive maintenance system as set forth in claim 7, wherein said at least one fan comprises multiple fans of which one of said multiple fans is a primary fan, and wherein said differential pressure sensor senses said air pressure differential measurements across said primary fan between said fan inlet of said primary fan and said fan outlet of said primary fan. ### Claim 16 A method for airflow health predictive maintenance for a motor drive, said method comprising: operating a fan to induce airflow through an enclosed space of a cabinet of the motor drive, wherein said airflow enters the enclosed space through at least one air filter; sensing, by a differential pressure sensor, an air pressure differential created by said fan between a sensing location in communication with said enclosed space and a reference location external to the enclosed space to obtain an air pressure differential measurement that represents a vacuum pressure established within the enclosed space; and at least one of: (i) comparing said air pressure differential measurement to an air pressure differential setpoint and predicting when maintenance of said at least one air filter will be required; and (ii) deriving a volume of said airflow based upon said air pressure differential measurement, comparing said volume of said airflow to an airflow volume setpoint to predict when maintenance of said at least one air filter will be required. ### Claim 17 (depends on 16) The method for airflow health predictive maintenance as set forth in claim 16, said method further comprising: generating an actual trend of air pressure differential values where each of said air pressure differential values is derived from at least one said air pressure differential measurement; extrapolating said actual trend of air pressure differential values to derive a predicted trend of air pressure differential values; and comparing said predicted trend of air pressure differential values to said air pressure differential setpoint to predict an end of life event for said at least one air filter. ### Claim 18 (depends on 17) The method for airflow health predictive maintenance as set forth in claim 17, further comprising: periodically dynamically adjusting said air pressure differential setpoint based upon at least one of: (i) operational loading of the motor drive; (ii) ambient temperature relative surrounding the motor drive; and (iii) altitude of the motor drive. ### Claim 19 (depends on 16) The method for airflow health predictive maintenance as set forth in claim 16, said method further comprising: generating an actual trend of airflow volume values where each of said airflow volume values is derived from at least one said air pressure differential measurement; extrapolating said actual trend of airflow volume values to derive a predicted trend of airflow volume; and comparing said predicted trend of airflow volume to said airflow volume setpoint to predict an end of life event for said at least one air filter. ### Claim 20 (depends on 19) The method for airflow health predictive maintenance as set forth in claim 19, further comprising: periodically dynamically adjusting said airflow volume setpoint based upon at least one of: (i) operational loading of the motor drive; (ii) ambient temperature relative surrounding the motor drive; and (iii) altitude of the motor drive.