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US 11,692,726 B2Granted
System and method for distinguishing HVAC system faults
AssigneeLennox Industries Inc.
InventorsAmita Brahme, Umesh Gokhale
Life of this patent
Estimating the term…
Abstract
A controller of an HVAC system is communicatively coupled to a liquid-side sensor and a shutoff switch. The controller stores measurements of a liquid-side property over an initial period of time. The controller detects that the shutoff switch is tripped at a first time stamp corresponding to an end of the initial period of time. The controller accesses the measurements of the liquid-side property. The controller determines, based on the measurements of the liquid-side property, that the liquid-side property has a decreasing trend. In response to determining that the liquid-side property has the decreasing trend, a malfunction of a blower of the system is determined to have caused the shutoff switch to trip.
Claims20
A heating, ventilation and air conditioning (HVAC) system comprising:
- a refrigerant conduit subsystem configured to allow a flow of refrigerant through the HVAC system;
- a compressor configured to receive refrigerant and direct the refrigerant to flow through a refrigerant conduit subsystem;
- an evaporator configured to receive the refrigerant and allow heat transfer between the refrigerant and a flow air across the evaporator;
- a blower configured to provide the flow of air across the evaporator;
- a suction-side sensor positioned and configured to measure a suction-side property associated with refrigerant provided to an inlet of the compressor, wherein the suction-side property comprises at least one of a suction-side temperature or a suction-side pressure;
- a shutoff switch communicatively coupled to the suction-side sensor and configured to be tripped and automatically stop operation of the compressor and blower in response to determining that the suction-side property is less than a predefined minimum value;
- a liquid-side sensor positioned and configured to measure a liquid-side property associated with the refrigerant provided from an outlet of the compressor, wherein the liquid-side property comprises at least one of a liquid-side temperature or a liquid-side pressure;
- and
- a controller communicatively coupled to the shutoff switch and the liquid-side sensor, the controller configured to:
- store measurements of the liquid-side property over an initial period of time;
- detect that the shutoff switch is tripped at a first time stamp corresponding to an end of the initial period of time;
- access the measurements of the liquid-side property;
- determine, based on the measurements of the liquid-side property, that the liquid-side property has a decreasing trend;
- and
- in response to determining that the liquid-side property has the decreasing trend, determine that a malfunction of the blower caused the shutoff switch to trip.
12 more elements
A method of operating a heating, ventilation and air conditioning (HVAC) system, the method comprising:
- storing measurements of a liquid-side property over an initial period of time, wherein the liquid-side property comprises at least one of a liquid-side temperature or a liquid-side pressure and is associated with refrigerant provided from an outlet of a compressor of the HVAC system;
- detecting that a shutoff switch is tripped at a first time stamp corresponding to an end of the initial period of time, wherein the shutoff switch is configured to be tripped and automatically stop operation of the compressor and a blower of the HVAC system in response to determining that a suction-side property is less than a predefined minimum value, wherein the suction-side property comprises at least one of a suction-side temperature or a suction-side pressure and is associated with the refrigerant provided to an inlet of the compressor;
- accessing the measurements of the liquid-side property;
- determining, based on the measurements of the liquid-side property, that the liquid-side property has a decreasing trend;
- and
- in response to determining that the liquid-side property has the decreasing trend, determining that a malfunction of the blower caused the shutoff switch to trip.
3 more elements
A controller of heating, ventilation and air conditioning (HVAC) system, the controller comprising:
- an input/output interface communicatively coupled to:
- a shutoff switch configured to be tripped and automatically stop operation of a compressor and a blower of the HVAC system in response to determining that a suction-side property is less than a predefined minimum value, wherein the suction-side property comprises at least one of a suction-side temperature or a suction-side pressure and is associated with refrigerant provided to an inlet of the compressor;
- and
- a liquid-side sensor positioned and configured to measure a liquid-side property, wherein the liquid-side property comprises at least one of a liquid-side temperature or a liquid-side pressure and is associated with the refrigerant provided from an outlet of the compressor;
- and
- a processor, coupled to the input/output interface, the processor configured to:
- store measurements of the liquid-side property over an initial period of time;
- detect that the shutoff switch is tripped at a first time stamp corresponding to an end of the initial period of time;
- access the measurements of the liquid-side property;
- determine, based on the measurements of the liquid-side property, that the liquid-side property has a decreasing trend;
- and
- in response to determining that the liquid-side property has the decreasing trend, determine that a malfunction of the blower caused the shutoff switch to trip.
9 more elements
Dependencies are inferred from the claim text.