US 11,768,000 B2
System and method to operate HVAC system during voltage variation event
Shaun B. Atchison, Wichita, KS (US); and Theresa N. Gillette, Wichita, KS (US)
Assigned to Johnson Controls Tyco IP Holdings LLP, Milwaukee, WI (US)
Filed by Johnson Controls Technology Company, Auburn Hills, MI (US)
Filed on Mar. 24, 2020, as Appl. No. 16/828,813.
Prior Publication US 2021/0302039 A1, Sep. 30, 2021
Int. Cl. G05B 15/02 (2006.01); F24F 11/32 (2018.01); F24F 11/52 (2018.01); F24F 11/56 (2018.01); F24F 11/65 (2018.01); F24F 11/64 (2018.01); F24F 140/60 (2018.01); F24F 140/50 (2018.01)
CPC F24F 11/32 (2018.01) [F24F 11/52 (2018.01); F24F 11/56 (2018.01); F24F 11/64 (2018.01); F24F 11/65 (2018.01); G05B 15/02 (2013.01); F24F 2140/50 (2018.01); F24F 2140/60 (2018.01)] 20 Claims
OG exemplary drawing
 
1. A controller for a heating, ventilation, and/or air conditioning (HVAC) system, wherein the controller is configured to:
detect an input voltage received as a power supply by the HVAC system;
determine the input voltage exceeds a threshold value;
in response to determining that the input voltage exceeds the threshold value:
identify a voltage variation event in response to a determination that a duration of time during which the input voltage exceeds the threshold value is greater than a first threshold time period; and
identify the voltage variation event in response to a determination that the input voltage trends away from the threshold value for a second threshold time period, wherein the second threshold time period is less than the first threshold time period; and
operate a vapor compression system of the HVAC system in a de-rated operating mode to condition an air flow in response to identifying the voltage variation event.