Abstract: Systems and methods are provided and include first and second case controllers for first and second refrigeration cases. The first case controller receives a first air temperature value of the first refrigeration case and communicates the first air temperature value to the second case controller. The second case controller receives a second air temperature value, determine an evaporator saturated suction temperature (SST) value, controls an evaporator pressure regulator based on a comparison of the evaporator SST value with an evaporator SST setpoint, determines an air temperature control value, determines whether the air temperature control value is within a predetermined range of an air temperature setpoint, and adjusts the evaporator SST setpoint in response to the air temperature control value being outside of the predetermined range of the air temperature setpoint.

Abstract: Systems and methods are provided and include a case controller for a refrigeration case of a refrigeration system. The case controller is configured to: determine an evaporator saturated suction temperature (SST) of an evaporator of the refrigeration case; control an evaporator pressure regulator of the refrigeration system based on a comparison of the evaporator SST with an evaporator saturated suction temperature (SST) setpoint; receive an air temperature value from an air temperature sensor associated with the refrigeration case; determine whether the air temperature value is within a predetermined range of an air temperature setpoint; and adjust the SST setpoint in response to the air temperature value being outside of the predetermined range of the air temperature setpoint.

Abstract: A refrigeration system includes first and second compressors, a condenser, first and second refrigeration cases, and a system controller. The first and second compressors are fluidly connected to respective first and second suction and discharge lines. The second suction line is fluidly connected to the first discharge line. The condenser receives refrigerant from the second compressor. The first and second refrigeration cases operate within respective first and second temperature ranges, the first range being lower than the second range. The first case includes a first evaporator that receives refrigerant from the condenser and discharges refrigerant to the first suction line. The second case includes a second evaporator that receives refrigerant from the condenser and discharges refrigerant to the second suction line. The system controller identifies when maintenance is necessary based on a first discharge temperature of the refrigerant in the first discharge line.

Abstract: A system and method of controlling a compressor rack having a plurality of variable capacity components is provided. A variable capacity component is selected from the plurality of variable capacity components as a designated variable capacity component. The designated variable capacity component is operated by varying a capacity of the designated variable capacity component. Each variable capacity component of the plurality of variable capacity components, except for the designated variable capacity component, is operated at a fixed capacity corresponding to one of a maximum and a minimum capacity of the variable capacity component.

Abstract: A controller and method for control of a refrigeration system having a compressor rack operable at a plurality of capacities may include determining a rate of change in suction pressure for a first capacity, determining a rate of change in suction pressure associated with a second capacity, and determining which of the first capacity and the second capacity will produce the least variation between a measured suction pressure and a desired suction pressure based on the rate of change in suction pressure associated with each.

Abstract: A system and method of controlling components of a refrigeration system includes determining a desired rate of change of a refrigeration system operating parameter, using historical data to predict an expected rate of change of the operating parameter for cycling each component, calculating an appropriateness factor for each component corresponding to a difference between the expected rate of change for the component and the desired rate of change, ranking the components based on the appropriateness factor, and selectively cycling at least one component based on the ranking.

Abstract: A system and method of controlling a compressor rack having a plurality of variable capacity components is provided. A variable capacity component is selected from the plurality of variable capacity components as a designated variable capacity component. The designated variable capacity component is operated by varying a capacity of the designated variable capacity component. Each variable capacity component of the plurality of variable capacity components, except for the designated variable capacity component, is operated at a fixed capacity corresponding to one of a maximum and a minimum capacity of the variable capacity component.

Abstract: A controller and method for control of a refrigeration system having a compressor rack operable at a plurality of capacities may include determining a rate of change in suction pressure for a first capacity, determining a rate of change in suction pressure associated with a second capacity, and determining which of the first capacity and the second capacity will produce the least variation between a measured suction pressure and a desired suction pressure based on the rate of change in suction pressure associated with each.

Abstract: A system and method of controlling components of a refrigeration system includes determining a desired rate of change of a refrigeration system operating parameter, using historical data to predict an expected rate of change of the operating parameter for cycling each component, calculating an appropriateness factor for each component corresponding to a difference between the expected rate of change for the component and the desired rate of change, ranking the components based on the appropriateness factor, and selectively cycling at least one component based on the ranking.