Abstract: A method for monitoring compressor performance in a refrigeration system includes calculating an isentropic efficiency of a compressor of the refrigeration system, averaging isentropic efficiency over a predetermined period, comparing the average to an efficiency threshold, and detecting a compressor malfunction based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for monitoring refrigerant in a refrigeration system includes calculating a saturation temperature of refrigerant in a refrigeration system based on at least one of a discharge pressure and a discharge temperature of the refrigeration system; calculating an expected refrigerant level based on the saturation temperature; comparing the refrigerant level with the refrigerant level threshold; and generating a leak notification when the receiver refrigerant level is less than the refrigerant level threshold. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A system includes a compressor temperature sensor that generates a compressor discharge temperature signal corresponding to a compressor of a refrigeration system, a compressor pressure sensor that generates a compressor discharge pressure signal corresponding to the compressor, and a controller processing the signals over a predetermined time period. The processing includes calculating a discharge saturation temperature based on the compressor discharge pressure signal, calculating compressor superheat data based on the compressor discharge temperature signal and the discharge saturation temperature, accumulating the compressor superheat data over the predetermined time period, and comparing the accumulated compressor superheat data to a predetermined threshold. The controller generates an alarm indicating a compressor fault based on the comparing.

Abstract: A system for monitoring a remote refrigeration system includes a plurality of sensors that monitor parameters of components of the refrigeration system and a communication network that transfers signals generated by each of the plurality of sensors. A management center receives the signals from the communication network and processes the signals to determine an operating condition of at least one of the components. The management center generates an alarm based on the operating condition.

Abstract: A compressor includes an orbiting member and a non-orbiting member mounted relative the orbiting member to define first and second chambers disposed between the orbiting and non-orbiting members. The non-orbiting member forms a seal to generally prevent fluid communication between the first and second chambers when in a first position and breaks the seal to allow fluid communication between the first and second chambers when in a second position. A structure supports the orbiting and non-orbiting members for relative orbital movement therebetween and a time pulsed actuation apparatus is coupled to the structure and configured to selectively break the seal.

Abstract: A control system for a cooling system includes a first sensor for sensing a property indicative of demand for cooling and a controller coupled to the sensor. The controller produces the variable duty cycle control signal in response to the property and causes the compressor and valve to vary a cooling capacity of the cooling system in response to the variable duty cycle control signal. The sensor may sense the pressure, temperature, or both. The valve may be a suction-side pressure regulator or a liquid-side expansion valve of the solenoid or stepper type.

Abstract: A controller includes a first input that receives a signal indicating an energy consumption value of a compressor, a second input that receives a signal indicating an energy consumption value of a variable speed condenser fan, a third input that receives a signal indicating an ambient temperature, a fourth input that receives a signal indicating a condenser temperature, an output that provides a control signal to the variable speed condenser fan, a memory that stores a temperature difference set-point, and a processor in communication with the inputs, the output and the memory. The processor calculates a difference between the ambient temperature and the condenser temperature, compares the difference with the temperature difference set-point, controls the variable speed condenser fan based on the comparison, monitors the energy consumption values, and modulates the temperature difference set-point to minimize energy consumption.

Abstract: A method is provided that includes receiving a plurality of event records, each including operating data of at least one of a building system and a building system controller; storing an event record queuing instruction; and ordering an event record queue by applying the event record queuing instruction to each event record. Each event record in the event record queue may be assessed based on the ordering.

Abstract: A controller comprises a first input that receives a signal indicating an energy consumption value of a compressor, a second input that receives a signal indicating an energy consumption value of a variable speed condenser fan, and an output that provides a control signal to the variable speed condenser fan. The controller also comprises a memory that stores a condenser set point, and a processor in communication with the input, output and memory and that modulates the condenser set-point to minimize energy consumption and controls the variable speed condenser fan based on the condenser set-point.

Abstract: A method for monitoring refrigerant in a refrigeration system includes calculating a saturation temperature of refrigerant in a refrigeration system based on at least one of a discharge pressure and a discharge temperature of the refrigeration system; calculating an expected refrigerant level based on the saturation temperature; comparing the refrigerant level with the refrigerant level threshold; and generating a leak notification when the receiver refrigerant level is less than the refrigerant level threshold. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for monitoring a condenser in a refrigeration system includes calculating a thermal efficiency of the condenser based on operation of the condenser and averaging the thermal efficiency over a predetermined period. Further, the method comprises comparing the average to an efficiency threshold and generating a notification based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for monitoring compressor performance in a refrigeration system includes calculating an isentropic efficiency of a compressor of the refrigeration system, averaging isentropic efficiency over a predetermined period, comparing the average to an efficiency threshold, and detecting a compressor malfunction based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method of proofing a refrigeration system operating state includes monitoring a change in operating state of a refrigeration system component, determining an expected operating parameter of the refrigeration system component as a function of the change, and detecting an actual operating parameter of the refrigeration system component after the change. The method also comprises comparing the actual operating parameter to the expected operating parameter of the refrigeration component and detecting a malfunction of the refrigeration system component based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for monitoring refrigerant in a refrigeration system includes sensing, a refrigerant pressure of a refrigeration system, averaging the refrigerant pressure over a time period, determining an expected pressure based on said time period, comparing the average to the expected pressure, and determining a system condition based on said comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for predicting maintenance in a refrigeration system includes counting occurrences of a compressor operating event and calculating a cumulative total of the compressor operating events. The method also comprises comparing the cumulative total with an operating threshold and estimating a time period until the cumulative total exceeds the operating threshold. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method for monitoring refrigerant in a refrigeration system includes calculating a return gas superheat of a refrigeration system and averaging the return gas superheat over a predetermined period. The method also comprises comparing the average to a superheat threshold and detecting at least one of a flood back condition and a degraded performance condition based on the comparison. The method may be executed by a controller or stored in a computer-readable medium.

Abstract: A method includes monitoring a system for fault conditions, determining an estimated energy loss based on the fault condition, determining an estimated product loss and/or sales loss based on the fault condition, and scheduling maintenance to correct the fault condition. Maintenance is schedule to correct the fault condition prior to the energy loss and the product loss exceeding maintenance costs.

Abstract: A method and apparatus for refrigeration system control includes a control system operable to modulate a suction pressure of each of the refrigeration circuits by controlling an evaporator pressure regulator respectively associated with each of the refrigeration circuits independently of evaporator refrigerant superheat to meet cooling demand. A sensor assembly provides refrigeration case temperature and evaporator pressure regulator valve position data to the control system to determine cooling demand.

Abstract: A system includes a scroll compressor having a first scroll member interleaved with a second scroll member to define at least two moving fluid pockets that decrease in size as they move from a radially outer position to a radially inner position. A valve in fluid communication with the compression chamber is movable between an open state allowing fluid to the compression chamber and a closed state preventing fluid to the compression chamber. A controller continuously cycles the valve between the open state and the closed state at a rate that is faster than a thermal time constant of a load on the system.

Abstract: A compressor includes an orbiting member and a non-orbiting member mounted relative the orbiting member to define first and second chambers disposed between the orbiting and non-orbiting members. The non-orbiting member forms a seal to generally prevent fluid communication between the first and second chambers when in a first position and breaks the seal to allow fluid communication between the first and second chambers when in a second position. A structure supports the orbiting and non-orbiting members for relative orbital movement therebetween and a time pulsed actuation apparatus is coupled to the structure and configured to selectively break the seal.