Abstract: A condenser unit including a compressor for compressing a refrigerant vapor to provide a superheated refrigerant vapor exerting a head pressure, and a condenser for receiving the superheated refrigerant vapor and condensing the superheated refrigerant vapor therein, the condenser being located in an uncontrolled space with air therein at an ambient temperature. The condenser unit also includes a flow control means for controlling flow of the superheated refrigerant vapor from the compressor into the condenser, a rotatable condenser fan for moving air past the condenser to dissipate heat from the condenser, and a controller for controlling the flow control means and the speed of rotation of the condenser fan based on at least one preselected parameter, to maintain the head pressure within a predetermined range thereof.

Abstract: A condenser assembly through which a refrigerant is circulated to transfer heat from the refrigerant to ambient air in which the condenser assembly is at least partially disposed. The condenser assembly includes a compressor, a crankcase heater energizable via a crankcase heater control circuit, a condenser, a condenser fan, and an electronically commutated condenser fan motor. The condenser assembly also includes an ambient temperature sensor for sensing at least one temperature of the ambient air, to provide a sensed temperature. The condenser assembly includes a condenser switch subassembly configured to control energization of the crankcase heater and the condenser fan motor. The condenser switch subassembly is controlled by the ambient temperature sensor. The condenser fan motor is controlled by a condenser fan controller that applies a first voltage or a second voltage to the condenser fan motor depending on whether a third conductor attached to the motor is energized.

Abstract: A method of operating an evaporator assembly in which a refrigerant is circulatable to transfer heat out of air in a housing. The evaporator assembly includes a thermostat that completes a solenoid control circuit when the temperature of the air in the housing is above a predetermined cut-in temperature, and opens the solenoid control circuit when the temperature of the air is below a predetermined cut-out temperature. The thermostat completes a fan control circuit when the solenoid control circuit is open, and opens the fan control circuit when the solenoid control circuit is completed. A fan controller detects a signal voltage when the fan control circuit is completed, and provides a first predetermined drive voltage to a fan motor drive. Upon the fan controller failing to detect the signal voltage, a second predetermined drive voltage being greater than the first predetermined drive voltage is provided to the motor drive.

Abstract: A condenser assembly through which a refrigerant is circulated to transfer heat from the refrigerant to ambient air in which the condenser assembly is at least partially disposed. The condenser assembly includes a compressor, a crankcase heater energizable via a crankcase heater control circuit, a condenser, a condenser fan, and an electronically commutated condenser fan motor. The condenser assembly also includes an ambient temperature sensor for sensing at least one temperature of the ambient air, to provide a sensed temperature. The condenser assembly includes a condenser switch subassembly configured to control energization of the crankcase heater and the condenser fan motor. The condenser switch subassembly is controlled by the ambient temperature sensor. The condenser fan motor is controlled by a condenser fan controller that applies a first voltage or a second voltage to the condenser fan motor depending on whether a third conductor attached to the motor is energized.

Abstract: A condenser unit including a compressor for compressing a refrigerant vapor to provide a superheated refrigerant vapor exerting a head pressure, and a condenser for receiving the superheated refrigerant vapor and condensing the superheated refrigerant vapor therein, the condenser being located in an uncontrolled space with air therein at an ambient temperature. The condenser unit also includes a flow control means for controlling flow of the superheated refrigerant vapor from the compressor into the condenser, a rotatable condenser fan for moving air past the condenser to dissipate heat from the condenser, and a controller for controlling the flow control means and the speed of rotation of the condenser fan based on at least one preselected parameter, to maintain the head pressure within a predetermined range thereof.

Abstract: A method of operating an evaporator assembly in which a refrigerant is circulatable to transfer heat out of air in a housing. The evaporator assembly includes a thermostat that completes a solenoid control circuit when the temperature of the air in the housing is above a predetermined cut-in temperature, and opens the solenoid control circuit when the temperature of the air is below a predetermined cut-out temperature. The thermostat completes a fan control circuit when the solenoid control circuit is open, and opens the fan control circuit when the solenoid control circuit is completed. A fan controller detects a signal voltage when the fan control circuit is completed, and provides a first predetermined drive voltage to a fan motor drive. Upon the fan controller failing to detect the signal voltage, a second predetermined drive voltage being greater than the first predetermined drive voltage is provided to the motor drive.

Abstract: An evaporator assembly through which a refrigerant is circulated to transfer heat out of a volume of air in a housing in which the evaporator assembly is at least partially disposed. The evaporator assembly includes an evaporator in fluid communication with a compressor for compressing the refrigerant, a solenoid valve subassembly for controlling circulation of the refrigerant, a thermostat electrically connectable to the solenoid valve subassembly via a solenoid control circuit, one or more fans for circulating the air in the housing, and one or more fan motors for rotating the fans. Drive voltage supplied to the fan motors is controlled by a fan controller. The fan controller provides a first predetermined drive voltage to the motor drive when refrigerant is circulatable and a second predetermined drive voltage to the motor drive when refrigerant is non-circulatable.

Abstract: An evaporator assembly through which a refrigerant is circulated to transfer heat out of a volume of air in a housing in which the evaporator assembly is at least partially disposed. The evaporator assembly includes an evaporator in fluid communication with a compressor for compressing the refrigerant, a solenoid valve subassembly for controlling circulation of the refrigerant, a thermostat electrically connectable to the solenoid valve subassembly via a solenoid control circuit, one or more fans for circulating the air in the housing, and one or more fan motors for rotating the fans. Drive voltage supplied to the fan motors is controlled by a fan controller. The fan controller provides a first predetermined drive voltage to the motor drive when refrigerant is circulatable and a second predetermined drive voltage to the motor drive when refrigerant is non-circulatable.