Abstract: An auxiliary subcooling circuit for a transport refrigeration system (TRS) is provided. The auxiliary subcooling circuit may be configured to be driven by a compressor that is separate from a main compressor of a main refrigeration system of the TRS. The auxiliary subcooling circuit can be configured to subcool refrigerant in the main refrigeration system. The auxiliary subcooling circuit and the main refrigeration system may be configured to be driven by a prime mover of the TRS. An engaging device is configured to allow the auxiliary subcooling circuit to engage or disengage the prime mover. Methods to control the TRS are also provided.

Abstract: A system and method of maintaining multiple temperatures using a single refrigeration system. A single refrigeration system includes a compressor, reservoir, condenser and associated piping is selectively coupled to one of a plurality of evaporator units. Each evaporator unit has an inlet valve, an expansion valve and an evaporator. A sensor signals a microprocessor that one of the plurality of evaporators requires cooling, initiating a cooling cycle. The compressor is energized and the evaporator inlet valve opens, allowing refrigerant to flow through the evaporator unit. At the conclusion of the cooling cycle, the evaporator inlet valve closes while the compressor continues to operate allowing the removal or drawing down of the refrigerant from the evaporator prior to cooling another evaporator section. At the conclusion of the draw down process, the compressor is de-energized.