Abstract: A transport refrigeration unit for cooling the interior of a cargo box having multiple cargo compartments includes a refrigerant compressor, a main evaporator associated with a first compartment of the trailer and a remote evaporator associated with a second compartment of the cargo box. During loading of product into at least one compartment, a controller determines the degree of superheat (CSS) in the refrigerant, compares the degree of suction superheat (CSS) to a lower limit for the degree of superheat (LSS), and continues operation of the refrigerant unit in a refrigeration mode if the degree of suction superheat (CSS) is greater than the lower limit for the degree of superheat (LSS); or terminates operation of the refrigerant unit in the refrigeration mode if the degree of suction superheat (CSS) is not greater than the lower limit for the degree of superheat (LSS) and initiates a defrost of at least one of the evaporators.

Abstract: In a transport refrigeration system which is susceptible to having its drive motors connected to a power source in reverse phase relationship to thereby operate the drive motors in reverse, provision is made to measure the current flow to the motors during operation in each direction and for comparing those current flows to determine which is greater and therefore representative of operation in the proper direction. A backup method is also provided for sensing the ambient temperature of the air downstream of the condenser coil, both before and during motor operation to determine whether the temperature during motor operation is greater than that prior to operation to thereby indicate a proper connection.

Abstract: A trailer refrigeration unit has a pivotally mounted engine driven generator unit and a pivotally mounted compressor unit that combine to form a structure that minimizes the spatial "real estate" occupied by the refrigeration unit. A single common rotatable shaft operates the integrally mounted engine and generator to form a unitary unit. The engine driven generator and compressor units can be pivoted out of the refrigeration unit frame to a fully serviceable position that provides easy access to the rear portions of the engine, generator and compressor units without requiring removal of those units from the refrigeration unit.