Trailer refrigeration unit and methods for limiting the supply air temperature thereof

A method of operating a trailer refrigeration unit of a refrigerated trailer system comprising:

• setting a cargo hold set point temperature through a user interface;
• urging an airflow along a flowpath from a return air inlet port, through an evaporator of the trailer refrigeration unit, and to a supply air outlet port of the trailer refrigeration unit;
• monitoring a return air temperature of the airflow flowing through the return air inlet port;
• monitoring a supply air temperature of the airflow flowing through the supply air outlet port;
• heating the airflow flowing through the supply air outlet port when the return air temperature is less than the cargo hold set point temperature;
• and
• stopping heating of the airflow flowing to the supply air outlet port when the return air temperature is less than the cargo hold set point temperature and the supply air temperature reaches a threshold wherein heating the airflow further comprises activating one or more electric heaters disposed in thermal communication with the airflow, activating a hot gas bypass operation mode of the trailer refrigeration unit or activating one or more electric heaters disposed in thermal communication with the airflow and activating a hot gas bypass operation mode, resulting in heating the airflow through the evaporator, and
• wherein stopping heating of the airflow further comprises de-energizing the one or more electric heaters for a timed duration, de-activating the hot gas bypass operation, or both.