A container unit's microprocessor-controlled temperature controller is set at -28.9°C, appropriate for a frozen cargo of ice cream. In this mode of operation, according to the illustrated temperature controller functional diagrams, what should be the operational status of the unit if the actual box temperature is -18.0°C? Illustration GS-RA-035

Illustration GS-RA-035: the U.S. Coast Guard has not released this illustration.

Question

A container unit's microprocessor-controlled temperature controller is set at -28.9&deg;C, appropriate for a frozen cargo of ice cream. In this mode of operation, according to the illustrated temperature controller functional diagrams, what should be the operational status of the unit if the actual box temperature is -18.0&deg;C? Illustration GS-RA-035

Illustration GS-RA-035: the U.S. Coast Guard has not released this illustration.

Accepted Answer

Option A: cooling mode. When the actual box temperature of -18.0°C is significantly warmer than the micro-processor setpoint of -28.9°C for frozen cargo, the controller demands active heat removal, placing the container unit into the cooling mode to lower cargo space temperature.