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 D: cooling mode. When the actual cargo box temperature of -18.0°C is substantially warmer than the -28.9°C setpoint required for frozen ice cream, the microprocessor controller initiates the cooling mode to reduce the box temperature.