Section III. PRINCIPLES OF OPERATION
1-12. SYSTEM TECHNICAL PRINCIPLES OF OPERATION.
Refrigerated Container. The refrigerated container is designed for use with the Model CH-609-32
Refrigeration Unit installed on the front wall panel. Power to operate the refrigeration unit and the container
interior light is provided by the 10KW generator set. The refrigerated container is a framed, insulated box
that prevents the thermal transfer of heat into or out of the container. Both interior walls and the floor are
ribbed to permit proper air circulation around cargo when the container is fully loaded. Two insulated and
sealed exterior door panels open the full width of the container to allow easy loading and unloading. A light
inside the container is controlled by a switch mounted on the interior wall. A fuel tank, mounted on the front
of the container, stores extra fuel for the Generator Set.
Refrigeration System. Interior container temperature is controlled and maintained by the refrigeration unit
mounted on and through the front wall section of the refrigerated container. The refrigeration unit consists of
provides cooling by heat absorption, and heating through the use of electrical resistance elements (TM 9-
4110-252-14). Electrical power to operate the refrigeration unit is supplied by the 10KW generator set. An
external power source may also be used in place of the generator set.
1-13. COMPONENT TECHNICAL PRINCIPLES OF OPERATION.
Container. Insulation built into the walls, floor, and ceiling reduces the gain and/or loss of heat between the
container interior and ambient conditions.
Doors. Two doors provide access to the container interior. Each door is insulated and seals tightly against
the container frame when closed. The right access door contains an emergency escape door to prevent
entrapment of personnel. The emergency door can only be removed from inside the container.
Light. The 100 watt interior light receives electrical power from the power cord plugged into the 110-volt
receptacle on the generator set (refer to TM 5-6115-585-12/34). The light is controlled by a hand operated
switch mounted overhead near the right door.
Fuel Tank. The metal 26 gallon fuel tank stores fuel for the generator set Fuel level is indicated by the float
actuated fuel gage. Fuel lines connect the tank to the generator set (refer to TM 5-6115-585-12/34 for fuel
Temperature Recorder. The temperature recorder maintains a 24 hour record of the container's internal
temperature. A sensing bulb, mounted on the inside container wall, causes the cartridge pen to move up or
down on the paper chart. At the same time, a spring driven timer turns the chart paper. As the pen moves
along the paper, a permanent 48 hour record of the time and temperature is made. The timer must be
wound at least every 30 days.