TM 9-4120-398-14
OPERATING TEMPERATURES
LOW
-50 F (-45 C)
+125 F (+46 C)
HIGH
PERFORMANCE
54,000 Btu/hr
COOLING CAPACITY
32,785 Btu/hr
POWER REQUIRED
VOLTAGE
208/230
PHASE
3
HERTZ
130 (starting)
AMPERAGE
25 (running)
10 kW
POWER
DIMENSIONS
48 in. (1219 mm)
71 in. (1803 mm)
HEIGHT
32 in. (812 mm)
WEIGHT
920 lb (417.68 kg)
REFRIGERANT
R-22
10 lb (4.54 kg)
CHARGE
Section III. TECHNICAL PRINCIPLES OF OPERATION
1-10. THEORY OF
OPERATION
a. COOLING. During air cooling operation, the compressor delivers refrigerant gas at high temperature and pressure to
the condenser. A fan blowing across the condenser coil carries away refrigerant heat, causing the refrigerant to condense from
a gas to a liquid, still under high pressure. From the condenser, the liquid refrigerant passes through an expansion (throttling)
valve, emerging as a liquid at lower pressure into the evaporator. The air to be conditioned is blown across the evaporator coils,
where heat is extracted causing the refrigerant to boil and become a heated gas. From the evaporator, refrigerant enters the
compressor to repeat the continuing cycle. A thermostat cycles the compressor for conditioned air temperature control.
b. AIRFLOW SYSTEM. As indicated in figure 1-3, the air conditioner is divided into two separate airflow
compartments. Cooled airflow takes place in the front compartment; heat rejection airflow takes place in the rear
compartment. A metal wall seals the front compartment from the rear, preventing air from passing between the two
compartments.
c. CONDENSER AIRFLOW. Heat-filled refrigerant is pumped into the condenser. A fan draws in outside air through
the finned condenser coil and delivers the heated air to the outside. Fan and coil are sized for adequate forced air cooling with
outside air entering at a temperature as high as125F.