TM 9-4120-357-14
c. Drainage. The air conditioner has four plugged drain holes, one in
the middle of
each side of
the base plate. Wa-
ter vapor in the air is condensed to liquid form when the air conditioner operates in the cooling mode. The condensate is
collected in a drain pan below the evaporator coil, and is piped to the base plate. The condensate should be conducted
from one of the base plate drainage holes to a drain, storm sewer or dry sump. Standard half-inch plumbing fittings and
hoses may be used.
d. Mounting and framing. The air conditioner can be
mounted directly on
the floor, or on a
platform. (See Figure
2-2 for mounting details of
the base.) The unit measures 23-1/4 inches (59.06 cm) deep, 34
inches (86.36 cm) wide, and
65 inches (165.1 cm) high. It is recommended that wall framing be at least 36 x 72 inches to accommodate the unit.
The spaces at each side can be filled with plastic foam insulating material or the equivalent. The top space should be
closed with a removable filler strip, so that the top of the unit can be easily removed for servicing when necessary. Sat-
isfactory material for the filler strip may be locally fabricated of sheet metal or plywood.
e. Transit. If a unit is to be transported while mounted in a shelter, it is necessary to secure the top of the unit to the
shelter for stability. This is accomplished using the flush door rings located on each side of the unit close to the top.
2-11. Initial Adjustments and Daily Checks.
a. Cooling. During the cooling season, the condenser fan must have an
unrestricted supply of
air. Therefore, check
to be sure that the deflector door and the air conditioner cover are open before starting the unit. The evaporator intake
and discharge grilles must be open during all modes of operation except when 100 percent outside air is used. The
evaporator intake grille may be closed, and the fresh air damper open. Evaporator discharge grille blades may be ad-
justed at any time to direct air as desired.
b. Heating. During the heating season, the condenser fan does not operate. Therefore, the deflector door and the air
conditioner cover should be closed to reduce heat loss and to protect internal parts from the weather.
2-12. Operating Procedure.
Operating the air conditioner is extremely simple: set the selector switch to the desired mode (COOL, VENTILATE, LO
HEAT OR HIGH HEAT), and set the temperature control thermostat to provide the desired temperature. To stop the unit,
turn the selector switch to OFF.
2-13. Preparation For Movement.
The operator's responsibility for preparing the air conditioner for movement consists of turning the selector switch to
off, and closing all covers, dampers and grilles. If the unit has been operating in the cooling mode, it should not be dis-
connected from the power supply until several hours after it has been stopped. Refrigerant could condense in the com-
pressor and mix with the crankcase oil unless the crankcase heater remains on.
2-14. Operating Instructions on Decals and Instruction Plates.
The following instruction plates and decals are attached to the air conditioner. (See Figure 2-3, both sheets.)
a. Military identification plate. This plate contains information about the name, part number NSN, manufacturer,
contract number and serial number of the equipment. It is located on the upper left-hand corner of the rear surface.
b. Weight plate. Two weight plates, one near the middle of each side, indicate the gross weight of the air conditioner.
c. Refrigerant type and charge plate. This plate specifies the type and weight of refrigerant (R22) used to charge
the air conditioner's refrigeration system. The plate is located to the left of the fresh air intake grille on the condenser
side of the air conditioner.
d. Power supply plate. Three power supply plates, one near the bottom of the rear panel, and one about a foot from
the bottom of each side, specify the electric power to be connected to the air conditioner.
e. Control panel instruction plate. This plate, located in the upper left-hand corner of the front access panel, dis-
plays five positions of the mode selector switch (HI-HEAT, LO HEAT, OFF, VENTI LATE, COOL), and the range of tem-
perature adjustments for the temperature control thermostat (INCREASE, DECREASE).
f Damper control plate. One damper control plate is attached to the knob on each end of the damper control rod.
Each indicates the direction for OPEN, TURN, CLOSE.
2-9