TM 9-4120-405-13&P
Section III. OPERATION UNDER USUAL CONDITIONS
2-6. ASSEMBLY AND PREPARATION FOR USE. Services of unit maintenance should be employed for original
unpacking, assembly installation, and preparation for use. See paragraph 4-6.
2-7. INITIAL ADJUSTMENTS AND CHECKS.
a. Inspect all covers, panels, screens for loose mounting, obstructions, or shipping damage. Report any deficiencies
to unit maintenance.
b. Perform the preventive maintenance checks and services listed in table 2-1.
2-8. OPERATIONAL CHECKS. The following general operational checks and explanations should be used and
understood to be sure that the trailer-mounted, generator-set powered, air conditioner will operate in the best possible
manner. Refer to figure 2-1 for location of operator's controls and indicators.
a. Perform the preventive maintenance checks and services in table 2-1.
b. Tie back canvas cover from air conditioner.
CAUTION
Always start the generator set and warm up the engine before turning air
conditioner ON.
c. Check that the air conditioning unit is properly connected to the generator set and that power has been on for 4
hours before starting air conditioner.
d. Check that flexible ducts are properly installed on shelter.
e. Check to see that the CONTROL CIRCUIT BREAKER and the COMPRESSOR CIRCUIT BREAKER o the air
n
conditioner are in the ON position.
f. On the air conditioner, turn the MODE SELECTOR switch to VENT. The evaporator fan should start immediately.
Use a paper streamer or other method to check the air flow into the return air duct and out of the conditioned air supply
duct.
NOTE
Air conditioner has been modified to ventilate with recirculated air only.
g. On the air conditioner, turn the TEMPERATURE SELECTOR (thermostat) knob to the fully WARMER (clockwise)
position. Then turn the MODE SELECTOR switch to LOW HEAT. Place your hand in the air flow from the conditioned air
supply louver and feel for a temperature rise.: When the supply air temperature has reached a relatively stable level, turn
the MODE SELECTOR switch to HIGH HEAT and feel for further temperature rise. Next, turn the TEMPERATURE
SELECTOR thermostat control knob to the fully COOLER (counterclockwise) position. Feel that supply air temperature
drops to approximately the same relatively stable level previously noted In LOW HEAT. Finally, turn the MODE
SELECTOR switch to LOW HEAT and feel the discharge air temperature drop to ambient level (room temperature).
NOTE
The temperature thermostat control has an effective functional range between 60 F
and 90 F (16 C and 32 C). In extreme conditions when ambient air temperature is
below 60 F (16 C) or above 90 F (32 C), the operation in either LOW HEAT or HIGH
HEAT mode will vary from that described above.
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