TM 9-4120-360-14
Section 111. OPERATION UNDER USUAL CONDITIONS
2.4. Operating Check
CAUTION
Do not perform the following operating checks until at least four hours after power has been connected to
the air conditioner if it has been stored at below-freezing temperatures within the past 24 hours. If knock-
ing or pounding noises are heard when the compressor is started, shut down at once. Leave power con-
nected to the unit, and wait an additional two hours before attempting another start.
Check operation of the air conditioner in each operating mode as directed in the following steps:
a. Unzip and roll up the fabric cover on the rear of the unit. Secure with two straps, and fasten with two turnbutton --
fasteners.
b. Using the operating lever, open the louvers of the evaporator air intake grille to their fully open positions. Open
both the vertical and the horizontal louvers in the evaporator air discharge grille to their open position.
c. Position the two-speed fan switch on the control panel at LO SPEED, and turn the mode selector switch to
VENTILATE. Check airflow with smoke or a paper streamer at both evaporator discharge and condenser discharge grilles.
d. Position the two-speed fan switch at HI SPEED. and observe increased airflow.
e. Turn mode selector switch to LO HEAT and turn temperature control thermostat to its full INCREASE position.
Feel evaporator discharge air with the hand to check for warmth. Turn mode selector switch to HI HEAT, and note increase in
warmth of airflow.
f. Turn selector switch to VENTILATE for one minute, then turn it to COOL. Turn the temperature control
thermostat to its full DECREASE position. Note that cool air is discharged from evaporator discharge grille.
g. Turn mode selector switch to OFF and observe that all functions cease.
2.5.
Operating Procedure
a. General. AU modes of operation are controlled from the control panel in the upper middle part of the lower
panel. Delivery airflow is controlled by the setting of louver blades in the evaporator discharge grille, and does not require -
changing except for minor adjustment to accommodate seasonal change or a desired change in the pattern of coverage.
b. Starting, Normally, the air conditioner will start whenever the mode selector switch is turned to any of the four
operating positions: VENTILATE, COOL. LO HEAT or HI HEAT. provided that it is connected to the proper power supply
(208-volt, 3-phase, 50/60 Hertz. ac). If the air conditioner fails to start. reset the circuit breaker by means of the pull-push -
knob on the back of the unit. If the air conditioner still fails to start, and you have determined that the proper electrical power
is connected to the unit, report the trouble to Unit maintenance.