TM 9-4120-357-14
b. Air conditioner cover. The air conditioner cover encloses the lower rear section of the air conditioner, including
the condenser fan outlet. The cover is retained in the closed position by a zipper around both sides and the bottom. It is
retained in the open position (rolled up) by two flaps fastened by turnbutton fasteners at the top of the panel. The cover
must be open at all times when the air conditioner is operating in the cooling mode.
c. CBR cover plate. The chemical-biological-radiological (CBR) cover plate is the circular plate located in the upper
right-hand portion of the air conditioner's rear surface. The plate covers the CBR intake when a CBR air filtering system
if not used.
2-4.
Rear Surface Controls and Indicators.
a. Circuit breaker reset. The circuit breaker reset knob is located on the rectangular recessed panel at the 9 o'clock
position from the condenser fan. The circuit breaker automatically disconnects electric power from the compressor and
24 v DC control circuit in case of an internal overload or short circuit of the compressor motor. It can be reset by pulling
then pushing the reset knob. If the circuit breaker trips repeatedly, or cannot be reset, report the trouble to unit mainte-
nance.
b. High- and low-pressure cutout switches. The pressure cutout switches are located at the top of the rectangular
recessed panel at the 10 o'clock position from the condenser fan. One or the other switch may open when refrigerant
pressure becomes too high or too low. To reset the switches, press then release each of the reset buttons. If one of the
switches trips repeatedly, report the trouble to direct support maintenance at once.
c. Sight-glass liquid indicator. The sight-glass liquid indicator is a circular gage located in the upper left-hand
portion of the rear surface of the air conditioner. The sight-glass shows the condition of the liquid refrigerant in the sys-
tem. Shortage of refrigerant is indicated by bubbles or a milky appearance of the liquid. Moisture is indicated by a
change of color from green to yellow. Either condition should be reported to direct support maintenance at once.
WARNING
Hearing protection must be worn when maintenance is
performed while air conditioner is in operation. Failure
to heed this warning can result in hearing loss or injury.
CAUTION
Bubbles may appear in the sight-glass when the hot gas
bypass valve is in operation with normal charge. To
verify that the refrigerant charge is in low, operate unit
at full load condition without the bypass open. If bub-
bles appear at full load condition with bypass closed,
addition of refrigerant is required.
2-5. Operating Settings.
The proper settings for air conditioning controls are as shown in Table 2-1.
2-3
