TM 9-4120-357-14
g. Sight-glass color change plate. This plate displays three color bands: green (dry), chartreuse (caution) and yel-
low (wet). For use in comparing the color of the moisture indicator in the liquid in the sight-glass liquid indicator.
h. Pressure cutout switch plate. Located above the pressure cutout switch reset buttons on the rear control panel,
this plate provides PUSH TO RESET instructions for re-setting the low- and high-pressure cutout switches.
i. Circuit breaker reset plate. This plate, located on the rear control panel displays PULL THEN PUSH TO RESET
instructions.
j. Circuit breaker access plate. This plate identifies the circular plate on the front access panel.
k. Fan warning plate. Located in the center of the condenser fan guard, this plate contains the words DANGER,
KEEP HANDS CLEAR, DANGER.
I. Wiring diagram plate. (See Figure 4-16) A
plate showing the wiring diagram of
the air conditioner is
mounted on
the face of the junction box cover.
m. Refrigeration diagram plate. A plate showing the refrigeration diagram is mounted on the inside surface of the
junction box cover.
n. Compressor data plate. A
plate mounted on
the compressor identifies the model number, part and serial num-
bers, refrigerant, and electrical characteristics of the compressor.
o. Condenser fan motor plate. Mounted on
the end bell of
the condenser fan motor, this plate specifies the horse-
power, type, serial number and electrical characteristics of the condenser fan motor.
p. Evaporator fan motor plate. This plate identifies the horsepower, type, serial number and electrical characteris-
tics of the evaporator fan motor.
q. Hearing protection required plate. This plate requires that hearing protection be worn when the air conditioner is
in operation for maintenance.
Section IV. OPERATION UNDER UNUSUAL CONDITIONS
2-15. Unusual Weather.
a. Snow. When operating in an environment of heavy snowfall, the fresh air damper should normally be kept closed
to avoid snow and ice buildup in the fresh air inlet grille and baffle. However, when cooling is required down to 0 , the
F
air conditioner cover and deflector door should remain open. Also the fresh air damper may have to be open for cooling
b. Sand and dust storms. Clean the air filters, mist eliminator, condenser coil and screen, and evaporator coil
weekly or more often if necessary. Disconnect power, remove front access panel, and flush out bottom panel carefully to
remove mud accumulation. Use care to avoid wetting electrical components.
c. Extreme heat. The air conditioner is designed to operate satisfactorily at temperatures up to 120F (48.9 ).
C
Make sure that all condenser and evaporator grilles and screens are fully open and unobstructed.
d. Extreme cold. The unit is designed to operate at a maximum low temperature of -50 (-45.6 ). Do not disturb
F
C
wiring during periods of extreme cold; the insulation and wires become brittle at low temperatures, and are easily broken.
The air conditioner cover and deflector door should normally be closed during cold weather when the unit is not in opera-
tion.
e. Salt air and sea spray. Wash the outside of the air conditioner frequently with clear fresh water, being careful to
avoid damaging electrical equipment. Coat exposed metal surfaces with corrosion resistant material as follows: use
touch up paint on damaged painted surfaces. Refinish or replace damaged plated parts.
f. Rain or extreme humidity. Keep air conditioner cover and deflector door closed when the unit is not in use for
cooling during rainy weather. Open covers to permit drying inside surfaces whenever possible before operating. Use
care when operating electrical equipment in damp or wet areas to avoid shock hazard.
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