TM 9-4120-405-13&P
CAUTION
If a knocking or pounding noise is heard when the compressor starts in the
following check, immediately turn the MODE SELECTOR out of the COOL position.
Leave input power connected and wait at least 2 hours before attempting another
start in COOL mode. Damage to equipment may result if personnel fail to observe
precautions.
h. On the air conditioner, turn the TEMPERATURE SELECTOR control knob to the fully WARMER (clockwise)'\
position, then turn the MODE SELECTOR switch to COOL. Note that the evaporator and condenser fans start
immediately and that the compressor starts approximately 30 seconds later. Hold your hand in the air flow from the
conditioned air supply louver; there should be no change in temperature. Now turn the TEMPERATURE SELECTOR
control knob to the fully COOLER (counterclockwise) position and feel the supply air temperature begin to drop almost
immediately. Leave controls in the present position and perform the next check.
i. After 15 minutes of operation, check the sight glass to determine the refrigerant condition. Th e sight glass is
equipped with a center indicator that is moisture sensitive. Dry refrigerant is indicated by green, it turns to chartreuse
when the moisture content becomes undesirable, and to yellow when the level becomes unacceptable. Excessive
moisture in the refrigerant may damage or possibly destroy the compressor. If the liquid refrigerant observed in the sight
glass has a milky appearance, or frequent bubbles appear, the volume of refrigerant is low and the system should be
charged. Either moisture or low charge indications should be reported to supervisor for appropriate refrigeration system
action.
CAUTION
Do not operate the air conditioner in the COOL mode if the refrigerant color has
reached the yellow band or if numerous bubbles appear in the sight glass. COOL
mode operation may be continued with the refrigerant color in the chartreuse band
or with only an occasional bubble appearing in the window, but the sight glass
should be rechecked after each 4 hours of operation to ensure that the condition
has not become worse. Damage to the equipment may result if personnel fail to
observe precautions.
j. Turn the MODE SELECTOR switch to OFF. Observe that all air conditioner functions cease.
2-9. GENERAL OPERATING PROCEDURES.
a. Generator Set.
WARNING
All personnel involved in the operation or maintenance of the generator set should
become thoroughly familiar with the safety precautions prior to performing
operation or maintenance procedures.
Prior to connection of load cables, make sure all switches are in OFF or OPEN
position and the generator set is not operating.
Inspect the generator-set ground connection prior to starting the unit. Electrical
defects in load lines or load equipment can cause death by electrocution when
contact is made with an ungrounded system.
Do not smoke or carry an open flame when servicing the batteries or fuel tank.
Exercise extreme care to prevent electrical arcing in the area of the batteries.
Battery electrolyte contains sulfuric acid and can cause severe burns. Handle it
with care. If the electrolyte comes in contact with the body, eyes, or clothing, rinse
immediately with clean water. Avoid spilling electrolyte on painted surfaces. Do
not work alone or smoke when servicing batteries.
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