TM 9-4120-399-14
NOTE
Milky white or bubbly liquid means the system has a low charge. Clear
bubble-free liquid around the center means the system is fully charged.
u. If charge is low, add gas refrigerant.
(1) Be sure that cylinder is switched to gas position. Open the drum valve.
(2) Continue to charge until sight glass is clear and bubble-free.
(3) Close the refrigerant cylinder valve.
v. Check air conditioner for proper cooling. There should be at least a 15 F temperature
difference between evaporator discharge air and the inlet air. Turn the mode selector switch to
OFF.
WARNING
DANGEROUS CHEMICAL
(R22)
is used in this equipment.
DEATH
or severe injury may result if personnel fail to observe safety precautions. Use great
care to avoid contact with liquid refrigerant gas being discharged under pressure.
Sudden and irreversible tissue damage can result from freezing. Wear thermal
protective gloves and a face protector or goggles in any situation where skin-eye-
Contact is possible. Prevent contact of refrigerant gas with flame or hot surfaces.
Heat causes refrigerant to break down and form carbonyl chloride (phosgene), a
highly poisonous and corrosive gas.
w. Remove the charging manifold hoses from the air conditioner charging valves.
x. Install service valve protective caps.
y. Using screwdriver, secure charging valve access cover with eight screws.
perform the following steps.
a. Preliminary Procedure. Remove access cover. Except in cases where it is obvious
that the refrigerant charge has been lost, the first step in troubleshooting problems in the
refrigeration system should be to check discharge and suction pressures under operating
conditions. Check pressures as follows:
(1) Turn the mode selector switch to OFF.
(2) Remove service valve access cover. (Refer to Figure 3-4).
