TM 9-4120-378-14
5.9 REFRIGERATION SYSTEM SERVICING - (CHARGING). - Continued
Remarks
Action
Location/Item
Open the refrigerant cylinder valve, the low (suc-
q.
tion) pressure charging manifold valve, and the low
(suction) pressure service valve on the air condi-
tioner.
Monitor the weight of the refrigerant cylinder as the
r.
air conditioner compressor pulls additional refriger-
ant gas into the system until the full 2.875 Ibs (1 .15
kg) charge is obtained. When the system is fully
charged, immediately close the refrigerant cylinder
valve.
Run the air conditioner in COOL mode with temper-
s.
ature control thermostat in full COOLER position
for 15 minutes.
NOTE
Do not skip the next step.
t . After 15 minutes, observe the liquid sight indicator
(sight glass) on left rear of unit.
Green center means the refrigerant moisture con-
tent is acceptable.
Yellow center means there is too much moisture in
the system. It must be discharged, evacuated and
charged again.
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.
If charge is low, add gas refrigerant.
u.
Switch refrigerant cylinder to vapor position. Open
cylinder valve and the manifold low pressure valve.
Check air conditioner for proper cooling. There
v.
should beat least a 5 F temperature difference be-
tween evaporator discharge air and inlet air. Turn
Mode Selector switch to OFF.
w. Close the high and low pressure service valves and
remove charging manifold hoses.
5-27
