TM 9-412039914
512.
CHARGING
THE
REFRIGERATION
SYSTEM.
(Continued).
e. Open the refrigerant 22 cylinder valve slightly to allow a small amount of
refrigerant to purge air from the hoses. Tighten the hose connections at the air conditioner
charging valves.
f. Close the low pressure (suction) charging manifold valve. Never introduce liquid
refrigerant into the low pressure (suction) charging valve.
g. Position the refrigerant 22 cylinder so that liquid will be used for charging. (Some
cylinders must be inverted and some are equipped with a selector valve).
h. Open the refrigerant 22 cylinder valve.
i. Allow liquid refrigerant to enter the system until the cylinder weight has decreased
by 8.0 pounds (3.6 kg) or until system pressure has equalized.
j. Close the refrigerant cylinder valve and the high pressure (discharge) manifold
valve.
k . Connect power.
l. Be sure circuit breakers are on.
m. Press and release both pressure switch reset buttons.
n. Turn air conditioner on and operate in the COOL mode with the temperature
control thermostat set at a maximum DECREASE position. 9-0.6
o. If the 8.0 pound (3.6 kg) full charge was obtained, skip p. thru r. If the system
pressure equalized prior to obtaining a full charge of 8.0 pounds (3.6 kg), proceed with step q.
p. Switch the refrigerant cylinder to the gas only position.
q. Be sure that the refrigerant cylinder has been switched to the gas position and
open the refrigerant drum valve and the low (suction) pressure charging manifold valve.
r.
Monitor the weight of the refrigerant cylinder as the air conditioner compressor
pulls additional refrigerant gas into the system until the full 8.0 pound (3.6 kg) charge is obtained.
When the system is fully charged, immediately close the refrigerant cylinder valve.
s.
Run the air conditioner in COOL mode (with temperature control thermostat in
full COOLER position for 15 minutes.
CAUTION
Do not skip the next step.
t. After 15 minutes, observe the sight glass on back of condenser section. Green
center means the refrigerant moisture content is acceptable. Yellow center means there is too
much moisture in the system. It must be discharged, evacuated, and charged again.
518
CHANGE 1
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