TM 9-4120-404-14
4-6. SERVICING THE REFRIGERANT SYSTEM. - Continued.
f. Charging the System .
(1) Recover refrigerant from system per step b.
(2) Remove safety cap from R-22 refrigerant cylinder.
(3) Attach refrigerant cylinder to manifold.
(4) Open high pressure and low pressure service valves.
(5) Close the low pressure (suction) charging manifold valve.
(6) 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).
(7) Open the refrigerant 22 cylinder valve.
(8) Allow liquid refrigerant to enter the system until the cylinder weight has decreased by 11.0 pounds (4.9 kg)
or until system pressure has equalized.
(9) Close the refrigerant cylinder valve and the high pressure (discharge) manifold valve.
(10) Connect power.
(11) Be sure circuit breakers are on.
(12) Press and release both pressure switch reset buttons.
(13) Turn air conditioner on and operat e in the COOL mode with the temperature control thermostat set at a
maximum COOL position.
(14) If the 11.0 pound (4.9 kg) full charge was obtained, skip steps (15) through (17). If the system pressure
equalized prior to obtaining a full charge of 11.0 pounds (5.0 kg), proceed with step (18).
(15) Switch the refrigerant cylinder to the gas only position.
(16) Be sure that the refrigerant cylinder has been switched to the gas position and open the refrigerant cylinder
valve and the low (suction) pressure charging manifold valve.
(17) Monitor the weight of the refrigerant cylinder as the air conditioner compressor pulls additional refrigerant
gas into the system until the full 11.0 pound (4.9 kg) charge is obtained. When the system is fully charged, immediately
close the refrigerant cylinder valve.
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