TM 9-4120-402-14
5-17. CHARGING THE REFRIGERANT SYSTEM. - continued
(9)
Turn air conditioner on and operate in COOL mode with potentiometer TEMPERATURE control set at
maximum COOL position.
(10) With unit running, observe sight glass on back of condenser section. Be sure that the compressor is
running.
(a)
Green center means refrigerant moisture content is acceptable.
(b)
Yellow center means there is too much moisture in system. It must be discharged, evacuated,
and charged again.
(c)
Milky white or bubbly liquid means system has a low charge.
(d)
Clean bubble-free liquid around center means the system is fully charged.
CAUTION
Never introduce liquid refrigerant into the low pressure (suction) charging valve. This can cause
damage to the compressor.
(11) If charge is low, carefully add refrigerant.
(12) Set refrigerant cylinder to deliver gas only.
WARNING
Never introduce high discharge pressure into a refrigerant cylinder. This can cause the cylinder
to rupture and injure personnel.
(13) Check that pressure gauge valve is closed.
(14) Open compound gauge and charge valves.
(15) Continue to charge until sight glass remains clear and bubble-free for 15 minutes.
(16) Close compound gauge, charge, and refrigerant cylinder valves .
(17) Turn rotary MODE selector switch to OFF/RESET.
NOTE
FOLLOW-ON MAINTENANCE:
Remove service manifold (para 5-10).
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