RJ150-30 / Operations and Maintenance Manual
Mobile Aircraft Air Conditioner
Trailer Mounted, Cool Mode Only
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SECTION 2 - 1
JANUARY 20, 2004
PAGE 18
(10) Tip the refrigerant cylinder so that the outlet valve is at the lowest point
allowing liquid refrigerant to flow through the charging hose.
(11) Start the unit and operate the compressor in COOL mode. (Refer to
Section 1-2) The tubing connecting the refrigerant cylinder to the charging
valve is not of sufficient size to supply enough refrigerant to prevent the
system from pumping down into a vacuum. Watch the suction gauge and
do not allow suction pressure to go below zero ("0") psig. The ideal
pumping is to approach a vacuum without actually pumping into a
vacuum.
(12) If the system has lost its charge completely, charge only the specified
weight of the refrigerant into the system. DO NOT OVERCHARGE.
Check that the refrigerant charge is free from bubbles and completely fills
the sight gauge.
(13) If the system has a partial charge, charge the system with only three (3)
pounds (1.4 kg) of refrigerant at a time. Stop the charging process and
operate the unit in COOL mode. (Refer to Section 1-2) Observe the
refrigerant charge in the sight glass as stated above. Repeat the
procedure until the correct refrigerant charge is obtained without
overcharging.
G. Refrigerant Leak Testing:
WARNING
WEAR PROPER EYE PROTECTION (GOGGLES) WHEN WORKING WITH
REFRIGERANTS. CONTACT WITH REFRIGERANT MAY CAUSE INJURY.
Refrigerant loss results in reduced system efficiency and capacity and may
cause repeated activation of system safety monitors resulting in unit
shutdown. Leak testing should be accomplished at scheduled intervals (Refer
to Table 2) and after any work has been accomplished on the unit.
(1) Testing Methods:
(a) Fluorescent Dye Detector:
The unit is charged with fluorescent dye, which may be observed when
illuminated with a black light detector. Follow manufacturer's
instructions as required.
(b) Electronic Leak Detector:
A detecting probe is passed over the area of a suspected leak. If a leak
is present, the detector provides and audible and/or visual indication.
Follow manufacturer's instructions as required.
(c) Soap Bubble Testing:
Apply a generous amount of common dish washing detergent to
suspected areas. A large leak present will create telltale bubbles in the
detergent.
