TM 9-4120-357-14
(2) Connect lead A of the wiring harness (6) to terminal 1 of low-pressure cutout switch (4), and lead B to terminal
2 of high-pressure cutout switch (1). Position insulating caps (2) on both switches, and secure with spring clips (3).
CAUTION
When handling capillary tubes, be extremely careful to avoid sharp
bends or kinks.
(3) Place a split grommet (8) over each capillary tube, and install switches in housing (7). Press grooves of
grommets into notches in walls of housing. Secure switches with four screws and washers.
e. Installation. Install the pressure cutout switch assembly in the air conditioner as directed in the following
procedure:
(1) With the help of an assistant, position the switch assembly against the inside of the rear panel, and install four
screws and washers.
(2) Connect plug, P16, to receptacle, J16, on top of pressure cutout switch housing.
(3) Carefully lead capillary tube connection of
high-pressure cutout switch to
the fitting on
the compressor dis-
charge line and the low-pressure capillary tube connection to the fitting on the compressor suction line.
(4) Tighten flare nuts, and coil the surplus capillary tubing out of the way. Tape tubing to adjacent refrigerant pip-
ing for support.
f. Testing for Leaks. Whenever a component of the refrigeration system has been replaced, you must test the
system for refrigerant leaks. Three methods are available for detecting leaks; the electronic leak detector, the Halide
torch, and the soap bubble method. The preferred method is the electronic leak detector.
Use GE type H10 elec-
tronic leak detector or equivalent.
CAUTION
The electronic and Halide torch leak detectors are sensitive to the
presence of refrigerant gas in the atmosphere. When refrigerant
gas is present in the atmosphere of the work area, false indications
can result. Use in a well ventilated but draft-free area.
(1) Electronic Leak Detector. Turn the electronic unit on, and slowly pass the probe around all points
of the refrigeration system at which a leak could exist. Depending upon the type of detector used, a leak will be indicated
by an audible signal, a light, or by meter deflections.
(2) Halide Torch. Turn on the gas from the cylinder and light the torch. Adjust to obtain a stable light-
blue flame. Pass the open end of the sensing tube slowly around all locations at which a leak could exist. A small leak
will be indicated by the flame turning from blue to green. A large leak will be indicated by the flame turning from blue to
indigo with a red tip, or the torch may be extinguished.
(3) Soap Solution. Brush soap solution on all possible points of leakage, and watch for bubbles. Fol-
low a definite sequence to avoid missing any points that should be tested. Wipe the solution from all joints, and mark
any point at which a leak is found.
CAUTION
Whenever the refrigeration system has been opened to the atmos-
phere, you must install a new drier-strainer (dehydrator) before
With the refrigeration system discharged and a hose attached to the gage port of the suction service valve, connect a
cylinder of oil-pumped dry nitrogen to the gage port of the high-pressure service valve. Open the high-pressure service
valve, and crack open the cylinder shutoff valve to establish a flow of 1-2 CFM (0.5 -1 M3) through the system. Purge for
at least 30 minutes to expel all other gases, impurities and water vapor. Turn off both service valves before disconnect-
ing the nitrogen cylinder and the discharge hose.
5-21