TM 9-4120-357-14
b. Replacement of crankcase heater. Replace the crankcase heater as
follows:
(2) Remove the retaining spring (8) from the hooked ends of
the heating element (7), and spring the ends apart
just enough to work the heater off the compressor housing to remove.
(3) Carefully spread the replacement heating element (7) just enough to
work it
around the compressor housing.
Retain by hooking the spring (8) over both ends of the heating element.
(4) Connect lead wires to terminal.
c. Assembly. Assemble the air conditioner in the following manner:
(1) Install electrical receptacle (6, figure 4-12) in
the flage of
the compressor junction box, and secure it
with four
screws, lock washers, and nuts.
(2) Place the junction box cover (4) on
the compressor, and secure it
with wing nut and washer.
(3) Connect plug, Pll11, to receptacle, J 1.
(4) Install the front access cover on the air conditioner by placing the lower edge of the cover behind the step in
the base plate, and pushing into position. Secure with four panel fastener screws.
Section XI. MAINTENANCE OF PRESSURE CUTOUT SWITCHES
4-34. General.
The high- and low-pressure cutout switches are operated by internal pressure of the refrigeration system, and serve
to protect the air conditioner from extremes of pressure. No conclusive test can be performed without opening the refrig-
eration system. If either high- or low-pressure cutout switch trip off frequently, of if resetting them does not restore nor-
mal operation, check for electrical operation as follows:
Place a yoke type ammeter on the power supply cable, and turn the selector switch to cool and the temperature con-
trol thermostat to maximum decrease. While observing the ammether, press one pressure cutout switch reset button,
then release. Repeat with the other reset button. If the switches are electrically ok, the ammeter will indicate a lower
amperage when each reset button is pressed, and will return to its original indication when each button is released. If the
trouble persists, report it to direct support maintenance.
Section XII. MAINTENANCE OF REFRIGERATION COMPONENTS
4-35. General.
Only maintenance of refrigeration components which can be performed without opening the refrigeration system is
coils are included.
4-36. Solenoid Valves.
The two solenoid valves, K3 and K4, are identical. Coil replacement procedure is the same for both.
a. Access. Solenoid valve, K3, is
located between the compressor and the junction box in
the lower part of
the air
conditioner. Valve, K4, in the bypass circuit is located about halfway between the two reservoir tanks behind the evapo-
rator air intake grille. To obtain access to K3, unscrew four panel fastener screws from the front access panel, and re-
move panel. To obtain access to K4, remove 12 screws and washers from each evaporator air intake grille ant remove
both grilles.
4-43