TM 9-4120-357-14
WARNING
Disconnect power input cable from the air conditioner before doing maintenance work on
the unit. The voltage used can be lethal.
(2) Disconnect all wiring harness plugs from the junction box and control panel assembly. Tie harnesses out of the
way.
(3) Loosen the setscrew in
the end of
core end fitting (14, Figure 4-3) and slide the end fitting off of
cable hold-
down clamp (16) . Remove the cable from hole in top end of actuator arm (15) .
(4) Remove six screws (7) from left side of casing and junction box mounting flange, and two screws (8) and
washers (9) from mounting bracket. Detach the control thermostat sensing bulb and capillary tube from the air condi-
tioner, and carefully coil capillary tube to prevent kinking. Remove the junction box and control panel assembly from the
air conditioner.
b. Discharging the System.
Whenever a
leak is
detected or a
refrigeration component must be
replaced, you must
discharge all gas from the refrigeration system in accordance with paragraph 5-6.
CAUTION
Disconnect power input cable from the air conditioner before doing maintenance work on
the unit. The voltage used can be lethal.
c. Removal.
Connect a
cylinder of
dry nitrogen to
the discharge line service valve, and establish a
1-2 CFM (0.5 -1
M3) flow through the system for 3-5 minutes. Debraze joints of the check valve, and remove it from the system.
d. Installation.
CAUTION
Make sure that the direction-of-flow arrow is pointed toward the pressure relief valve before
brazing the check valve connections. Install the check valve with the direction-of-flow arrow
pointing in the proper direction, and braze connections.
CAUTION
Whenever the refrigeration system has been opened to the atmosphere, you must install a
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 discon-
necting the nitrogen cylinder and the discharge hose.
f. Charging the System. Prepare the refrigeration system for charging by attaching a pressure gage to the high-
pressure service valve gage port, and pressure hose and drier-strainer, loosely, to the suction service valve gage port.
Leave both valves closed. Proceed as follows:
WARNING
Avoid contact with liquid refrigerant or escaping refrigerant gas. Irreversible tissue damage can
result from sudden freezing. Be especially careful to protect the eyes. Avoid inhaling high con-
centration of refrigerant gas, and prevent gas coming into direct contact with flame or hot metal
surfaces; lethal phosgene gas can be formed.
(1) Connect a cylinder of refrigerant, R22, to the pressure hose. Open the cylinder shutoff valve slightly to purge
the hose of air, then tighten the hose connection to the suction service valve gage port.
5-39