TM 9-4120-357-14
(8) Connect a cylinder of refrigerant, R22, loosely to the discharge line service valve, and open the cylinder shut-
off valve for a few seconds to purge the line of air. Tighten the service-valve connection. Charge the refrigeration sys-
tem as directed in the following steps:
(a) Place the refrigerant cylinder on a scale of sufficient capacity, with the shutoff valve down, or suspend the
cylinder from a spring scale or beam scale, with the valve end down.
NOTE
If cylinder is equipped with both liquid and gas (vapor) valves, connect
the line to the liquid valve.
(b) Weigh the cylinder, and record the weight.
(c) Open the discharge line service valve, and slightly open the refrigerant cylinder shutoff valve. Liquid re-
frigerant will be sucked into the refrigeration system rapidly at first, then more slowly as pressures begin to equalize.
When 25 pounds (11.4 KG) of refrigerant have flowed into the refrigeration system as indicated by the scale, close the
discharge line service valve and the cylinder shutoff valve.
h. Reassembly. After charging the refrigeration system with a basic quantity of refrigerant as above, the air condi-
tioner must be returned to operating condition for final checking. Proceed as follows:
(1) Position the junction box and control panel assembly in the air conditioner, and secure with six screws (7, Fig-
ure 4-3) through the left side of the casing, and two screws (8) and washer (9) through the lower right mounting bracket.
(2 ) Carefully lead thermostat sensing bulb and capillary tube around condenser coil to
position in
middle of
(3) Insert the core of the flexible cable assembly (17) through the hole in the top of the circuit breaker actuating
arm (15). Install the core end fitting (14), and tighten setscrew.
(4) Connect all electrical harnesses to
the junction box, control panel and compressor. Temporarily prop front ac-
cess panel across opening.
i. Operating check.
WARNING
Hearing protection must be worn when maintenance is performed
while air conditioner is in operation. Failure to heed this warning
can result in hearing loss or injury.
CAUTION
Connect power to unit as soon as possible after charging or any
period when power has been disconnected. Allow heater time to
vaporize refrigerant in compressor before operation in COOL
mode. If knocking or pounding is heard at start of COOL mode,
turn selector switch to OFF or VENTILATE at once and allow addi-
tional warm up time.
(1) With power connected to the air conditioner, turn the mode selector switch to cool. Turn the temperature con-
trol thermostat to maximum decrease position. With the compressor operating, observe the sight-glass liquid indicator.
If bubbles or milkiness appear, top off the refrigerant charge as follows:
(a) Connect a cylinder of refrigerant, R22, loosely to the gage port of the suction line service valve. Open the
cylinder shutoff valve for a few seconds to purge air from the line. Tighten the connection. Leave the cylinder upright, or
connect line to vapor valve.
(b) With the air conditioner compressor operating, open the suction line service valve and the cylinder shutoff
valve to charge refrigerant gas into the system, while observing the sight-glass liquid indicator.
(c) When the liquid in the sight-glass indicator runs clear and free of bubbles, close the suction line service
valve and the cylinder shutoff valve.
(d) Disconnect the refrigerant cylinder, and replace caps on both service valves..
(2) Replace the front access panel on air conditioner, and secure with four panel fastener screws.
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