TM 9-4120-357-14
NOTE
If cylinder is equipped with both liquid and gas (vapor) valves,
connect the line to the liquid valve.
2. Weigh the cylinder, and record the weight.
3. Open the discharge line service valve, and slightly open the refrigerant cylinder shutoff valve. Liquid
refrigerant 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.
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.
(e) With power connected to the air conditioner, turn mode selector switch to cool, and turn temperature control
thermostat to maximum decrease position. With compressor operating, observe the sight-glass liquid indicator. If bub-
bles or milkiness appear, top off the refrigerant charge as follows:
1. 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 up-
right, or connect line to the vapor valve.
2. With the air conditioner compressor operating, temporarily prop the front access panel across the
opening. 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.
3. When liquid in sight-glass indicator runs clear and free of bubbles, close the suction line service valve
and the cylinder shutoff valve.
4. Disconnect refrigerant cylinder, and replace caps on both service valves.
g. Final Assembly. Replace panels on the air conditioner as follows:
(1) Position the top panel on the air conditioner, and secure with 31 screws and washers.
(2) Position front access panel on unit by placing lower edge behind the step of the base plate. Push into contact
with the casing, and secure with four panel fastener screws.
5-19. Drier-Strainer (Dehydrator).
a. Access. Obtain access to the drier-strainer in accordance with the following procedure:
(1) Unscrew four panel fastener screws from the front access panel. Remove the panel.
WARNING
Disconnect power input cable from the air conditioner before doing
maintenance work on the unit. The voltage used can be lethal.
(2) Disconnect wiring harness plugs from all receptacles on the junction box and control panel assembly.
(3) Disconnect the circuit breaker operating cable as follows:
(a) Loosen the setscrew in the end of the core end fitting (14, Figure 4-3) and slide the fitting off the cable
core.
5-29
