TM 9-4120-357-14
1. Place the refrigeration 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 liq-
uid 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 refriger-
ant will be sucked into the refrigeration system rapidly at first, then more slowly as pressure begin to equalize. When 25
pounds (11.4KG) of refrigerant have flowed into the refrigeration system, as indicated by the scale, close the discharge
line service valve and the cylinder shutoff valve.
g. Assembly and Operating Test. The junction box and control panel assembly must be installed so that the air
conditioner can be operated for testing. Proceed as follows:
(1) Position the junction box and control panel assembly in the air conditioner, and secure with six screws (7,
Figure 4-3) through the casing into the mounting flange, and two screws (8) and washers (9) through the mounting
bracket.
(2) Carefully lead control thermostat sensor bulb and capillary tube around condenser coil to middle of evaporator
intake chamber. Install bulb in loop clamp.
(3) Install the circuit breaker operating cable as follows:
(a) Insert the end of the flexible cable core through the hole in the top of the actuator arm (15, Figure 4-3) .
Slide the core end fitting (14) over cable core, and tighten the setscrew temporarily.
(b) Place the hold-down clamp (16) over the cable (17) , and attach it to the junction box with two screws
and washers.
(c) Adjust the core end fitting to provide 0.120 - 0.250 inch (3-6MM) clearance below the actuator arm when
the cable is fully extended and the circuit breaker turned off.
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 opera-
tion in COOL mode. If knocking or pounding is heard at start of COOL mode, turn selec-
tor switch to OFF or VENTILATE at once and allow additional warm up time.
(4) With power connected to the air conditioner, turn the mode selector switch to cool, and turn the temperature
control thermostat to maximum decrease position. Temporarily prop the front access panel across the opening. 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, and
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 shut-
off valve to charge refrigerant gas into the system, while observing the sight-glass liquid indicator.
(c) When 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.
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