EXPANSION VALVE. - TM-5-4120-339-140100

TM 5-4120-339-14

d. Installation.

(1) Refer to figure 4-11 and install the suction pressure service valve and/or the discharge pressure service

valve.

(2) Perform any further maintenance of refrigeration components required.

(3) If no further maintenance of refrigeration components is required, refer to paragraph 4-8 and purge the

refrigerant system.

(4) Refer to paragraph 4-4c and check the service valves and the dehydrator for refrigerant leaks. Refer to

paragraph 4-4d and repair any leaks found.

(5) Refer to figure 4-4 and evacuate the refrigerant system.

(6) Refer to paragraph 4-10 and charge the system with refrigerant.

(7) Re-perform inspection procedure (paragraph a) for service valve to check for refrigerant leaks.

4-15.

EXPANSION VALVE.

a. Inspection.

(1) Turn the selector switch to the "OFF" position and disconnect the air conditioner from the electrical power

source.

(2) Refer to figure 4-12 and inspect the expansion valve, power bulb and tubing for obvious defects.

(3) Refer to paragraph 4-4c and check the expansion valve for refrigerant leaks. If expansion valve is leaking

refrigerant, refer to step c for repair.

b. Adjust.

CAUTION

Never adjust the expansion valve unless absolutely necessary. When adjusting

the expansion valve, allow the unit to run on "COOL" at least 20 minutes between

each adjustment. Insure that all panels are in place during the running period.

(1) Refer to figure 4-12 and tape the bulb of a thermometer to the suction line near the expansion valve

power bulb.

(2) Refer to figure 4-5 and install a suction pressure gage.

(3) Turn the selector switch to the "COOL" position and turn the thermostat control knob counter-clockwise to

its limit. Operate the unit on cool for approximately 30 minutes to stabilize the thermometer reading.

(4) Note pressure indicated on the suction pressure gage. To this pressure, add 2 psig (the estimated

suction line loss).

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