PRESSURE TESTING THE REFRIGERANT SYSTEM.

TM 5-4120-369-14

PRESSURE TESTING THE REFRIGERANT SYSTEM.

a. General. A pressure test will indicate whether the air conditioner is operating at normal or at abnormal pres-

sures. When the air conditioner is not operating at normal pressures, the cause should be ascertained and corrected. Refer to

Table 5-1 for troubleshooting chart.

System Pressure Test. Remove caps from high and low pressure service valves (Figure 5-6), connect suction and

discharge pressure gages to their respective service valves. Compare the gage reading with the normal range of system pressure

SERVICING REFRIGERANT SYSTEM.

Caution should be exercised with fluorocarbon refrigerant gas as

they can displace oxygen and thereby cause suffocation.

Personnel with a history or other evidence of cardiac rhythm

abnormalities should be made aware of the potential for aggrava-

tion of existing cardiac rhythm abnormalities or the induction of

arrhythmias, as a result of exposure to fluorocarbon refrigerant

gases. Such individuals should be evaluated by local medical

authorities before working in environments where potential

refrigerant gas exposure may occur.

a. General. When the air conditioner must undergo maintenance that requires opening the system, the system

must be discharged with a Recovery/Recycling Unit prior to maintenance, then leak tested and purged, a new dehydrator

installed (paragraph 5-20), and the system charged after maintenance. Basic procedures involved in servicing the refrigerant

system are as follows:

(1) Discharging System. Refer to Figure 6-1 and proceed as follows to discharge the refrigerant system:

Avoid bodily contact with liquid refrigerant and avoid inhaling

refrigerant gas. Be especially careful that refrigerant 22 does not

come in contact with eyes. In case of refrigerant leaks, ventilate

area immediately.

Remove access cover.

Step 1

Step 2

Remove Low Pressure charging valve cap. Attach a suitable hose to

charging valve.

NOTE

In accordance with Environmental Protection Agency regulations,

refrigerants cannot be discharged into the atmosphere. A refriger-

ant recovery & recycling unit must be used whenever discharging

the refrigerant system.

Operation of the recovery/recycling unit must be by AUTHO-

RIZED PERSONNEL ONLY

Step 3 Connect and operate a recovery/recycling unit in accordance with the

manufactuere's instructions.

(2) Testing System for Leaks. Refer to paragraph 5-6 and leak test the refrigeration system.

Change 2

6-2