EVACUATING THE REFRIGERANT SYSTEM.

TM 5-4120-384-14

5-15. EVACUATING THE REFRIGERANT SYSTEM. - Continued

f. Start vacuum pump.

g. Open charging manifold valves.

h. Open both unit charging valves.

i. Run vacuum pump until at least 29 inches of mercury, measured on gage, is reached.

NOTE

Inability to reach 29 inches of mercury may indicate either a leak or a problem

with the pump.

j. Continue running pump for one more hour, while observing the gage. If gage needle moves back and forth,

you have a leak which must be located and corrected first. (See para 5- 14.)

k. Close charging manifold valves.

Close both unit charging valves.

m. Stop vacuum pump.

n. Disconnect pump from center hose connection.

o. Go to paragraph 5-16, Charging the Refrigerant System.

5-16. CHARGING THE REFRIGERANT SYSTEM.

After the system has been satisfactorily evacuated, it must be fully charged with Refrigerant-22. (See fig. 5-7.)

Never introduce liquid refrigerant into the low pressure (suction) charging valve.

NOTE

The system must be evacuated before charging, Use only Refrigerant-22 to charge

the unit. If available, use recycled refrigerant.

a. On models F18H-3S and F18H-1S the charging operation should be done with all covers in place except for

refrigerant charging valve access cover.

Change 4

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