TM 9-4120-399-14
5-11. EVACUATING THE REFRIGERANT SYSTEM. (Continued).
a. Check that system was leak tested and it has NO LEAKS. (See para. 5-10).
b. Check that new filter dryer dehydrator was installed. If not, install one.
c. Check that both charging manifold valves are closed.
d. Attach hose assemblies to service valves and charging manifold valves.
e. Attach center hose assembly to vacuum pump.
f. Start vacuum pump.
g. Open charging manifold valves.
h. Run the vacuum pump until at least 29 inches of mercury, measured on the gage, is
reached.
NOTE
Inability to reach 29 inches of mercury may indicate either a leak or a
problem with the pump.
i. Continue running the pump for one more hour, while observing the gage. If the gage
needle moves back and forth, you have a leak which must be located and corrected first.
j. Close charging manifold valves.
k. Stop vacuum pump.
l. Disconnect pump from center hose connection.
5-12. CHARGING THE REFRIGERATION SYSTEM.
WARNING
DANGEROUS CHEMICAL
(R22)
is used in this equipment.
DEATH
or severe injury may result if personnel fail to observe safety precautions.
Use great care to avoid contact with liquid refrigerant gas being discharged
under pressure. Sudden and irreversible tissue damage can result from
freezing. Wear thermal protective gloves and a face protector or goggles
in any situation where skin-eye-contact is possible. Prevent contact of
refrigerant gas with flame or hot surfaces. Heat causes refrigerant to
break down and form carbonyl chloride (phosgene), a highly poisonous
and corrosive gas.