TM9-4120-400-14
5-16.
CHARGING THE REFRIGERANT SYSTEM. - continued
10. With unit running, observe sight glass on back of condenser section. Be sure that the refrigeration system is
not in bypass. When system goes into bypass bubbles will appear in the sight glass.
Green center means refrigerant moisture content is acceptable.
Yellow center means there is too much moisture in system. It must be discharged, evacuated, and
charged again.
Milky white or bubbly liquid means system has a low charge.
Clean bubble-free liquid around center means the system is fully charged.
11. If charge is still low, carefully add refrigerant.
Never introduce liquid refrigerant into the low pressure (suction) charging valve. This can
a.
Set refrigerant cylinder to deliver gas only.
Never introduce high discharge pressure into a refrigerant cylinder. This can cause the
cylinder to rupture and injure personnel.
b.
Check that pressure gauge valve is closed.
c.
Open compound gauge and charge valves.
d.
Continue to charge until sight glass is clear and bubble-free.
e. Close compound gauge, charge, and refrigerant cylinder valves.
12. Turn MODE SELECTOR switch to OFF.
NOTE
FOLLOW-ON MAINTENANCE:
5-46