Figure 2-2. Control Module

TM5-4120-347-14

The refrigerant sight glass is the only visual indicator incorporated in the Model F9000H-3 Air Conditioner.

The refrigerant sight glass has a small chamber with a glass window through which the refrigerant condition

can be observed. It is installed in the liquid refrigerant line downstream from the condenser coil. Liquid

refrigerant actually flows through the sight glass chamber only during cooling cycles when the air condition

is in operation in the COOL mode. The sight glass is equipped with a center indicator that is moisture sensitive.

Dry refrigerant is indicated by green, it turns to chartreuse when the moisture content becomes undesirable,

and to yellow when the Ievel becomes unacceptable. Excessive moisture in the refrigerant may damage or

possibly destroy the compressor. If the liquid refrigerant observed in the sight glass has an opaque, milky

appearance, or frequent bubbles appear, the volume of refrigerant is low and the system should be charged.

Either moisture or low charge indications should be reported to direct support maintenance for appropriate

Do not operate the air conditioner in the COOL mode if the refrigerant color has reached the yellow

band or if numerous bubbles appear in the sight glass. COOL mode operation may be continued with

the refrigerant color in the chartreuse band or with only an occasional bubble appearing in the

window, but the sight glass should be rechecked after each four hours of operation to Insure that the

condition has not become worse.

2-3