TM9-4120-400-14
(See fig. 2-2.) The refrigerant sight glass is the only visual indicator incorporated in the Model F9000H-3SA, and
F9000H-1SA air conditioners. 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 conditioner is in operation in the COOL mode. The unit must be operated approximately 15 minutes at
maximum cooling prior to checking condition of refrigerant at sight glass. 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 level becomes unacceptable. Excessive moisture in the
refrigerant may damage or possibly destroy the compressor. If the liquid refrigerant observed in the sight glass has
a 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 refrigeration system action.
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.
Section II OPERATOR PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)
GENERAL.
Preventive maintenance checks and services (PMCS) are essential to the efficient operation of the air conditioner
and to prevent possible damage that might occur through neglect or failure to observe warning symptoms in a
timely manner. Checks and services performed by operators are limited to those functions which can be
accomplished from the outside of the cabinet. The Preventive Maintenance Checks and Services table lists the
inspections and care of the air conditioner required to keep it in good operating condition.
a. Before You Operate. Always keep in mind and observe the WARNINGS and CAUTIONS contained in this
technical manual and plates installed on the equipment that are associated with the functions you are about to
perform. Perform your before (B) PMCS from Table 2-1.
b. While You Operate. Always keep in mind and observe the WARNINGS and CAUTIONS contained in this
technical manual and plates installed on the equipment that are associated with operational functions. Perform
c. After You Operate. Be sure to perform your after (A) PMCS from Table 2-1.
d. If Your Equipment Fails to Operate. Troubleshoot within your capabilities and with proper equipment,
Report any deficiencies using the proper forms, See DA Pam 738-750.
e. Service Intervals. The interval column of the PMCS table tells when to do a certain check or service.
f. Procedure Column. The procedure column of the PMCS table tells how to do the required check and
service.
g. Reporting and Correcting Deficiencies. If the air conditioner does not perform as required, refer to Chapter
3 under Troubleshooting for possible problems. Report any malfunctions or
failures on DA
Form 2404, or
refer to
DA Form 738-750.