Section I. DESCRIPTION AND USE OF OPERATOR'S CONTROLS AND INDICATORS
The model AH-54 Air Conditioner is designed for a variety of installations and for operation under a
wide range of climatic conditions. It is also designed for continuous or intermittent operation. Operators must be aware of any
peculiarities or operational limitations for their specific installation. See the appropriate shelter or system manual for
instructions peculiar to your specific installation.
See figure 2-1 for
a general description
of the controls that
an operator will
normally be concerned with. For specific operating instructions, see Sections III and IV of this chapter.
The refrigerant sight glass (fig. 12, item 4) is the only visual indicator used on the air
conditioner. The sight glass is a port or window through which the refrigerant condition can be seen. Liquid refrigerant actually
flows through the sight glass chamber only during cooling cycles. The unit must be operated approximately 15 minutes in
maximum cooling prior to checking condition of refrigerant at sight glass. 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 your supervisor.
Do not operate the air conditioner in the cooling mode if numerous bubbles appear in the sight glass.
Cooling operation may be continued with only an occasional bubble appearing in the window, but the
sight glass should be rechecked after each four hours of operation to ensure that the condition has not
Section II. OPERATOR PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)
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 are described in table 2-1.
a. Before You Operate. Always keep in mind and observe the WARNINGS and CAUTIONS. Perform your before (B)