is a schematic flow diagram
of the refrigeration
system in the air
f. REFRIGERATION SYSTEM.
Conditioner. Operation is as follows
(1) COMPRESSOR. Low-pressure, low temperature refrigerant vapor is drawn into the hermetically-sealed
motor-compressor unit through the low pressure line from the accumulator. Refrigerant enters the compressor unit into the
shell near the top, is circulated around and through the motor, and enters the compressor. From the compressor, the refrigerant
under high pressure is delivered to the condenser. During compressor motor rotation, grooves in the crankshaft carry oil from
(2) CONDENSER. From the compressor, refrigerant gas enters the condenser at a pressure sufficient to raise its
condensation temperature above that of the ambient air. Thus, as the airflow across the condenser coil extracts heat from it the
refrigerant condenses to a liquid and settles to the bottom level of the condenser coil.
(3) LIQUID LINE COMPONENTS. From the condenser, liquid refrigerant passes through a filter-drier and a
sight glass. A drying chemical in the filter-drier absorbs moisture, acids, and other liquid contaminants, and a filter captures
and retains solid contaminants. The sight glass provides visible indication of the fluid state of the refrigerant. Refrigerant
passing through the sight glass should be in the form of a clear liquid. Bubbles in the sight glass are an indication of a shortage
of refrigerant in the system. Also in the liquid line are: a charging valve for adding liquid refrigerant a cutout that switches off
the electrical circuit when the refrigerant pressure becomes excessive and a plug containing a fusible metal that melts when the
liquid refrigerant becomes overheated, allowing refrigerant to escape.