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REFRIGERATION SYSTEM TROUBLESHOOTING.
This task covers:
Unit operating in full COOL.
(1) Check sight glass condition.
(a) A bright green color indicates that the refrigerant is dry. As moisture content increases, the color will
gradually change from chartreuse until it reaches pure yellow. A gradual change from green into
chartreuse over an extended period of time is normally an indication that the refrigerant desiccant
dehydrator is becoming saturated with moisture. If so, replace. A sudden change of color is highly
unlikely unless a rupture occurs allowing all refrigerant to escape.
Be sure that the refrigeration system is under full load with the compressor
running when observing the sight glass for refrigerant condition.
(b) The appearance of an occasional bubble in the sight glass can be expected, especially when
operating in a high ambient temperature. A gradual increase in the number and frequency of
bubbles is usually an indication that the refrigerant charge is being lost from the system through a
small leak. The number and frequency of bubbles will also increase if the refrigeration system
becomes overheated. The sudden appearance of numerous bubbles is usually an indication of a
(2) Check for decreased cooling capacity.
A reduction in cooling capacity will occur as a natural result if refrigerant is lost from the system; with a total
loss of cooling if all refrigerant is lost. However, in some conditions a considerable proportion of the
refrigerant may be lost before the reduced cooling capacity is noticeable. Sudden or erratic reduction, or
complete loss of cooling capacity is often caused by the malfunction of one of the valves in the
refrigeration system. Cooling capacity will also be reduced if the refrigeration system becomes
(3) Turn rotary MODE selector switch to OFF/RESET.