Carrier PrimeLINE 69NT40-561, Inspection Manual

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Figure 24 PTI Tests
10. Check the unit’s TXV and EEV superheat setting. Consult the
operation & service manual for the correct superheat setting and
procedure. Valve settings should not be adjusted if incorrect superheat
is observed then the valve or sensors must be replaced.
Note : For
PrimeLINE units, the superheat can be observed at code 54.
11. Check filter drier operation by monitoring the temperature
difference across the drier. Excessive temperature drop across the
drier or frosting indicates a restriction in the filter and the filter
should be replaced.
12. Check for proper color of moisture/liquid indicator (Refer to Figure
25 ). If moisture is indicated:
a. Evacuate and dehydrate the system.
b. Replace the unit filter drier.
c. Use Total Test kit to determine if acid or moisture remains in
the system.