1855 / 1906
HVAC
41
5
Expansion valve mal-
functioning (opening
too much) and improp-
er installation of heat
sensitizing tube.
Air conditioner does not cool effectively.
Symptoms in refrigerant cycle
Pressure on both the low and high.
pressure sides is high.
Frost or heavy dew is formed on the
piping on the low pressure side.
Cause
The expansion valve is malfunctioning
or the heat sensitizing tube is improper-
ly installed.
Flow control is not properly performed
Diagnosis
Excessive liquid refrigerant in the low
pressure side piping.
Expansion valve opened too far.
Countermeasures
Check the installation of the
heat sensitizing tube.
If the installation is proper,
replace the expansion valve.
6
Faulty compression of
compressor
Condition
Air conditioner does not cool. Symp-
toms in refrigerant cycle.
Pressure on the low pressure sides is
too high and pressure on the high pres-
sure side is too low.
Cause
There is leaking in the compressor .
Diagnosis
Faulty compression of compressor.
Delivery valve or packing is leaking or
broken or compressor is malfunction-
ing.
Countermeasures
Check the compressor oil for
contamination and quantity.
Replace the compressor.