TIAGO

HVAC 39 REFRIGERATION CYCLE TROUBLESHOOTING Sr. No. POSSIBLE CAUSE REMEDY 5 Expansion valve malfunctioning (opening too much) and improper instal- lation of heat sensitizing tube. Condition  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 quan- tity.  Replace the compressor.