SAFARI STORME MY14

HVAC 43 HVAC REFRIGERATION CYCLE TROUBLESHOOTING Sr. No. Possible Cause Remedy 3 Entry of moisture in the refrigerant cycle Condition x Air conditioner alternately cools and does not cool. Symptoms in refrigerant cycle x During operation, the pressure on the low pressure side alternates between vacuum and normal. Cause x The moisture mixed in the refrigerant in the refrigerating cycle freezes in the expansion valve orifice, blocking the cycle. After a time, the ice melts and normal conditions return Diagnosis x The drier is in an oversaturated condi- tion. x The moisture in the refrigerating cycle freezes the expansion valve orifice, impeding refrigerant circulation. Countermeasures x Remove the moisture by repeated evacuation. x Recharge new refrigerant to the specified amount. 4 Refrigerant fails to circulate Condition x Air conditioner does not cool. Symptoms in refrigerant cycle x Pressure on the low pressure side is vacuum x Pressure on the low pressure side is vacuum low. x Frost or dew is formed on the piping at the front and rear side of the re- ceiver or the expansion valve. Cause x Moisture or dirt in the refrigerating cycle freezes or sticks to the expan- sion valve orifice, obstructing refrigerant flow. x Gas leaking from the heat sensitizing tube of the expansion valve obstructs refrigerant flow. Diagnosis x Blocked expansion valve orifice. Countermeasures x Allow to stand for some time and then resume op- eration to decide whether the blockage is caused by moisture or by dirt. If caused by moisture; re- move the moisture by evacuation, Recharge new refrigerant to the specified amount. x If cased by dirt; remove the expansion valve and blow out the dirt with com- pressed air. If unable to remove the dirt, replace the expansion valve. Evacuate and charge new refrigerant to the specified amount. If caused by gas leaking from heat sensitiz- ing tube, replace the expansion valve.