AC-6 AIR CONDITIONING SYSTEM — Troubleshooting 5. REFRIGERANT OVERCHARGE OR INSUFFICIENT COOLING OF CONDENSER Condition: Does not cool sufficiently Symptom seen in refrigeration system | Probable cause | Diagnosis | Remedy Pressure too high at both low and high pressure sides | Unable to develop sufficient performance due to excessive refrigerant in system Condenser cooling insufficient | Excessive refrigerant in cycle → refrigerant overcharged Condenser cooling insufficient → condenser fins clogged or fan motor faulty | (1) Clean condenser (2) Check fan motor operation (3) If (1) and (2) are in normal state, check refrigerant amount Note: Vent out refrigerant through gauge manifold low pressure side by gradually opening valve. 6. EXPANSION VALVE IMPROPERLY MOUNTED/HEAT SENSING TUBE DEFECTIVE (OPENS TOO WIDE) Condition: Insufficient cooling Symptom seen in refrigeration system | Probable cause | Diagnosis | Remedy Pressure too high at both low and high pressure sides Frost or large amount of dew on piping at low pressure side | Defective expansion valve or heat sensing tube not installed correctly Refrigerant flow out of adjustment | Excessive refrigerant in low pressure piping Expansion valve opened too wide | (1) Check heat sensing tube installed condition (2) If (1) is normal, test expansion valve in unit form Replace if defective