
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