Page text (OCR transcript)
AC–72
AIR CONDITIONING SYSTEM – TROUBLESHOOTING
2. MOISTURE PRESENT IN REFRIGERATION SYSTEM
Condition: Periodically cools and then fails to cool
N04145
Symptom seen in refrigeration system | Probable cause | Diagnosis | Remedy
• During operation, pressure on low pressure side sometimes becomes a vacuum and sometimes normal
• Moisture entered in refrigeration system freezes at expansion valve orifice and temporarily stops cycle, but normal state is restored after a time when the ice melts
• Drier in oversaturated state
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• Moisture in refrigeration system freezes at expansion valve orifice and blocks circulation of refrigerant
(1) Replace receiver/drier
(2) Remove moisture in cycle through repeatedly evacuating air
(3) Charge new refrigerant to proper amount
3. INSUFFICIENT REFRIGERANT
Condition: insufficient cooling
N04148
Symptom seen in refrigeration system | Probable cause | Diagnosis | Remedy
• Pressure low on both low and high pressure sides
• Bubbles seen in sight glass continuously
• insufficient cooling performance
• Gas leakage at some place in refrigeration system
• Insufficient refrigerant in system
• Refrigerant leaking
(1) Check for gas leakage with leak detector and repair if necessary
(2) Charge refrigerant to proper amount
(3) If pressure indicated value is near 0 when connected to gauge, create the vacuum after inspecting and repairing the location of the leak
