13.2. Relationship between the condition of the air conditioner and
pressure and electric current
Condition of the air
conditioner
Insufficient refrigerant (gas
leakage)
Clogged capillary tube or
Strainer
Short circuit in the indoor unit
Heat radiation deficiency of
the outdoor unit
Inefficient compression
• Carry out the measurements of pressure, electric current, and temperature fifteen minutes after an operation is started.
13.3. Diagnosis methods of a malfunction of a compressor
Nature of fault
Insufficient compressing of a compressor
Locked compressor
Low Pressure
• Electric current during operation becomes approximately 20% lower than the normal value.
• The discharge tube of the compressor becomes abnormally hot (normally 70 to 90°C).
• The difference between high pressure and low pressure becomes almost zero.
• Electric current reaches a high level abnormally, and the value exceeds the limit of an
ammeter. In some cases, a breaker turns off.
• The compressor has a humming sound.
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CS-C9DKZW CU-2C18DKH / CS-C9DKZW CU-3C20DKH
Cooling Mode
High Pressure
Electric current during operation
Symptom