Diagnosis Methods Of A Malfunction Of A Compressor - Panasonic CS-C7HKD Service Manual

15.1.1. 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.

15.1.2. 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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Cooling Mode
High Pressure Electric current during operation
Symptom