62
15.1.1 Relationship Between the Condition of the Air Conditioner and Pressure and
Electric Current
Condition of the
air conditioner
Cooling Mode
Low Pressure
High Pressure
Electric current during operation
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 measurement 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
Symptom
Insufficient compressing of a compressor
• Electric current during operation becomes approximately 20% lower than the normal value.
• The discharge tube of the compressor becomes abnormally hot (normally 70°C to 90°C).
• The different between high pressure and low pressure becomes almost zero.
Locked compressor
• 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.
