Panasonic CS-A9KKD Service Manual page 90

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 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 and 4-way Valve
Nature of fault
Insufficient compressing of a compressor
Locked compressor
Insufficient switches of the 4-way valve
Cooling Mode
Low Pressure High Pressure
• 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.
• 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.
• Electric current during operation becomes approximately 80% lower than the normal value.
• The temperature different between from the discharge tube to the 4-way valve and from
suction tube to the 4-way valve becomes almost zero.
Electric current
Low Pressure
during operation
Symptom
90
Heating Mode
Electric current
High Pressure
during operation