Panasonic CS-C7HKD / CS-C9HKD / CS-C12HKD / CU-C7HKD / CU-C9HKD / CU-C12HKD Service Manual ▷ View online
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15.1.1.
Relationship between the condition of the air conditioner and pressure and electric
current
current
• 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
Cooling Mode
Condition of the air
conditioner
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
Nature of fault
Symptom
• Electric current during operation becomes approximately 20% lower than the normal value.
Insufficient compressing of a compressor
• 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.
Locked compressor
• The compressor has a humming sound.
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16 Disassembly and Assembly Instructions
16.1. Indoor Electronic Controllers and Control Board Removal Procedures
WARNING
• Cautions! When handling electronic controller, be careful of electrostatic discharge.
• Be sure to return the wiring to its original position.
• There are many high voltage components within the heat sink cover so never touch the interior during operation. Wait at least two minutes after
• Be sure to return the wiring to its original position.
• There are many high voltage components within the heat sink cover so never touch the interior during operation. Wait at least two minutes after
power has been turned off.
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16.2. Indoor Fan Motor and Cross Flow Fan Removal Procedures
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