Panasonic Cs A18gkh Cs A24gkh Series Repair Manual

							51
14 Troubleshooting Guide
14.1. Refrigeration Cycle System
In order to diagnose malfunctions, make sure that there are no
electrical problems before inspecting the refrigeration cycle.
Such problems include insufficient insulation, problem with the
power source, malfunction of a compressor and a fan.
The normal outlet air temperature and pressure of the
refrigeration cycle depends on various conditions, the standard
values for them are shown in the table on the right. 
						

							52
14.1.1. Relationship between the condition of the air conditioner and pressure and electric
current
• Carry out the measurements of pressure, electric current, and temperature fifteen minutes after an operation is started.
14.1.2. Diagnosis methods of a malfunction of a compressor and 4-Way Valve
Cooling Mode Heating Mode
 
Low Pressure High PressureElectric current 
during operatingLow Pressure High PressureElectric current 
during operating 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
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 to 90°C).
• The difference between high pressure and low pressure becomes almost zero.
Locker 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.
Insufficient switches of the 4-way valve• 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. 
						

							53
15 Disassembly and Assembly Instructions
15.1. 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
power has been turned off. 
						

							54 
						

							55 
						

							56
15.2. Indoor Fan Motor and Cross Flow Fan Removal Procedures 
						

							57 
						

							58
16 Technical Data
16.1. Thermostat Characteristics 
						

							59
16.2. Operation Characteristics 
						

							60