Panasonic CS-W18MKD / CS-W24MKD / CU-W18MKD / CU-W24MKD Service Manual ▷ View online
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15. Troubleshooting
Guide
15.1 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.
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.
Normal Pressure and Outlet Air Temperature (Standard)
Gas Pressure
Mpa
(kg/cm
2
G)
Outlet air
Temperature
(°C)
Cooling Mode
0.4 ~ 0.6 (4 ~ 6)
12 ~ 16
Heating Mode 1.5 ~ 2.1 (15 ~ 21)
36 ~ 45
Condition: Indoor fan speed = High
Outdoor temperature 35°C at the cooling
mode and 7°C at the heating mode
Outdoor temperature 35°C at the cooling
mode and 7°C at the heating mode
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15.1.1 Relationship between the condition of the air conditioner and pressure and
electric current
Cooling Mode
Heating Mode
Condition of the
air conditioner
Low Pressure
High Pressure
Electric current
during operation
Low Pressure
High Pressure
Electric current
during operation
Insufficient refrigerant
(gas leakage)
Ô
Ô
Ô
Ô
Ô
Ô
Clogged capillary tube or
strainer
Ô
Ô
Ô
Ô
Ô
Ô
Short circuit in the indoor unit
Ô
Ô
Ô
Ò
Ò
Ò
Heat radiation deficiency
of the outdoor unit
Ò
Ò
Ò
Ô
Ô
Ô
Inefficient compression
Ò
Ô
Ô
Ò
Ô
Ô
• 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
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.
• 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.
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.
• 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.
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WARNING
16. Disassembly and Assembly Instructions
High Voltage is generated in the electrical parts area by the capacitor. Ensure that the capacitor has discharged sufficiently before proceeding with
repair work. Failure to heed this caution may result in electric shocks.
16.1 Indoor Electronic Controllers, Cross Flow Fan and Indoor Fan Motor
Removal Procedures
16.1.1 To remove front grille
Figure 1
16.1.2 To remove horizontal vane
Figure 2
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16.1.3 To remove power electronic controller
Figure 3
Figure
4
Figure
5
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