Panasonic CS-Z20XKEW Service Manual page 79

1. Measuring temperature
1) Indoor unit suction temperature, release temperature, temperature difference, → Measure by thermometer
2) 2-way valve pipe temperature in cooling mode is low temperature (benchmark：5 ~ 10°C), in heating mode
is medium temperature (benchmark：25 ~ 35°C).
3) 3-way valve pipe temperature in cooling mode is low temperature (benchmark：7 ~ 15°C) in heating mode is
high temperature (benchmark：38 ~ 50°C).
2. Measuring electric current

Measuring electric current in operation → check by clump meter (refer to table of technical characteristic
guideline)
3. Meauring pressure

Measuring gas pressure → check the pressure by manifold gauge (refer to table of technical characteristic
guideline)
4. Any sound from the expansion valve?
(when starting the operation and the outdoor unit is turned on, the expansion valve is re-set, check if there is any
edged sound or clack sound)
13.8.3 Guidance for diagnosis of refrigerant cycle
Comparison with
normal operation
Refrigerant
pressure
Operation electric
current
2-way valve
temperature
3-way valve
temperature
Suction
temperature
&
Release air
temperature
◎ Above all are based on the condition that the installation work is properly performed (no issues in indoor / outdoor
pipe connections, etc.)
High
Excess insertion of refrigerant
Heat releasing obstruction
Dirty condenser, attachment of impurity
Compressor malfunction
Excess insertion of refrigerant
Heat releasing obstruction
Dirty condenser, impurity
Excess insertion of refrigerant
Compressor malfunction
Lack of refrigerant gas • Compressor malfunction
Clogged capillary, expansion valve malfunction
Temperature difference at or less than 8°C in cooling operation • • • Causes
• Heat releasing obstruction
• Lack of refrigerant gas
• Mixture of air
• Clogged capillary
Cooling mode
Clogged capillary, expansion valve malfunction
Clogged capillary, expansion valve malfunction
• Dirty condenser
• Excess insertion of refrigerant
• Mixture of moisture
• Expansion valve malfunction
79
Low
Clog by moisture
Lack of refrigerant gas
Lack of refrigerant gas
Compressor malfunction
Mixture of air
(Insufficient evacuation)
Lack of refrigerant gas
Excess insertion of refrigerant
• Attachment of impurity
• Compressor malfunction