Reference> Analysis Method For No Error Code, No Cooling / No Warming - Panasonic CU-Z20VKE Series Installation Instruction

13.8 <Reference> Analysis method for no error code, no cooling / no
warming
13.8.1 Preparation for appropriate diagnosis
In order to obtain appropriate operation characteristics, minimum 15 minutes or more operation time [testing
operation (rated operation)] is required.
1. Method of rated operation (rated operation)
For the models which have two buttons of "emergency operation and forced cooling operation", press forced
cooling button once. For the models which have only emergency operation button, press the button once for
5 seconds and when hear "beep" sound, release the button. Then, cooling operation starts.
2. Checking the mal-functions of indoor / outdoor units
1) Any obstacles against heat release and air suction? (short circuit)
(Forget to remove the outdoor unit cover or fallen leaves blocking the outdoor unit)
2) Are the indoor unit air filters clean? (obstructing heat suction)
3) Is the setting temperature on the remote controller correct? (is the setting temperature set at lower/higher
than the room temperature?)
13.8.2 Understanding and verification of refrigerant cycle
「Indoor 」
Low
temp/
Pressure
Mid temp /
liquid
high pressure
liquid
Suction temp
Heat exchanger
temp
Evaporator
（EVA）
Fan
High temp / high
pressure
Air
Low temp
Low pressure
Air
Indoor unit Temp difference
Suction temp ＜Cooling＞ ８ or more
Release temp ＜Heating＞ or more
１４
＊Measured after 15 mins with strong
fan operation
Low temp /
Liquid side
Low pressure
liquid
2-way
valve
Mid temp /
High temp
liquid
(Cooling Heating
High temp /
(Heating)
High pressure
Gas pressure 2.2～ 3.0MPa
Air
Gas side
3-way
Low temp /
valve
Low pressure
Air
(Cooling)
Gas pressure 0.9～1.2MPa
76
Outdoor」
「
Expansion
valve
Low temp /
Low pressure
Liquid
Capillary tube
)
Condenser
（COND）
4-way
valve
Low temp /
Low pressure
Air
Release temp
Compressor
（COMP）
Mid temp /
High pressure
Liquid
Outdoor temp
Fan
FM
Heat exchanger
temp
High temp
High pressure
Air