Panasonic U-8ME1E8E Service Manual page 19

4. Output of PCB
4-3. Refrigerant control valve [RCV]
The main purpose of this valve is to adjust the flow of refrigerant (refrigerant volume) on the evaporator. When
the valve determines that there are signs of a low refrigerant volume, refrigerant is supplied from the receiver
tank to the system.
- This valve turns ON when the evaporator is refrigerant shortage.
The heat exchanger of indoor unit is evaporator in cooling operation.
The heat exchanger of outdoor unit is evaporator in heating operation.
1
- This valve turns OFF when the excessive refrigerant is in the condenser.
The heat exchanger of indoor unit is condenser in heating operation.
The heat exchanger of outdoor unit is condenser in cooling operation.
- This valve turns OFF when the outdoor unit is stopped.
- This valve might turn ON when special control is in progress.
RCV
HP
RBV
LP
RCV
HP
RBV
LP
Receiver tank holds refrigerant
ON
High pressure from RCV pushes the liquid refrigerant out of the receiver tank
Evaporator
Two-phase
flow
Refrigerant shortage in evaporator
Evaporator
Two-phase flow
Sufficient refrigerant is supplied to evaporator
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2WAY SYSTEM
Control Functions - Outdoor Unit