Heat Exchange Mode In Heating Operation Or Simultaneous Cooling / Heating Operation - Daikin VRV II REYQ8MY1B Service Manual

Basic Control
2.5 Heat Exchange Mode in Heating Operation or
Simultaneous Cooling / Heating Operation
In heating or simultaneous cooling / heating operation, a target condensing and evaporating
temperature can be secured by switching the air heat exchanger of the outdoor unit (main, sub)
into evaporator or condenser with load.
Step A1
Main heat exchanger Sub heat exchanger
Condenser
Master unit
Not used
Slave unit 1
Not used
Slave unit 2
GR > 900
Step A2
Main heat exchanger Sub heat exchanger
Not used
Master unit
Not used
Slave unit 1
Not used
Slave unit 2
GR > 250
Step A3
Main heat exchanger Sub heat exchanger
Not used
Master unit
Not used
Slave unit 1
Not used
Slave unit 2
GR > 250
Step B1
Main heat exchanger Sub heat exchanger
Evaporator
Master unit
Not used
Slave unit 1
Not used
Slave unit 2
GR > 250
Step B2
Main heat exchanger Sub heat exchanger
Evaporator
Master unit
Evaporator
Slave unit 1
Not used
Slave unit 2
GR > 250
Step B3
Main heat exchanger Sub heat exchanger
Evaporator
Master unit
Evaporator
Slave unit 1
Evaporator
Slave unit 2
68
*
• The GR is a numerical value representing the current balancing
conditions, which is computed in accordance with the target
condensing temperature, target evaporating temperature, current
Condenser
condensing temperature, and current evaporating temperature.
Condenser
• If there are no steps to receive transition when one or two outdoor
Condenser
units are installed, the steps will be skipped.
GR < –250
Condenser
Condenser
Condenser
GR < –250
Condenser
Condenser
Not used
GR < –250
Condenser
GR > –400
Not used
Not used
GR < –250
Condenser
Not used
Not used
GR < –250
Condenser
GR > 900
Not used
Not used
Step C1
Main heat exchanger Sub heat exchanger
Evaporator
Master unit
Not used
Slave unit 1
Not used
Slave unit 2
GR > 250
Step C2
Main heat exchanger Sub heat exchanger
Evaporator
Master unit
Evaporator
Slave unit 1
Not used
Slave unit 2
GR > 250
Step C3
Main heat exchanger Sub heat exchanger
Evaporator
Master unit
Evaporator
Slave unit 1
Evaporator
Slave unit 2
Si39-306
Evaporator
Not used
Not used
GR < – 250
Evaporator
Evaporator
Not used
GR < –250
Evaporator
Evaporator
Evaporator
Function