Specifications
SiUS39-602 Basic Control
Function 47
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
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Condenser Condenser
Not used
Not used
Condenser
Condenser
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Evaporator Condenser
Evaporator
Not used
Not used
Not used
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Evaporator Condenser
Evaporator
Evaporator
Not used
Not used
Step A2
Step A3
Step B1
Step B2
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Not used Condenser
Not used
Not used
Condenser
Condenser
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Not used Condenser
Not used
Not used
Condenser
Not used
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Evaporator Condenser
Not used
Not used
Not used
Not used
Step B3
GR > 900 GR < –250
GR > 250 GR < –250
GR > 250 GR < –250
GR > 250 GR < –250
GR > 250 GR < –250
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Evaporator Evaporator
Evaporator
Not used
Evaporator
Not used
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Evaporator Evaporator
Evaporator
Evaporator
Evaporator
Evaporator
Step C1
Step C2
Master unit
Slave unit 1
Slave unit 2
Main heat exchanger Sub heat exchanger
Evaporator Evaporator
Not used
Not used
Not used
Not used
Step C3
GR > 250 GR < – 250
GR > 250 GR < –250
GR > 900
GR > –400
*
• 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
condensing temperature, and current evaporating temperature.
• If there are no steps to receive transition when one or two outdoor
units are installed, the steps will be skipped.
* Not used: The meaning of "not used" is
that the refrigerant is not flowing to
heat exchanger by closing EX valves
of changing over the 4 way valves.