Heat Exchanger Control - Daikin RXYQ96PYDN Service Manual

SiUS34-801A_b
6.6

Heat Exchanger Control

In case of multi outdoor unit systems, this function is used to ensure condensing and evaporating
temperatures by changing over the air heat exchanger of the outdoor unit to the evaporator or the
condenser in response to loads while in heating operation.
[Multi outdoor unit system]
[RXYQ144PTJU]
VRVIII R-410A Heat Pump 60Hz
A1
Outdoor unit
1 2
Condenser Condenser
GR > 15 GR < -10
A2
Outdoor unit
1 2
Condenser Condenser
GR > 25 GR < -20
A3
Outdoor unit
1 2
Condenser Condenser
GR > 15 GR < -10
A4
Outdoor unit
1 2
Condenser Evaporator
Outdoor unit
Left side Right side
Condenser Condenser
GR > 25 GR < -20
Outdoor unit
GR > 25
Left side Right side
GR < -20
Evaporator Condenser
Note 1. "GR" is a numeric value representing the current balanced
condition and calculated from target condensing temperature,
target evaporating temperature, current condensing
temperature, and current evaporating temperature.
Note 2. On the system with two outdoor units, if there is no step for the
destination of transition, that step will be skipped.
B1
B2
GR > 25
GR < -20
B3
GR > 25
Outdoor unit
Left side Right side
Evaporator
GR > 15 GR < -10
Outdoor unit
Left side Right side
Evaporator Evaporator
Basic Control
Outdoor unit
1 2
– Evaporator
GR > 15 GR < -10
Outdoor unit
1 2
Evaporator Evaporator
GR > 15 GR < -10
Outdoor unit
1 2
Evaporator Evaporator
Note 1. "GR" is a numeric value
representing the current
balanced condition and
–
calculated from target
condensing temperature,
target evaporating
temperature, current
condensing temperature,
and current evaporating
temperature.
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