Heat Exchanger Control - Daikin REYQ8-48PY1B Service Manual

SiBE37-701_B
2.6

Heat Exchanger Control

While in heating or cool/heat simultaneous operation, ensure target condensing and
evaporating temperature by changing over the air heat exchange of outdoor unit to the
evaporator or the condenser in response to loads.
[Single system]
GR > 25
[Multi outdoor unit system]
Function
Outdoor unit
Left side Right side
Condenser Condenser
GR < -20
Outdoor unit
GR > 25
Left side Right side
GR < -20
Evaporator Condenser
A1
Outdoor unit
1 2 3
Condenser Condenser Condenser
GR > 15 GR < -10
A2
Outdoor unit
1 2 3
Condenser Condenser Condenser
GR > 25 GR < -20
A3
Outdoor unit
1 2 3
–
Condenser Condenser
GR > 15 GR < -10
A4
Outdoor unit
1 2 3
Condenser Evaporator Evaporator
Outdoor unit
Left side Right side
–
Evaporator
GR > 15 GR < -10
Outdoor unit
Left side Right side
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.
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
Basic Control
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.
Outdoor unit
1 2 3
– –
Evaporator
GR > 15 GR < -10
Outdoor unit
1 2 3
Evaporator Evaporator –
GR > 15 GR < -10
Outdoor unit
1 2 3
Evaporator Evaporator Evaporator
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