Heat Exchange Mode In Heating Operation Or Simultaneous Cooling / Heating Operation - Daikin VRV-WIII RWEYQ72PTJU Service Manual

SiUS30-1301
5.3 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 water heat exchanger of the condensing unit into
evaporator or condensing with load.
One condensing unit installation
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
DGR > 0
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
Two condensing units installation
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
DGR > 0
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
Four-way valve for heat
exchanger [Y7S] (For the
application of heat exchanger)
Content of the control of
electronic expansion valve [Y1E]
Function and Control
Master unit
OFF
(Condenser)
Control of heat exchange
capacity balance
DGR < 0
Master unit
ON
(Evaporator)
Control of heat exchange
capacity balance
Master unit
OFF
(Condenser)
Control of heat exchange Control of heat exchange
capacity balance capacity balance
DGR > 0 DGR < 0
Master unit
OFF
(Condenser)
Control of heat exchange
capacity balance
DGR > 0 DGR < 0
Master unit
OFF
(Condenser)
Control of heat exchange Control of heat exchange
capacity balance capacity balance
Master unit
ON
(Evaporator)
Control of heat exchange
capacity balance
DGR > 0 DGR < 0
Master unit
ON
(Evaporator)
Control of heat exchange Control of heat exchange
capacity balance capacity balance
Note 1: DGR = Target of heat exchange capacity balance
– Actual measurement of heat balance
DGR > 0: Insufficient evaporation
(Excessive condensation)
DGR < 0: Insufficient condensation
(Excessive evaporation)
2: Control of heat exchange capacity balance
Control the electronic expansion valve so that Te or Tc
will obtain the target value.
Slave unit 1
OFF
(Condenser)
Slave unit 1
ON
(Evaporator)
0 pulse
DGR < 0
Slave unit 1
ON
(Evaporator)
Slave unit 1
ON
(Evaporator)
0 pulse
Slave unit 1
ON
(Evaporator)
Normal Control
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