Daikin VRV III REYQ8PY1 Service Manual page 104

Si37-701
2. When switching operation from heating to cooling
In heating
operation
In equalization
To cooling
operation
Refrigerant Circuit
First, the electric expansion valve and the solenoid valve for EVHS, EVH, EVL and EVLS of
the indoor unit will be closed.
Next, open the EVLS, and it makes to balance the system pressure.
Finally, EVL and EVLS are opened and the electric expansion valve of the indoor unit is
opened to start the operation as a cooling circuit.
Indoor Unit
Heating
Unit
Indoor Unit
(Close)
In
equalization
Indoor Unit
Cooling
Unit
Refrigerant Flow for Each Operation Mode
BS Unit
Liquid
Pipe
EVSC
EVHS
Dual
Pressure
Gas Pipe
EVH
EVL
Suction
Pipe
EVLS
BS Unit
Liquid
Pipe
EVSC
EVHS (Close)
Dual
Pressure
Gas Pipe
EVH (Close)
EVL (Close)
Suction
Pipe
EVLS (Open)
BS Unit
Liquid
Pipe
EVSC
EVHS
Dual
Pressure
Gas Pipe
EVH
EVL
Suction
Pipe
EVLS
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