Daikin REYQ96 - Page 69

Special Control SiUS39-602
58 Function
3.7.2 Stopping Operation of Slave Units During Master Unit is in Operation
With Multi-Outdoor-Unit System
In cooling operation: The system operates in Mode A or Mode B listed in the table below.
In heating operation: The system operates in Mode A or Mode B listed in the table below.
The changeover operation for mode A and B is performed for the reason that the required refrigerant amount varies
depending on the indoor unit operation capacity.
Actuator Mode-A operation Mode-B operation
Compressor OFF OFF
Outdoor unit fan STEP4 OFF
Four way valve OFF Holds
Main motorized valve (EV1) 150 pls to 300 pls 0 pls
Subcooling motorized valve (EV2) 0 pls 0 pls
Hot gas bypass valve (SVP) ON ON
Oil equalization valve (SVO) OFF OFF
Receiver gas discharging valve
(SVG)
OFF OFF
Non-operating unit liquid pipe stop
valve (SVSL)
OFF ON
Mode transition conditions To Mode B when Tc
- Tl >0.27×(Tc - Ta) +6
To Mode A when gas shortage signal
is sent from indoor unit
Ending conditions Slave units are required to operate.
Actuator Mode-A operation Mode-B operation
Compressor OFF OFF
Outdoor unit fan STEP2 STEP2
Four way valve ON ON
Main motorized valve (EV1) 0 pls 0 pls
Subcooling motorized valve (EV2) 0 pls 0 pls
Hot gas bypass valve (SVP) OFF OFF
Oil equalization valve (SVO) OFF OFF
Receiver gas discharging valve
(SVG)
OFF OFF
Non-operating unit liquid pipe stop
valve (SVSL)
OFF ON
Mode transition conditions
To Mode B when Tc
- mean temperature of
indoor unit liquid pipes>10°C
To Mode A when motorized valve of
operating outdoor unit fully opens.
Ending conditions Slave units are required to operate.
Mode A : Operating unit collects refrigerant.
Mode B : Stopping unit storage refrigerant.



Operating
unit
Stopping
unit
∗ Mode A or B operation