Daikin Aurora Series, Service Manual, Page: 55 / 333

SiUS341802E Operation Flowchart (Outdoor Unit)
Functions and Control 42
1. Operation Flowchart (Outdoor Unit)
For detailed description of each function in the flow below, refer to the details on related function on the following
pages.
Notes: 1. In the event indoor unit stops or the thermostat turns OFF while in oil return operation or defrost
operation, pump down residual operation is performed on completion of the oil return operation
or defrost operation.
2. Not performed during cooling mode.
Stop control
(1) Stop due to error
(2) When system is in stop mode
(3) Slave unit stops during master unit operation
Standby control
(1) Restart standby
(2) Crankcase heater control
Startup control
(include pressure equalization before startup)
(1) Startup control in cooling
(2) Startup control in heating
Basic control
(1) Normal Operation
(2) Compressor PI control
(3) Operation priority and rotation of
compressors
(4) Compressor step control
(5) Electronic expansion valve PI control
(6) Step control of outdoor fans
Protection control
(1) High pressure protection control
(2) Low pressure protection control
(3) Discharge pipe protection control
(4) Compressor body protection control
(5) Inverter protection control
Thermostat ON
End of
startup
control
Abnor
mality
Ther
mostat OFF
Conditions met for oil return
Special control
(1) Pump down residual operation
(note 2)
(4) Outdoor unit rotation
Thermostat OFF
(2) Oil return operation (note 1)
Conditions met for defrosting
(3) Defrost operation (note1)