Daikin REYQ-AATJA, Service Manual, Page: 131 / 495

SiUS372201EA Operation Flowchart
Part 4 Functions and Control 124
Note(s)
1. Operation Flowchart
For detailed description of each function in the flow below, refer to the details on related function on
the following pages.
1. If the 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.
Stop control
(1) Stop due to error
(2) When system is in stop control
(3) Sub unit stops during master unit control
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 control
(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
(7) Heat exchanger control
Protection control
(1) High pressure protection control
(2) Low pressure protection control
(3) Discharge pipe protection control
(4) 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
(4) Outdoor unit rotation
Thermostat OFF
(2) Oil return operation (note 1)
Conditions met for defrosting
(3) Defrost operation (note1)
End of oil return operation
End of defrost operation
Conditions met for outdoor unit rotation
End of outdoor unit rotation