Daikin RXQ12AHR, Service Manual

Page: 97 / 321

SiAF341904E Special Control
Part 4 Functions and Control 91
7.2 Oil Return Operation
In order to prevent the compressor from running out of oil, the oil return operation is conducted
to recover oil that has flowed out from the compressor to the system side.
Tc : High pressure equivalent saturation temperature
Te : Low pressure equivalent saturation temperature
Ts: Suction pipe temperature detected by thermistor R3T
Starting conditions
Referring to the set conditions for the following items, start the oil return operation in cooling.

Cumulative oil feed rate
 Timer setting (Make this setting so as to start the oil return operation when the initial
cumulative operating time reaches 2 hours after power supply is turned ON and then every 8
hours.)
Furthermore, the cumulative oil feed rate is computed from Tc, Te, and compressor loads.
Part Name
Electric
Symbol
RXQ6-12A RXQ14A RXQ16-20A Function of Functional Part
Inverter compressor 1 M1C
  
Capacity step PI control
Inverter compressor 2 M2C — —

Inverter fan 1 M1F
  
TC control
Inverter fan 2 M2F —
 
Electronic expansion valve
(Injection)
Y2E
  
0 pulse
Electronic expansion valve
(Refrigerant auto charge)
Y4E
  
480 pulse
Solenoid valve (Oil return 1) Y3S
  
ON
Solenoid valve (Oil return 2) Y4S — —

Ending conditions
&
OR
· A lapse of 3 minutes.
· Ts1–Te < 3°C
· A lapse of 6 minutes
while the frequency
is more than that of
oil return operation.
Indoor unit actuator Cooling oil return operation
Fan Thermostat ON unit Remote controller setting
Non-operating unit OFF
Thermostat OFF unit Remote controller setting
Electronic expansion valve Thermostat ON unit Normal control
Non-operating unit 224 pulse
Thermostat OFF unit Normal control with forced thermostat
ON