Oil Return Operation - Daikin RXYQ-TA Series Service Manual

SiUS341615E
7.3

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
Ts1: Suction pipe temperature detected by thermistor R3T
7.3.1 Oil Return Operation in Cooling
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
Inverter compressor 1
Inverter compressor 2
Inverter fan 1
Inverter fan 2
Electronic expansion valve (Main)
Electronic expansion valve
(Injection)
Four way valve
Solenoid valve (Accumulator oil
return)
Solenoid valve (Oil return 1)
Solenoid valve (Oil return 2)
Ending conditions
: equipped
–: not equipped
∗1: RXYQ96/120TA only
Fan
Electronic expansion valve
Functions and Control
Electric Symbol RXYQ72-120TA RXYQ144/168TA Function of Functional Part
M1C
M2C
M1F
M2F
Y1E
Y2E
Y1S
Y2S
Y3S
Y4S
Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
—
∗1
( )
—
Cooling oil return operation
Remote controller setting
OFF
Remote controller setting
Normal control
224 pulses
Normal control with forced thermostat
ON
Special Control
Capacity step PI control
TC control
3,000 pulses
0 pulse
ON
ON
ON
· A lapse of 3 minutes.
&
· Ts1–Te < 3˚C (5.4˚F)
OR
· A lapse of 6
minutes while
the frequency is
more than that
of oil return
operation.
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