Daikin REYQ72 Serveice Manual page 62

SiUS39-602
3.2.2 Oil Return Operation in Heating Operation
[Starting conditions]
Start oil return operation in heating operation referring to the following conditions.
Cumulative compressor operating time after power supply turns on exceeds 2 hours and the
time after the completion of previous oil return operation exceeds 8 hours. And cumulative oil
return is calculated based on Tc, Te compressor load.
Actuator
Compressor
Outdoor unit fan
Four way valve 1
Four way valve 2
Main motorized valve (EV1)
Sub motorized valve (EV2)
Sub-cooling motorized valve (EV3)
Hot gas bypass (SVP)
Oil equalization valve (SVO)
Receiver gas charging valve (SVL)
Receiver gas discharge valve (SVG) OFF
Discharge gas stop valve (SVR)
Non-operating unit liquid pipe stop
valve (SVSL)
High pressure gas pipe pressure
reduction valve (SVC)
Ending conditions
Fan
Electronic expansion valve
<In condition of oil return operation>
Compressor cumulative operation time > 8 hours
(However, 2 hours after turning power on first time.)
Function
Oil return preparation
operation
Upper limit control
STEP7
or
STEP8
Depend on previous heat
exchange mode
Depend on previous heat
exchange mode
Four way valve 1
OFF:1400 pls
ON:SH control
Four way valve 2
OFF:1400 pls
ON:SH control
0 pls
OFF
ON
OFF
ON
ON
OFF
2 min.
Indoor unit actuator
Cooling Thermostat ON unit
Heating Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Oil return operation
124 Hz + ON
OFF
OFF
OFF
1400 pls
1400 pls
0 pls
ON
ON
OFF
OFF
OFF
OFF
ON
• 6 min.
or
• Ts - Te<9
Heating oil return operation
Set Fan Speed
Special Control
Post-oil-return operation
1-step increase from
(74Hz + OFF) to
(Pc - Pe > 0.4 MPa) time.
STEP8
ON
OFF
180 pls
1400 pls
0 pls
ON
ON
OFF
OFF
OFF
OFF
ON
• 160 sec.
or
• Pc - Pe>58 psi
OFF
OFF
OFF
512 pls
512 pls
512 pls
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