Daikin VRV III REYQ8PY1 Service Manual page 127

Special Control
3.3.2 Heating Oil Return Operation (including cooling / heating
simultaneous operation)
[Start conditions]
Referring to the following conditions, start heating oil return operation.
• Integral oil rise rate is reached to specified level.
OR • When cumulative compressor operating time exceeds 8 hours (2 hours when the power supply turns ON for
the first time)
Furthermore, the integral oil rise rate is calculated by Tc, Te, and compressor loads.
The higher the compressor operating step No., the cumulative refrigerant oil consumption increases.
Actuator
Compressor 1
Compressor 2
Compressor 3
Outdoor unit fan 1
Outdoor unit fan 2
Electronic expansion valve (main)
Electronic expansion valve
(subcooling)
Electronic expansion valve (refilling
refrigerant)
Four way valve (for heat changer
selection)
Four way valve (for high- and low-
pressure gas pipe selection)
Solenoid valve (main bypass)
Solenoid valve (hot gas)
Solenoid valve (liquid pipe of
refrigerant regulator)
Solenoid valve (gas discharge pipe of
refrigerant regulator)
Solenoid valve (drain pipe of
refrigerant regulator)
Solenoid valve (discharge pipe of
refrigerant regulator)
End conditions
*1: In case of multi outdoor unit system:
Master unit: It conducts the operation listed in the table above.
Slave units: Operating units conduct the operation listed in the table above.
Non-operating units conduct the operation listed in the table above after the "Oil returning" process.
(Non-operating units stop while in "Preparation" mode.)
116
Elect. symbol
Symbol
REYQ REMQ
M1C M1C
— M2C M2C
— M3C
M1F M1F
—
M2F M2F
Y1E
EVM Y1E
Y3E
Y2E
EVT Y3E
Y5E
EVJ Y4E Y2E
Y2S
20SA Y3S
Y9S
20SB Y8S Y2S
Y5S
SVE Y10S Y6S
SVP Y4S Y5S
SVL Y3S Y4S
SVG Y1S Y1S
SVO Y7S Y7S
SVT Y6S Y8S
Oil return operation
Maintain load that was applied before oil return
operation.
When current circulation rate < circulation rate required
for oil return operation, turn ON the STD compressor
every 10 seconds (up to 3 units at maximum).
When outdoor unit heat exchanger is condenser, the
fan will run under cooling fan control.
When outdoor unit heat exchanger is evaporator, the
fan will run at the fan step 7 or 8.
20SA=ON : PI control
20SA=OFF : 418pls
PI control
80pls
When outdoor unit heat exchanger is condenser, the
valve will turn OFF.
When outdoor unit heat exchanger is evaporator, the
valve will turn ON.
OFF
OFF
0pls
0pls
0pls
0pls
0pls
• Pe_min<0.22MPa
or
• After a lapse of 9 min.
Si37-701
Function