Daikin VRV III REYQ8PY1, Service Manual

Page: 127 / 452

Special Control Si37-701
116 Function
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.
• 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.
*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.)
Actuator Symbol
Elect. symbol
Oil return operation
REYQ REMQ
Compressor 1
—
M1C M1C
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).
Compressor 2 M2C M2C
Compressor 3 — M3C
Outdoor unit fan 1
—
M1F M1F
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.
Outdoor unit fan 2 M2F M2F
Electronic expansion valve (main) EVM
Y1E
Y3E
Y1E
20SA=ON : PI control
20SA=OFF : 418pls
Electronic expansion valve
(subcooling)
EVT
Y2E
Y5E
Y3E PI control
Electronic expansion valve (refilling
refrigerant)
EVJ Y4E Y2E 80pls
Four way valve (for heat changer
selection)
20SA
Y2S
Y9S
Y3S
When outdoor unit heat exchanger is condenser, the
valve will turn OFF.
When outdoor unit heat exchanger is evaporator, the
valve will turn ON.
Four way valve (for high- and low-
pressure gas pipe selection)
20SB Y8S Y2S OFF
Solenoid valve (main bypass) SVE
Y5S
Y10S
Y6S OFF
Solenoid valve (hot gas) SVP Y4S Y5S 0pls
Solenoid valve (liquid pipe of
refrigerant regulator)
SVL Y3S Y4S 0pls
Solenoid valve (gas discharge pipe of
refrigerant regulator)
SVG Y1S Y1S 0pls
Solenoid valve (drain pipe of
refrigerant regulator)
SVO Y7S Y7S 0pls
Solenoid valve (discharge pipe of
refrigerant regulator)
SVT Y6S Y8S 0pls
End conditions
•
Pe_min<0.22MPa
•
After a lapse of 9 min.
OR
or