Daikin RTSQ20PY1 Service Manual page 120

Special Control
8.2.2 Heating Oil Return Operation
[Start conditions]
Referring to the following conditions, start heating oil return operation.
• Integral oil rise rate (*1) 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)
*1 The integral oil rise rate:
The higher the compressor operating step No., the cumulative refrigerant oil consumption increases.
<Outdoor unit>
Elect.
Actuator
Symbol
Compressor 1 M1C
Compressor 2 M2C
Compressor 3 M3C
Outdoor unit fan 1 M1F
Outdoor unit fan 2 M2F
Electronic
expansion valve Y1E
(main)
Electronic
expansion valve Y3E
(subcooling)
Electronic
expansion valve Y2E
(refrigerant charge)
Solenoid valve
(gas purging pipe of
Y1S
refrigerant
regulator)
Four way valve
(for heat changer Y3S
selection)
Solenoid valve
(liquid pipe of
Y4S
refrigerant
regulator)
Solenoid valve
Y5S
(hot gas)
Solenoid valve
Y6S
(main bypass)
Solenoid valve
(discharge pipe of
Y7S
refrigerant
regulator)
Solenoid valve
(discharge pipe of
Y8S
refrigerant
regulator)
Four way valve
(for high- and low-
Y2S
pressure gas pipe
selection)
Ending 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.)
109
In preparation
Step 1 Step 2
52 Hz
OFF
Maintaining
the current
step
Same step as
that in normal Fan Control
heating
Same step as
that in normal OFF
heating
Same step as
that in normal 480 pls
heating
Same step as
that in normal 0 pls
heating
80 pls 80 pls
Same step as Same step as
that in normal that in normal
heating heating
ON OFF
Same step as Same step as
that in normal that in normal
heating heating
Same step as
that in normal ON
heating
OFF ON
Same step as Same step as
that in normal that in normal
heating heating
Same step as Same step as
that in normal that in normal
heating heating
OFF ON
• After
a lapse
170 sec.
or
of 1 min.
• Pc-Pe
<0.5MPa
After oil return operation
In oil return
operation
Step 1
RTSQ10,
12P: 232Hz
RTSQ14,
16P: 210Hz
OFF
ON
ON
Fan Control
Fan: Step 8
OFF
480 pls 480 pls
0 pls 0 pls
80 pls 80 pls
Same step as Same step as
that in normal that in normal
heating heating
OFF OFF
Same step as Same step as
that in normal that in normal
heating heating
OFF ON
ON ON
Same step as Same step as
that in normal that in normal
heating heating
Same step as Same step as
that in normal that in normal
heating heating
ON ON
• After • After
a lapse a lapse
or or
of 4 min. of 1 min.
• TsA-Te • Pc-Pe
<5°C <0.5MPa
SiBE31-801_C
Step 2
Increase the
operating
124 Hz
frequency in
increments of
2 steps per
OFF
20 sec. until
OFF
"Pc-Pe>4MPa.
Fan: Step 8
55 pls
0 pls
80 pls
Same step as that in normal
heating
ON
Same step as that in normal
heating
OFF
OFF
Same step as that in normal
heating
Same step as that in normal
heating
OFF
• After a lapse of
160sec.
or
• Pc-Pe>0.4MPa
Function