Daikin SkyAir RZR-P Series Service Manual page 46

Special Control
3.2.2 Oil Return Operation in Heating
Pc: High-pressure sensor detection value
Pe: Low-pressure sensor detection value
Tc: High-pressure equivalent saturation temperature
Te: Low-pressure equivalent saturation temperature
Ts: Suction pipe temperature detected by thermistor
[Conditions to start]
The heating oil return operation is started referring following conditions.
 Integrated amount of displaced oil
 Timer
Parts Name Symbol
RZR18/24/32P
RZQ18/24/30P
Compressor

M1C
(INV.)
Outdoor unit

M1F
fan
Four-way
20S1 Y1S
valve
Electronic
expansion EV1 Y1E
valve (Main)
Solenoid
valve (Hot SVP Y2S
gas)
Solenoid
valve
(Receiver SVG Y3S
gas
discharging)
Ending conditions
 From the preparing oil return operation to the oil return operation, and from the oil return
operation to the operation after oil return, the compressor stops for 1 minute to reduce noise
on changing of the four-way valve.
Fan
Electronic expansion valve
Function and Control
(After the power is turned ON, integrated operating-time is 2 hours and subsequently every 8
hours.)
In addition, integrated amount of displaced oil is derived from Tc, Te, and the compressor
load.
Electric Symbol
RZR36/42P
RZQ36/42P
M1C
M1F
M2F
Y1S
Y1E
Y2S

Indoor unit actuator
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Thermostat ON unit
Stopping unit
Thermostat OFF unit
Oil return preparation
Oil return operation
operation
Upper limit control 124 Hz
STEP 8 OFF
ON OFF
SH control 1400 pls
OFF ON
ON ON
130 seconds OR
SiUS281117
Post-oil-return
operation
2-step increase from
52 Hz to (Pc – Pe >
58 psi) time
STEP 8
ON
200~400 pls
ON
OFF
 6 minutes  160 seconds
OR
 Ts – Te < 9°F  Pc – Pe > 58 psi
Heating oil return operation
OFF
OFF
OFF
500 pls
500 pls
500 pls
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