Oil Return Operation - Daikin RXYQ96PYDN Service Manual

Special Control
conditions of indoor units with thermostat ON, thus maximizing the equipment capacity.
psi
356
285
213
Pressure
142
71
0
[Starting conditions]
[Control]
1. Start multiple INV compressors in the system at one time.
2. Start multiple STD compressors in the system at intervals of 15 seconds.
7.3

Oil Return Operation

Used to recover refrigerant oil that flows out from the compressor to the system side by conducting the
oil-return operation. This prevents the compressor from running out of refrigerant oil.
7.3.1 Cooling Oil Return Operation
[Start conditions]
Referring to the following conditions, start cooling 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.
52
Pc
Start up STD compressors at intervals of 15 seconds.
• The system starts heating operation with thermostat ON at a high load.
• The system completes defrosting operation.
OR
• The system switches the operation mode from cooling to heating or simultaneous
cooling and heating operation.
Number of
compressors
Pe
Time
SiUS34-801A_b
INV
STD
VRVIII R-410A Heat Pump 60Hz