Daikin VRV R-407C PLUS Series Service Manual page 71

Outline of Control (Outdoor Unit)
Step1
Condition
(2)
Condition
Step2
(4)
Condition
(1)
Step3
Condition
(3)
Step4
[Oil return mode (common for cooling / heating)]
Outdoor unit fan and hot gas bypass solenoid valve (SVP) under oil return operation are controlled not to
actuate high pressure protection. Also outdoor fan is controlled to protect short refrigerant circulation due to
low high pressure during low ambient temperature. ( Oil returning is hard at short refrigerant circulation)
60
Outdoor unit control
Hz EV Fan
PI control when
33Hz
SHS = 15
+OFF
Pc > 2.66 MPa (63.6˚C)
PI control when
33Hz
SHS = 10
+OFF
Pc > 2.15 MPa (57.0˚C)
PI control when
33Hz
SHS = 5
+OFF
Pc > 2.05 MPa (52.7˚C)
PI control when
33Hz
SHS = 5
+OFF
HP<1.72MPa
SVP : ON
Fan : Step
HP>2.16MPa
Malfunction stop
Forced thermostat
OFF
SVP SVT SVS
Normal
OFF ON
control
Pc < 2.16 MPa (54.8 ˚C) continues for 20 sec
Normal
OFF ON
control
Pc < 1.88 MPa (49.8˚C) continues for 20 sec
Normal
OFF
ON
control
Pc < 1.72 MPa (46.4˚C) continues for 20 sec
Normal
OFF
ON
control
HP<1.49MPa
SVP : OFF
Fan : Step
HP>1.79MPa
3.09 MPa
Up to 2 times within 30 min
2.81 MPa
Indoor unit control
(Command from outdoor unit)
EV
Thermostat ON · · · 2000pls
Thermostat OFF · · · 224pls
Non-operation unit · · · 224pls
Thermostat ON · · · Normal control
Thermostat OFF · · · 224pls
Non-operation unit · · · 224pls
Thermostat ON · · · Normal control
Thermostat OFF · · · 224pls
Non-operation unit · · · 224pls
Thermostat ON · · · Normal control
Thermostat OFF · · · Normal control
Non-operation unit · · · Normal control
SVP : OFF
Fan : Step
(V0825)
Function R-407C PLUS Series
SiE 00-07
(V0824)