Troubleshooting by Indication on the Remote Controller
Si39-504
214
Troubleshooting
3.39
“
UO
”
Outdoor Unit:
Low Pressure Drop Due to Refrigerant
Shortage or Electronic Expansion Valve Failure
Remote
Controller
Display
U0
Applicable
Models
RXYQ5MA~48MA
Method of
Malfunction
Detection
Short of gas malfunction is detected by discharge pipe temperature thermistor.
Malfunction
Decision
Conditions
Microcomputer judge and detect if the system is short of refrigerant.
Malfunction is not decided while the unit operation is continued.
Supposed
Causes
Out of gas or refrigerant system clogging (incorrect piping)
Defect of pressure sensor
Defect of outdoor unit PC board (A1P)
Defect of thermistor R2T or R4T
Troubleshooting
∗
1: Refer to “Thermistor Resistance / Temperature Characteristics” table on P299.
∗
2: Refer to “Pressure Sensor, Pressure / Voltage Characteristics” table on P301.
(V2819)
The suction
pipe temperature minus
coil temperature is 20 ˚C
or higher.
Resistance
is normal when
measured with the
suction pipe thermistor
(R2T) and coil thermistor
(R4T) disconnected
from the outdoor
unit PC
board.
∗
1
Out of gas or refrigerant
system is clogged. Requires
check of refrigerant system.
Replace the thermistor.
Replace the outdoor unit PC
board (A1P).
YES
NO
NO
Out of gas, closing of stop
valve or refrigerant system is
clogged. Requires check of
refrigerant system.
Replace main outdoor unit
PC board (A1P).
YES
YES
NO
Cooling
Low pressure
is 0.1 MPa
or less.
The
voltage
of X45A pins (2)
and (3) on main
outdoor unit PC board
(A1P) is 0.8 VDC or less.
(Low pressure
sensor output
voltage)
∗
2
NO
NO
YES
YES
Replace low pressure sensor.
Caution
Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Summary of Contents for VRV II RXYQ5MATL
Page 53: ...Specifications Si39 504 42 Specifications...
Page 115: ...Outline of Control Indoor Unit Si39 504 104 Function...
Page 161: ...Field Setting Si39 504 150 Test Operation...
Page 172: ...Si39 504 Troubleshooting by Remote Controller Troubleshooting 161...
Page 266: ...Si39 504 Piping Diagrams Appendix 255 RXYQ8MA 10MA 12MAYL E TL E 3D048033A...
Page 267: ...Piping Diagrams Si39 504 256 Appendix RXYQ14MA 16MAYL E TL E 3D048034A...
Page 271: ...Wiring Diagrams for Reference Si39 504 260 Appendix RXYQ8MA 10MA 12MAYL E 3D047088C...
Page 272: ...Si39 504 Wiring Diagrams for Reference Appendix 261 RXYQ14MA 16MAYL E 3D047089C...
Page 273: ...Wiring Diagrams for Reference Si39 504 262 Appendix 2 1 2 RXYQ MATL E RXYQ5MATL E 3D049059A...
Page 274: ...Si39 504 Wiring Diagrams for Reference Appendix 263 RXYQ8MA 10MA 12MATL E 3D049060A...
Page 275: ...Wiring Diagrams for Reference Si39 504 264 Appendix RXYQ14MA 16MATL E 3D049061A...
Page 283: ...Wiring Diagrams for Reference Si39 504 272 Appendix FXCQ40M 50M 80M 125MVE 3D039557A...
Page 285: ...Wiring Diagrams for Reference Si39 504 274 Appendix FXKQ25M 32M 40M 63MVE 3D039564B...
Page 289: ...Wiring Diagrams for Reference Si39 504 278 Appendix FXMQ40M 50M 63M 80M 100M 125MVE 3D039620B...
Page 290: ...Si39 504 Wiring Diagrams for Reference Appendix 279 FXMQ200M 250MVE 3D039621B...
Page 291: ...Wiring Diagrams for Reference Si39 504 280 Appendix FXHQ32M 63M 100MVE 3D039801D...
Page 292: ...Si39 504 Wiring Diagrams for Reference Appendix 281 FXAQ20M 25M 32MVE 40M 50M 63MVE 3D034206C...
Page 309: ...Selection of Pipe Size Joints and Header Si39 504 298 Appendix Note 1...
Page 315: ...Method of Replacing The Inverter s Power Transistors and Diode Modules Si39 504 304 Appendix...
