Troubleshooting by Indication on the Remote Controller
Si39-502A
196
Troubleshooting
3.39
“
UO
”
Outdoor Unit: Low Pressure Drop Due to Refrigerant
Shortage or Electronic Expansion Valve Failure
Remote
Controller
Display
U0
Applicable
Models
RXYQ8~30MY1K (E), YLK (E)
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 P277.
∗
2: Refer to “Pressure Sensor,” pressure / voltage characteristics table on P279.
(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 RXYQ8MY1K
Page 53: ...Specifications Si39 502A 42 Specifications...
Page 143: ...Field Setting Si39 502A 132 Test Operation...
Page 258: ...Si39 502A Wiring Diagrams for Reference Appendix 247 FXCQ40M 50M 80M 125MVE 3D039557A...
Page 260: ...Si39 502A Wiring Diagrams for Reference Appendix 249 FXKQ25M 32M 40M 63MVE 3D039564A...
Page 264: ...Si39 502A Wiring Diagrams for Reference Appendix 253 FXMQ40M 50M 63M 80M 100M 125MVE 3D039620A...
Page 265: ...Wiring Diagrams for Reference Si39 502A 254 Appendix FXMQ200M 250MVE 3D039621A...
Page 266: ...Si39 502A Wiring Diagrams for Reference Appendix 255 FXHQ32M 63M 100MVE 3D039801C...
Page 267: ...Wiring Diagrams for Reference Si39 502A 256 Appendix FXAQ20M 25M 32M 40M 50M 63MVE 3D034206A...
Page 269: ...Wiring Diagrams for Reference Si39 502A 258 Appendix FXUQ71M 100M 125MV1 3D044973...
Page 270: ...Si39 502A Wiring Diagrams for Reference Appendix 259 FXAQ20MH 25MH 32MH 40MH 50MHV1 3D046348A...
Page 271: ...Wiring Diagrams for Reference Si39 502A 260 Appendix FXLQ20MH 25MH 32MH 40MH 50MHV1 3D046787A...
Page 272: ...Si39 502A Wiring Diagrams for Reference Appendix 261 BEVQ50MVE 3D046579A Notes...
Page 273: ...Wiring Diagrams for Reference Si39 502A 262 Appendix BEVQ71M 100M 125MVE 3D044901A Notes...
Page 285: ...Piping Installation Point Si39 502A 274 Appendix...
Page 293: ...Method of Replacing The Inverter s Power Transistors and Diode Modules Si39 502A 282 Appendix...
Page 307: ...Si39 502A iv Index...
