Daikin VRV 5 RXYA8A7Y1B Installation And Operation Manual page 55

Main code Sub code
Master Slave 1
RYMA5+RXYA8~20A7Y1B
VRV 5 heat pump
4P739915-1 – 2023.12
Cause
High pressure switch was activated (S1PH) –
main PCB (X2A)
▪ Refrigerant overcharge
▪ Stop valve closed
Stop valve closed (liquid)
▪ Refrigerant overcharge
▪ Stop valve closed
Low pressure malfunction:
▪ Stop valve closed
▪ Refrigerant shortage
▪ Indoor unit malfunction
Electronic expansion valve malfunction
(upper heat exchanger) (Y1E) – main PCB
(X21A)
Electronic expansion valve malfunction
(inverter cooling) (Y5E) – main PCB (X23A)
Electronic expansion valve malfunction (lower
heat exchanger) (Y3E) – main PCB (X22A)
Electronic expansion valve malfunction
(receiver gas) (Y4E) – main PCB (X25A)
Electronic expansion valve malfunction
(subcool heat exchanger) (Y2E) – main PCB
(X26A)
Electronic expansion valve malfunction (liquid
injection)(Y7E)
- sub PCB (X9A)
Discharge temperature too high (R21T) –
main PCB (X33A):
▪ Stop valve closed
▪ Refrigerant shortage
Compressor casing temperature too high
(R15T) – main PCB (X33A):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Refrigerant overcharge
▪ Stop valve closed
Ambient temperature sensor malfunction
(R1T) – main PCB (X18A)
Discharge temperature sensor malfunction
(R21T): open circuit – main PCB (X33A)
Discharge temperature sensor malfunction
(R21T): short circuit - main PCB (X33A)
Compressor casing temperature sensor
malfunction (R15T): open circuit - main PCB
(X33A)
Compressor casing temperature sensor
malfunction (R15T): short circuit - main PCB
(X33A)
Suction compressor temperature sensor
(R12T) – main PCB (X35A)
Suction temperature sensor (R10T) – main
PCB (X29A)
22 Troubleshooting
Solution
Check stop valve situation or abnormalities in
(field) piping or airflow over air cooled coil.
▪ Check refrigerant amount+recharge unit.
▪ Open stop valves
Open liquid stop valve.
▪ Check refrigerant amount+recharge unit.
▪ Open stop valves.
▪ Open stop valves.
▪ Check refrigerant amount+recharge unit.
▪ Check the user interface's display or
interconnection wiring between the outdoor
unit and the indoor unit.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
▪ Open stop valves.
▪ Check refrigerant amount+recharge unit.
▪ Open stop valves.
▪ Check refrigerant amount+recharge unit.
▪ Check refrigerant amount+recharge unit.
▪ Open stop valves.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Check connection on PCB or actuator.
Installation and operation manual
SVEO SVS
(a) (b)
55