Daikin RYYQ8U7Y1B, Installer And User Manual

Page: 156 / 176

23 | Troubleshooting
Installer and user reference guide
156
RYYQ+RYMQ+RXYQ
VRV IV+ heat pump
4P546228-1C – 2021.11
Main code Sub code Cause Solution
Master Slave 1 Slave 2
High pressure switch was
activated (S1PH, S2PH) - A1P
(X2A , X3A) Check stop valve situation or
abnormalities in (field) piping
or airflow over air cooled coil.
▪ Refrigerant overcharge
▪ Stop valve closed
▪ Check refrigerant amount
+recharge unit.
▪ Open stop valves
Stop valve closed (liquid) Open liquid stop valve.
▪ Refrigerant overcharge
▪ Stop valve closed
▪ Check refrigerant amount
+recharge unit.
▪ Open stop valves.
Low pressure malfunction:
▪ Stop valve closed
▪ Refrigerant shortage
▪ Indoor unit malfunction
▪ Open stop valves.
▪ Check refrigerant amount
+recharge unit.
▪ Check the user interface's
display
or transmission
wiring between the outdoor
unit and the indoor unit.
Electronic expansion valve
malfunction (main) (Y1E) - A1P
(X21A) Check connection on PCB or
actuator.
Electronic expansion valve
malfunction (liquid cooling)
(Y3E) - A1P (X23A) Check connection on PCB or
actuator.
Electronic expansion valve
malfunction (subcool) (Y2E) -
A1P (X22A) Check connection on PCB or
actuator
Electronic expansion valve
malfunction (storage vessel)
(Y4E) - A1P (X25A) Check connection on PCB or
actuator
Discharge temperature too
high (R21T/R22T):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Open stop valves.
▪ Check refrigerant amount
+recharge unit.
Compressor casing
temperature too high (R8T/
R9T):
▪ Stop valve closed
▪ Refrigerant shortage
▪ Open stop valves.
▪ Check refrigerant amount
+recharge unit.
▪ Refrigerant overcharge
▪ Stop valve closed
▪ Check refrigerant amount
+recharge unit.
▪ Open stop valves.
Ambient temperature sensor
malfunction (R1T) - A1P
(X18A) Check connection on PCB or
actuator.