19 Troubleshooting
Installation and operation manual
41
RK RKXYQ8T7Y1B
VRV IV compressor unit for indoor installation
4P499900-1A – 2020.10
Main code
Sub code
Cause
Solution
Heat exchanger gas sensor malfunction
Heat exchanger unit: (R2T) - A1P (X18A)
Check connection on PCB or actuator.
Suction temperature sensor malfunction
Compressor unit: (R3T) - A1P (X30A)
Check connection on PCB or actuator.
Suction temperature sensor malfunction
Compressor unit: (R7T) - A1P (X30A)
Check connection on PCB or actuator.
De-icing temperature sensor malfunction
Heat exchanger unit: (R3T) - A1P (X17A)
Check connection on PCB or actuator
Liquid temperature sensor (after subcool HE)
malfunction
Compressor unit: (R5T) - A1P (X30A)
Check connection on PCB or actuator.
Gas temperature sensor (after subcool HE)
malfunction
Compressor unit: (R6T) - A1P (X30A)
Check connection on PCB or actuator.
High pressure sensor malfunction
Compressor unit: (S1NPH): open circuit - A1P
(X32A)
Check connection on PCB or actuator.
High pressure sensor malfunction
Compressor unit: (S1NPH): short circuit - A1P
(X32A)
Check connection on PCB or actuator.
Low pressure sensor malfunction
Compressor unit: (S1NPL): open circuit - A1P
(X31A)
Check connection on PCB or actuator.
Low pressure sensor malfunction
Compressor unit: (S1NPL): short circuit - A1P
(X31A)
Check connection on PCB or actuator.
Transmission outdoor unit - inverter: INV1
transmission trouble
Compressor unit: A1P (X20A, X28A, X42A)
Check connection.
INV1 unbalanced power supply voltage
Check if power supply is within range.
Heat exchanger unit capacity setting malfunction.
Check the type of heat exchanger unit. If
necessary, replace the heat exchanger unit.
Reversed power supply phase malfunction
Correct phase order.
Reversed power supply phase malfunction
Correct phase order.
INV1 voltage power shortage
Check if power supply is within range.
INV1 power phase loss
Check if power supply is within range.
Malfunction code: System test run not yet
executed (system operation not possible)
Execute system test run.
Faulty wiring to Q1/Q2 or indoor - outdoor
Check (Q1/Q2) wiring. Do NOT use Q1/Q2.
Faulty wiring to Q1/Q2 or indoor - outdoor
Check (Q1/Q2) wiring. Do NOT use Q1/Q2.
System test run abnormal ending
Execute test run again.
Warning: faulty wiring to Q1/Q2
Check Q1/Q2 wiring. Do NOT use Q1/Q2.
Malfunction code: faulty wiring to Q1/Q2
Check Q1/Q2 wiring. Do NOT use Q1/Q2.
▪ Too many indoor units are connected to F1/F2
line
▪ Bad wiring between outdoor and indoor units
Check indoor unit amount and total capacity
connected.
▪ System mismatch. Wrong type of indoor units
combined (R410A, R407C, RA, etc). Indoor unit
malfunction
▪ Heat exchanger unit malfunction
▪ Check if other indoor units have malfunction and
confirm indoor unit mix is allowed.
▪ Check the transmission wiring to the heat
exchanger unit.