8 Troubleshooting
Installation and operation manual
23
RKXYQ5T7Y1B
VRV IV compressor unit for indoor installation
4P408443-1 – 2015.07
Main code
Cause
Solution
Heat exchanger gas sensor malfunction
Heat exchanger unit: (R2T) - A1P (X17A)
Check connection on PCB or actuator.
Suction temperature sensor malfunction
Compressor unit: (R3T) - A1P (X12A)
Compressor unit: (R5T) - A1P (X12A)
Check connection on PCB or actuator.
Coil temperature sensor malfunction
Heat exchanger unit: (R3T) - A1P (X18A)
Check connection on PCB or actuator.
Liquid temperature sensor (after subcool HE) malfunction
Compressor unit: (R7T) - A1P (X13A)
Check connection on PCB or actuator.
Gas temperature sensor (after subcool HE) malfunction
Compressor unit: (R4T) - A1P (X12A)
Check connection on PCB or actuator.
High pressure sensor malfunction: open circuit / short circuit
Compressor unit: (BIPH) - A1P (X17A)
Check connection on PCB or actuator.
Low pressure sensor malfunction: open circuit / short circuit
Compressor unit: (BIPL) - A1P (X18A)
Check connection on PCB or actuator.
Transmission compressor unit - inverter: INV1 transmission
trouble
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.
Insufficient supply voltage
Check if the supply voltage is supplied properly.
Malfunction code: System test run not yet executed (system
operation not possible)
Execute system test run.
▪ No power is supplied to the compressor unit.
▪ Transmission wiring malfunction
▪ Check if all units are powered on.
▪ Check the transmission wiring.
▪ 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.
▪ Improper type of indoor units are connected.
▪ Mismatch of compressor unit and heat exchanger unit.
▪ Check the type of indoor units that are currently
connected. If they are not proper, replace them with
proper ones.
▪ Check if the compressor unit and heat exchanger unit are
compatible.
▪ The stop valves of the compressor unit are left closed.
▪ The piping and wiring of the specified indoor unit or heat
exchanger unit are not connected correctly to the
compressor unit.
▪ Open the stop valves on both the gas and liquid side.
▪ Confirm that the piping and wiring of the specified indoor
unit or heat exchanger unit are connected correctly to the
compressor unit.
