19 Troubleshooting
Installation and operation manual
39
RK RKXYQ8T7Y1B
VRV IV compressor unit for indoor installation
4P499900-1A – 2020.10
19.1.1
Error codes: Overview
In case of 5 HP:
Main code
Cause
Solution
▪ Heat exchanger fan malfunction.
▪ Drain pump feedback contact is open.
In the heat exchanger unit:
▪ Check connection on PCB: A1P (X15A)
▪ Check connection on terminal block (X2M)
▪ Check the fan connectors.
▪ The stop valves of the compressor unit are left closed.
▪ Refrigerant overcharge
▪ Open the stop valves on both the gas and liquid side.
▪ Recalculate the required amount of refrigerant from the
piping length and correct the refrigerant charge level by
recovering any excessive refrigerant with a refrigerant
recovery machine.
▪ The stop valves of the compressor unit are left closed.
▪ Insufficient refrigerant
▪ Open the stop valves on both the gas and liquid side.
▪ Check if the additional refrigerant charge has been
finished correctly. Recalculate the required amount of
refrigerant from the piping length and add an adequate
amount of refrigerant.
Electronic expansion valve malfunction
Heat exchanger unit: (Y1E) - A1P (X7A)
Compressor unit: (Y1E) - A1P (X22A)
Check connection on PCB or actuator.
▪ The stop valves of the compressor unit are left closed.
▪ Insufficient refrigerant
▪ Open the stop valves on both the gas and liquid side.
▪ Check if the additional refrigerant charge has been
finished correctly. Recalculate the required amount of
refrigerant from the piping length and add an adequate
amount of refrigerant.
Refrigerant overcharge
Recalculate the required amount of refrigerant from the
piping length and correct the refrigerant charge level by
recovering any excessive refrigerant with a refrigerant
recovery machine.
Ambient temperature sensor malfunction
Heat exchanger unit: (R1T) - A1P (X16A)
Check connection on PCB or actuator.
Discharge temperature sensor malfunction: open circuit /
short circuit
Compressor unit: (R2T) - A1P (X12A)
Check connection on PCB or actuator.
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 (X12A)
Compressor unit: (R5T) - A1P (X12A)
Check connection on PCB or actuator.
Coil temperature sensor malfunction
Heat exchanger unit: (R3T) - A1P (X17A)
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.
