GENERAL AIRSTAGE Technical Reference

ARTH36KHTA / ARTH45KHTA / ARTH54KHTA / ARTH60KHTA

Service manual, diagnostics, function settings and spare parts quick reference
High static three-phase R32 inverter ducted systems with AOTH36KRTA, AOTH45KRTA, AOTH54KRTA and AOTH60KRTA outdoor units
This article is a technician quick-reference based on service manual SR_AR055EF_04 for the ARTH36KHTA, ARTH45KHTA, ARTH54KHTA and ARTH60KHTA high-static ducted range. Use the complete service manual for wiring diagrams, PCB layouts, full fault flowcharts, control logic and detailed service procedures.
Qualified service personnel only: These systems use R32 refrigerant and contain hazardous electrical voltages. Isolate the power supply before servicing and wait at least 5 minutes before touching electrical components. Refrigerant circuit work must only be performed by appropriately qualified personnel using equipment suitable for flammable refrigerants.

1. Model coverage

Indoor unitOutdoor unitSystem power supplyRefrigerant
ARTH36KHTAAOTH36KRTA380–415 V, 3N~, 50 HzR32
ARTH45KHTAAOTH45KRTA380–415 V, 3N~, 50 HzR32
ARTH54KHTAAOTH54KRTA380–415 V, 3N~, 50 HzR32
ARTH60KHTAAOTH60KRTA380–415 V, 3N~, 50 HzR32
Service manual revision: SR_AR055EF_04, dated 14 July 2023. The manual is structured into General Information, Technical Data and Parts List, Troubleshooting, Control and Functions, and Field Working.

2. Key specifications

Specification36455460
Rated cooling capacity10.0 kW12.5 kW14.0 kW15.5 kW
Rated heating capacity11.2 kW14.0 kW15.5 kW18.0 kW
High airflow695 L/s
2,500 m³/h
903 L/s
3,250 m³/h
986 L/s
3,550 m³/h
986 L/s
3,550 m³/h
Standard static pressure60 Pa
Adjustable static pressure range60–210 Pa60–260 Pa
Liquid pipeØ9.52 mm (3/8 in)
Gas pipeØ15.88 mm (5/8 in)
Factory refrigerant charge1.9 kg2.7 kg2.7 kg3.4 kg
ARTH36KHTA dimensions400 × 1,050 × 500 mm (H × W × D), net 39 kg
ARTH45 / 54 / 60KHTA dimensions425 × 1,250 × 490 mm (H × W × D), net 53 kg
AOTH36KRTA dimensions788 × 940 × 320 mm (H × W × D), net 53 kg
AOTH45 / 54KRTA dimensions998 × 940 × 320 mm (H × W × D), net 67 kg
AOTH60KRTA dimensions1,418 × 970 × 370 mm (H × W × D), net 96 kg
Factory pre-charge pipe length30 m
Maximum pipe length / height difference50 m maximum length / 30 m maximum height difference
Outdoor operating rangeCooling: -10 to 50°C   |   Heating: -15 to 24°C
R32 minimum room size: The service manual includes minimum floor-area requirements based on the total refrigerant charge and installation height. Always check the applicable installation manual and total system charge before installation or refrigerant work.

3. Error codes

When an error is detected, a connected wired remote controller displays the error code. Where an indoor indicator or IR receiver is fitted, the Operation, Timer and Economy lamps can also identify the fault by their blink pattern. The outdoor control PCB can also display faults using its LED lamps.
CodeDescription
11Serial communication error – reverse transfer (outdoor) or forward transfer (indoor)
12Wired remote controller communication error
15Automatic airflow adjustment error
18External communication error
23Combination error – check connected indoor/outdoor unit combination
26Address setting error in wired remote controller
29Connected unit number error
32Indoor unit Main PCB error
33Indoor unit motor electricity consumption detection error
39Indoor unit power supply error for fan motor
3AIndoor unit communication circuit / wired remote controller circuit error
41Room temperature sensor error
42Indoor unit heat exchanger sensor error
51Indoor unit fan motor error
53Drain pump error
5UIndoor unit error
61.5Outdoor unit missing phase wire error
62Outdoor unit Main PCB error / outdoor unit model information error
63Inverter error
64PFC circuit error
65Trip terminal L error
71Discharge thermistor error
72Compressor thermistor error
73Outdoor heat exchanger liquid-outlet or middle/outlet thermistor error
74Outdoor temperature thermistor error
77Heat sink thermistor error
84Current sensor error
86High pressure switch error or pressure sensor error
94Trip detection
95Compressor motor control error
97Outdoor unit fan motor error
994-way valve error
A1Discharge temperature error
A3Compressor temperature error
A5Low pressure error
ACHeat sink temperature error

Checking stored error memory

  1. Stop the air conditioner and disconnect the power supply.
  2. Reconnect the power supply.
  3. During the initial 3 minutes ST period, start operation and press TEST RUN on the remote controller, or press the applicable indoor/receiver MANUAL AUTO button for 10 seconds or more.
  4. The stored error is displayed during this period. The manual states the available display window is approximately 2 minutes 20 seconds after power is restored.
Erase error memory: While the stored error is displayed, press MANUAL AUTO for a manual erase where the applicable indicator unit is fitted. The memory also clears automatically after at least 2 hours of normal error-free operation, excluding Fan mode.

4. Service diagnostic reference

ComponentService check
Compressor terminalsR(U) = Red, S(V) = White, C(W) = Black. Outdoor inverter PCB outputs are P400 (U), P401 (V) and P402 (W).
AOTH36KRTA compressor winding2.164 Ω ±7% at 25°C. A reading of 0 Ω or infinity indicates a defective compressor.
AOTH45 / 54KRTA compressor winding1.546 Ω ±8% at 20°C.
AOTH60KRTA compressor winding1.160 Ω ±8% at 20°C.
Outdoor EEV coilMeasure from Red common to Blue, Orange, Yellow and White: 46 Ω ±3 Ω at 20°C. The service procedure also specifies a 12 V DC PCB drive check.
Indoor / outdoor DC fan motorWith the motor disconnected, check between Vm and GND. If the resistance is below 300 kΩ, the manual directs replacement of the fan motor and associated controller PCB.
Pressure switch – P770Contact changes Short → Open at approximately 4.2 to 4.05 MPa and Open → Short at 3.2 ±0.15 MPa.
Pressure sensor – P20Measure between P20 terminals 2–3 with the connector fitted. Reference outputs: 0 MPa = 0.50 V, 1 MPa = 1.30 V, 2 MPa = 2.10 V, 3 MPa = 2.90 V, 4 MPa = 3.70 V, 5 MPa = 4.50 V.

Thermistor quick checks

Sensor0°C20°C30°C
Indoor room thermistor33.62 kΩ12.54 kΩ8.04 kΩ
Indoor heat exchanger / pipe thermistor176.03 kΩ62.91 kΩ39.57 kΩ
Diagnosis: Use the error-specific flowchart in the full service manual before condemning a PCB, compressor or motor. The flowcharts include connector checks, supply-voltage checks, serial-signal measurements and component-specific tests.

5. Common function settings

Indoor function settings can be changed using the applicable wired remote controller. After completing a function-setting change, turn the power off, wait at least 30 seconds, then turn the power back on. The setting does not become active until the system is power-cycled.
FunctionPurposeUseful settings
11Filter sign interval00 = 2,500 h; 01 = 4,400 h; 02 = 1,250 h; 03 = No indication (factory)
26Static pressure06 = 60 Pa through 26 = 260 Pa; 31 = Standard 60 Pa (factory); 32 = Automatic airflow adjustment. ARTH36 is limited to 210 Pa; ARTH45/54/60 to 260 Pa.
30 / 31Room temperature correction – indoor sensorCooling / heating correction from -4.0°C to +4.0°C. 00 = Standard (factory). Refer to the manual table for the required setting value.
35 / 36Room temperature correction – wired controller sensorCooling / heating correction from -4.0°C to +4.0°C. Function 42 must be set appropriately when using the wired-controller sensor.
40Auto restart00 = Enable (factory); 01 = Disable
42Room temperature sensor switching00 = Indoor unit (factory); 01 = Both indoor unit and wired-controller sensors
43Cold air prevention00 = Enable (factory); 01 = Disable
46External input control00 = Operation/Stop mode 1, remote controller enabled (factory); 01 = prohibited; 02 = Forced stop; 03 = Operation/Stop mode 2, remote controller disabled
48Room temperature sensor switching (Aux.)00 = Both; 01 = Wired remote controller (factory). Function 42 must be 01 for this function to operate.
49Indoor fan energy saving in cooling00 = Disable; 01 = Enable; 02 = Remote controller (factory)
60External output terminal function00 = Operation status (factory); 01–08 = prohibited; 09 = Error status; 10 = Indoor unit fan operation status; 11 = External heater output
68Auto mode type00 = Single setpoint auto mode (factory); 01 = Dual setpoint auto mode
69Deadband value00 = 0°C (factory); 01 = 0.5°C through 09 = 4.5°C

Indoor PCB settings

SW100Remote controller address setting for 3-wire control. Addresses 00–15 are set using DIP switches 1–4. Factory setting is address 00 with all switches OFF.
SW101 switch 3Fan delay. ON = enabled; OFF = disabled (factory). When enabled, the indoor fan continues for 1 minute after the indoor unit stops while operating in conjunction with an auxiliary heater.

Outdoor local settings

Outdoor unit functions are set from the outdoor control PCB. The service manual identifies the following switch buttons:

SwitchFunction
S134 – MODESwitches between local setting and error-code display.
S133 – SELECTMoves through the available local settings / display selections.
S132 – ENTERConfirms the selected local setting / display selection.
S131 – EXITReturns to the normal operation-status display.
S130 – PUMP DOWNStarts the pump-down operation.

The local setting procedure includes Low Noise mode and Peak Cut mode. Peak Cut selections are 0%, 50%, 75% or 100% of rated input ratio. Refer to the full manual for the required LED patterns and setting sequence.

6. Common service parts

Part numbers below are taken from the supplied service manual. Parts information can change; always confirm the latest supersession and availability before ordering.

Indoor unit parts

PartPart No.Applies to
Main PCB9712270022ARTH36KHTA
Main PCB9712270039ARTH45KHTA
Main PCB9712270046ARTH54KHTA
Main PCB9712270053ARTH60KHTA
Power supply PCB9712275003ARTH36KHTA
Power supply PCB9712213005ARTH45KHTA / ARTH54KHTA / ARTH60KHTA
Communication PCB9710019005All indoor models
DC fan motor9604104008ARTH36KHTA
DC fan motor9604111006ARTH45KHTA / ARTH54KHTA / ARTH60KHTA
Evaporator assembly9372584347ARTH36KHTA
Evaporator total assembly9380206156ARTH45KHTA / ARTH54KHTA / ARTH60KHTA
Room thermistor9900826062ARTH36KHTA
Room thermistor9703299254ARTH45KHTA / ARTH54KHTA / ARTH60KHTA
Pipe thermistor9901075049ARTH36KHTA
Pipe thermistor9901075056ARTH45KHTA / ARTH54KHTA / ARTH60KHTA
Wired remote controller9383418181All indoor models

Outdoor unit parts

PartPart No.Applies to
Main PCB9711432452AOTH36KRTA
Main PCB9711432469AOTH45KRTA
Main PCB9711432476AOTH54KRTA
Main PCB9711432483AOTH60KRTA
Inverter PCB9709688328AOTH36KRTA
Inverter PCB9709688335AOTH45KRTA / AOTH54KRTA
Inverter PCB9709688342AOTH60KRTA
Compressor9383821011AOTH36KRTA – compressor assembly
Compressor9810626004AOTH45KRTA / AOTH54KRTA
Compressor9810628008AOTH60KRTA
DC fan motor9603732011AOTH36KRTA / AOTH60KRTA; AOTH60 uses two motors
DC fan motor9603733018AOTH45KRTA / AOTH54KRTA
Propeller fan9383336003All outdoor models; AOTH60 uses two fans
Pressure switch9900186029All outdoor models
Expansion valve coil9970209000All outdoor models
Expansion valve assembly9370947373AOTH36KRTA
Expansion valve assembly9370947311AOTH45KRTA / AOTH54KRTA
Expansion valve assembly9370947342AOTH60KRTA
Compressor thermistor9900985035AOTH36KRTA
Compressor thermistor9900985028AOTH45KRTA / AOTH54KRTA / AOTH60KRTA
Condenser assembly9374420612AOTH36KRTA
Condenser assembly9374420605AOTH45KRTA / AOTH54KRTA
Heat exchanger unit9383860188AOTH60KRTA

7. Compatible controllers and optional parts

AccessoryModelConnection / purpose
Wired Remote Controller – Touch Panel / zone capableUTY-RNRTNon-polar 2-wire
Wired Remote Controller – Touch PanelUTY-RNRYTNon-polar 2-wire
Wired Remote ControllerUTY-RVNYNPolar 3-wire
Simple Remote ControllerUTY-RSRYT / UTY-RHRYTNon-polar 2-wire
Simple Remote ControllerUTY-RSNYNPolar 3-wire
IR Receiver Kit with wireless controllerUTY-LBTYMConnects to CN48 on indoor Main PCB
Remote Sensor UnitUTY-XSZXTRoom temperature sensor; connects to CN8
Long-life FilterUTD-LF60KAFor ARTH36KHTA
External Connect KitUTY-XWZXZGControl output; connects to CN47
External Input / Output PCBUTY-XCSXConnects to CN65 or CN75; External Connect Kit required
External Input / Output PCB BoxUTZ-GXEAMounting box for the external input/output PCB
Zone Control Interface – 3-wireUTY-CDPXZC / UTY-CDPXZDPolar 3-wire zone control interface
Zone Control Interface – 2-wireUTY-CDRXZC / UTY-CDRXZDNon-polar 2-wire zone control interface
Modbus ConverterUTY-VMSXUART connection via CN65 or CN75
KNX ConverterUTY-VKSXUART connection via CN65 or CN75
Network ConverterUTY-VTGXConnects the single-split system to a VRF network via Y1/Y2
Network Converter – AC power supplyUTY-VTGXVConnects the single-split system to a VRF network via Y1/Y2
External Switch ControllerUTY-TERXExternal sensor/switch control via Y1/Y2
Outdoor External Connect KitUTY-XWZXZ3Outdoor external input/output functions

8. What is covered in the full service manual

General InformationSpecifications, dimensions, installation clearances, maintenance access and R32 minimum room-size requirements.
Technical Data & PartsExploded parts, accessories, optional parts, refrigerant circuit diagrams, wiring diagrams and PCB diagrams.
TroubleshootingError memory, error codes, fault-by-fault flowcharts, troubleshooting without error codes, compressor/EEV/fan checks, pressure checks and thermistor resistance tables.
Control & FunctionsCompressor rotation control, auto changeover, indoor/outdoor fan control, timers, defrost, auto restart, economy, fresh-air control, EEV control, drain-pump control, demand response, peak cut, low-noise operation and protective controls.
Field WorkingIndoor and outdoor function settings plus indoor/outdoor external input and output configuration.
Freshdesk attachment: Attach the complete ARTH36–60KHTA / AOTH36–60KRTA service manual to this solution so technicians can open the original wiring diagrams, PCB diagrams and detailed troubleshooting procedures when required.
Technical note: This article is a quick-reference summary. Always verify the model, serial number, current service documentation and latest spare-part supersession before diagnosis, repair or ordering. Testing values are reference values from the supplied service manual; measurement conditions and tolerances must be followed as specified in the manual.