ARTH24KMTAP / AOTH24KCTA
R32 Refrigerant | Technical Manual DR_AR057EF_01 | 25 October 2021
This guide provides key specifications, piping requirements, refrigerant charging information, electrical characteristics, airflow settings, function settings, external control connections and compatible accessories for the ARTH24KMTAP / AOTH24KCTA ducted system.
Models | Specifications | Airflow | Static Pressure | Refrigerant | Electrical | Function Settings | Outdoor Controls | Accessories
1. Applicable Models
| Component | Model |
|---|---|
| Indoor unit | ARTH24KMTAP |
| Outdoor unit | AOTH24KCTA |
| System type | Ducted R32 inverter heat pump |
| Rated capacity | 7.1 kW Cooling / 8.0 kW Heating |
2. System Technical Specifications
| Specification | Value |
|---|---|
| Rated cooling capacity | 7.1 kW |
| Cooling capacity range | 3.3–8.5 kW |
| Rated heating capacity | 8.0 kW |
| Heating capacity range | 3.6–10.5 kW |
| Rated cooling input | 1.85 kW |
| Rated heating input | 1.93 kW |
| Maximum cooling input | 2.72 kW |
| Maximum heating input | 2.89 kW |
| Rated cooling current | 8.0 A |
| Rated heating current | 8.4 A |
| Maximum operating current | 20 A |
| Supply voltage | 220–240 V AC, 50 Hz |
| Permissible voltage range | 198–264 V |
| EER – Cooling | 3.84 |
| COP – Heating | 4.15 |
| Refrigerant | R32 |
Rated specifications are based on manufacturer test conditions, including a 7.5 m pipe length, zero height difference and 50 Pa standard static pressure.
3. Indoor Unit Dimensions and Airflow
Indoor unit dimensions: 240 H × 1,000 W × 700 D mm
Net weight: 32 kg
Fan type: Twin Sirocco fan
External static pressure range: 50–150 Pa
| Fan Speed | m³/h | L/s | CFM |
|---|---|---|---|
| High | 1,500 | 417 | 883 |
| Medium | 1,170 | 325 | 689 |
| Low | 1,020 | 283 | 600 |
| Quiet | 860 | 239 | 506 |
Indoor Sound Pressure
| High | Medium | Low | Quiet |
|---|---|---|---|
| 38 dB(A) | 33 dB(A) | 30 dB(A) | 27 dB(A) |
4. Static Pressure Settings – Function 26
The external static pressure is selected through the wired remote controller using Function 26.
| Setting Value | Static Pressure |
|---|---|
| 05 | 50 Pa |
| 06 | 60 Pa |
| 07 | 70 Pa |
| 08 | 80 Pa |
| 09 | 90 Pa |
| 10 | 100 Pa |
| 11 | 110 Pa |
| 12 | 120 Pa |
| 13 | 130 Pa |
| 14 | 140 Pa |
| 15 | 150 Pa |
| 31 | Standard 50 Pa – Factory Default |
| 32 | Automatic airflow adjustment |
Settings 16–30 are treated as 150 Pa. Select the setting according to the system duct resistance and the manufacturer's fan performance data.
5. Refrigerant and Piping Requirements
| Specification | AOTH24KCTA |
|---|---|
| Refrigerant | R32 |
| Factory charge | 1,800 g |
| Pre-charged pipe length | 30 m |
| Maximum pipe length | 75 m |
| Maximum height difference | 30 m |
| Liquid pipe diameter | 6.35 mm (1/4 inch) |
| Gas pipe diameter | 12.70 mm (1/2 inch) |
| Connection type | Flare |
Additional R32 Refrigerant Charge
| Pipe Length | Additional R32 | Total Charge |
|---|---|---|
| 30 m or less | 0 g | 1,800 g |
| 40 m | 200 g | 2,000 g |
| 50 m | 400 g | 2,200 g |
| 60 m | 600 g | 2,400 g |
| 70 m | 800 g | 2,600 g |
| 75 m maximum | 900 g | 2,700 g |
Formula: Additional charge (g) = (Pipe length in metres − 30) × 20, where pipe length exceeds 30 m.
6. Outdoor Unit Dimensions and Operating Range
| Specification | Value |
|---|---|
| Outdoor dimensions H × W × D | 998 × 940 × 320 mm |
| Net weight | 63 kg |
| Compressor | DC Twin Rotary |
| Cooling outdoor airflow | 3,910 m³/h |
| Heating outdoor airflow | 3,770 m³/h |
| Cooling sound pressure | 48 dB(A) |
| Heating sound pressure | 50 dB(A) |
| Cooling outdoor temperature range | -10°C to +50°C |
| Heating outdoor temperature range | -15°C to +24°C |
Outdoor Installation Clearances
Refer to the installation space diagrams on technical manual pages 50–53. Required clearances vary according to the direction and number of surrounding obstructions.
| Installation Scenario | Requirement |
|---|---|
| Rear obstruction only, top open | 100 mm minimum rear |
| Front obstruction only, top open | 500 mm minimum front |
| Rear and front obstruction, top open | 100 mm rear and 500 mm front minimum |
| Multiple outdoor units | 250 mm minimum between units; additional clearances depend on arrangement |
| Mounting above ground | 50 mm or more above floor level |
7. Electrical Characteristics
| Specification | AOTH24KCTA |
|---|---|
| Supply voltage | 220–240 V AC |
| Frequency | 50 Hz |
| Maximum operating current | 20 A |
| Starting current | 8.4 A |
| Circuit breaker – Manual specification | 25 A |
| Power cable – Manual reference | 4.0 mm² |
| Interconnecting cable – Manual reference | 1.5 mm² |
| Interconnecting cable reference length | 76 m |
8. Indoor Unit Function Settings
Function settings are accessible through the compatible wired remote controller.
| Function | Purpose |
|---|---|
| 11 | Filter sign interval |
| 26 | External static pressure |
| 30 / 31 | Indoor sensor correction – Cooling / Heating |
| 35 / 36 | Wired remote sensor correction – Cooling / Heating |
| 40 | Auto restart |
| 42 | Temperature sensor selection |
| 43 | Cold air prevention |
| 44 | Wireless controller custom code |
| 46 | External input control |
| 48 | Auxiliary temperature sensor control |
| 49 | Cooling fan energy-saving control |
| 60 | External output selection |
Function 42 – Temperature Sensor Selection
| Setting | Description |
|---|---|
| 00 | Indoor unit sensor only – Factory Default |
| 01 | Both indoor unit and wired remote sensor |
Function 48 – Auxiliary Sensor Selection
| Setting | Description |
|---|---|
| 00 | Both sensors |
| 01 | Wired remote sensor only – Factory Default |
Note: Function 48 requires Function 42 to be set to 01 and the remote controller temperature sensor to be enabled.
Function 46 – External Input Control
| Setting | Description |
|---|---|
| 00 | Operation / Stop mode 1 – Factory Default |
| 01 | Setting prohibited |
| 02 | Forced stop |
| 03 | Operation / Stop mode 2 – Remote controller disabled for stop condition |
Function 60 – External Output Selection
| Setting | Function |
|---|---|
| 00 | Operation status – Factory Default |
| 01–08 | Setting prohibited |
| 09 | Error status |
| 10 | Indoor fan operation status |
| 11 | External heater output |
Other Important Function Settings
| Function | Setting | Description |
|---|---|---|
| 40 | 00 / 01 | Auto restart enabled / disabled (00 default) |
| 43 | 00 / 01 | Cold air prevention enabled / disabled (00 default) |
| 49 | 00 / 01 / 02 | Energy-saving fan control disabled / enabled / remote controller selection (02 default) |
9. Indoor PCB External Input / Output
| Connection | Purpose |
|---|---|
| Terminals 1–2 | Operation / Stop / Forced Stop input |
| CN47 | External output – Operation, error, fan or heater status |
| CN75 | Optional external input/output PCB |
External input wiring: Twisted pair 22 AWG, maximum 150 m. Route separately from power cables.
CN47 output: High DC 12 V ± 2 V, low 0 V, maximum 50 mA, maximum cable length 25 m.
Optional UTY-XCSX PCB: Supports dry contact or applied-voltage inputs and external output contacts. Refer to manual pages 16–26 for the correct input/output combinations, wiring diagrams and rotary switch positions.
10. Group Control and Addressing
- Up to 16 indoor units can be connected in a remote controller group.
- Maximum combined remote controller cable length: 500 m.
- Non-polar 2-wire controllers use automatic indoor address setting.
- Polar 3-wire systems use manual remote controller address allocation.
- Manual addressing is limited to 15 indoor units, as specified in the manual.
- Each manually addressed indoor unit must have a unique address.
The indoor PCB SW100 DIP switches 1–4 provide remote controller address settings 00–15. Factory setting is address 00, with all four switches OFF.
Indoor PCB SW101
| Switch | Function |
|---|---|
| 1 | Drainage function: OFF enabled (factory), ON disabled |
| 2 | Setting change prohibited |
| 3 | Auxiliary heater fan delay: ON enabled, OFF disabled (factory) |
| 4 | Setting change prohibited |
11. AOTH24KCTA Outdoor PCB Controls
The AOTH24KCTA includes outdoor control functions that are configured through the outdoor PCB and optional external control connections.
Outdoor PCB External Connections
| Connector | Function |
|---|---|
| P580 | Low noise mode external input |
| PA580 | Peak cut mode external input |
| P590 | Error status external output |
| PA590 | Compressor operating status external output |
Outdoor PCB Push Buttons
| Switch | Name | Function |
|---|---|---|
| S134 | MODE | Switches between local settings and error code display |
| S133 | SELECT | Selects settings and display items |
| S132 | ENTER | Confirms selected items |
| S131 | EXIT | Returns to operation status display |
| S130 | PUMP DOWN | Pump-down operation |
Low Noise Mode
Low noise mode reduces outdoor operating noise when activated through the external control input and configured at the outdoor PCB.
- Stop the air conditioner before performing outdoor local settings.
- Press and hold MODE (S134) for at least 3 seconds.
- Confirm the POWER/MODE LED blinks 9 times, then press ENTER (S132).
- Use SELECT (S133) to locate Low Noise Mode and confirm with ENTER.
- Select the required low noise level.
- Press ENTER to confirm and EXIT to return to normal operation display.
Two low noise levels are available: Mode 1 – Low and Mode 2 – Lower. Refer to technical manual page 68 for the required LED indication pattern.
Peak Cut Mode
Peak cut mode limits current demand through a dedicated external input and outdoor PCB setting.
- Stop the air conditioner before performing settings.
- Enter local setting mode using MODE (S134) for at least 3 seconds.
- Confirm POWER/MODE blinks 9 times, then press ENTER.
- Use SELECT to locate Peak Cut Mode.
- Press ENTER and select the required peak cut level using the displayed LED indications.
- Confirm and return to normal operating display using EXIT.
Refer to technical manual page 69 for the peak cut setting and LED indication combinations.
12. Safety Devices and Protection
| Protection | Operation |
|---|---|
| Indoor PCB fuse | 250 V, 5 A |
| Indoor fan motor protection | Stops at 115 ±15°C; restarts at 70°C |
| Outdoor fan motor thermal protection | Stops at 150 ±15°C; restarts at 120 ±15°C |
| Compressor discharge temperature protection | Stops at 110°C; restart after 7 minutes |
| Compressor temperature protection | Stops at 108°C; restarts at 80°C or less |
| Outdoor temperature protection in Cooling/Dry | Stops at -20°C; restarts at -15°C |
Protection operation should be investigated before attempting to restore normal operation. Do not bypass safety devices.
13. Compatible Controllers and Accessories
Remote Controllers
| Model | Description |
|---|---|
| UTY-RNRT* | Touchscreen wired controller – Non-polar 2-wire |
| UTY-RNRYT* | Wired controller – Non-polar 2-wire |
| UTY-RVNYN | Wired controller – Polar 3-wire |
| UTY-RSRYT | Simple controller – Non-polar 2-wire |
| UTY-RHRYT | Simple controller – Non-polar 2-wire |
| UTY-RSNYN | Simple controller – Polar 3-wire |
| UTY-LBTYM | Wireless remote and IR receiver kit |
Optional Interface Accessories
| Model | Description |
|---|---|
| UTY-XSZX | Remote temperature sensor |
| UTD-LFDB | Long-life filter |
| UTY-XWZXZG | Indoor external output connect kit |
| UTY-XCSX | Indoor external input/output PCB |
| UTZ-GXDA | External input/output PCB box |
| UTY-CDPXZC / UTY-CDPXZD | Zone interface – Polar 3-wire |
| UTY-CDRXZC / UTY-CDRXZD | Zone interface – Non-polar 2-wire |
| UTY-VMSX | Modbus converter |
| UTY-VKSX | KNX converter |
| UTY-VTGX / UTY-VTGXV | Network converter |
| UTY-TERX | External switch controller |
| UTY-XWZXZ3 | Outdoor external input/output connect kit |
14. Commissioning and Service Checklist
- Confirm indoor model ARTH24KMTAP and outdoor model AOTH24KCTA.
- Confirm supply voltage, circuit protection and correct wiring.
- Verify installation clearances and outdoor airflow paths.
- Confirm pipe sizes, pipe length and height difference.
- Calculate additional R32 charge for pipe lengths above 30 m.
- Complete the required pressure testing, evacuation and leak checks.
- Confirm indoor airflow and Function 26 static pressure setting.
- Verify controller temperature sensor selection and operation.
- Check group addressing and any external control wiring.
- Verify outdoor low noise or peak cut settings if fitted.
- Confirm cooling and heating performance under the actual operating conditions.
- Record commissioning results for future technical reference.
15. Manual Reference Guide
For detailed electrical wiring diagrams, refrigerant circuits, capacity tables, service clearances and PCB LED patterns, use the relevant sections of technical manual DR_AR057EF_01.
| Technical Topic | Manual Page |
|---|---|
| Indoor specifications | 2–3 |
| Indoor dimensions and maintenance space | 4–7 |
| Indoor wiring diagram | 8 |
| Capacity tables | 9 |
| Fan performance curves | 10–13 |
| Indoor external input/output | 16–26 |
| Group control | 27–28 |
| Indoor function settings | 31–40 |
| Controller and accessory compatibility | 42–45 |
| Outdoor specifications and dimensions | 48–49 |
| Outdoor installation clearances | 50–53 |
| Refrigerant circuit and wiring diagram | 54–55 |
| Pipe length compensation | 56 |
| Additional R32 charge | 57 |
| Electrical characteristics and protections | 60–61 |
| Outdoor external input/output | 62–65 |
| Outdoor PCB local function settings | 66–69 |
This article is a technical reference summary and does not replace the manufacturer's installation manual, detailed wiring diagrams, safety procedures or applicable regulations. Confirm model-specific data before servicing.
Technical Reference – ARTH24KMTAP / AOTH24KCTA
Source: Design & Technical Manual DR_AR057EF_01 | 25 October 2021
Product specifications and design are subject to change.