General Assist Technical Reference
Wall-Mounted Split Installation Guide
ASTG18KMCA / ASTG22KMCA / ASTG24KMCA
For AOTG18KMCA / AOTG22KMCA / AOTG24KMCA R32 outdoor units
R32 flammable refrigerant: Installation and refrigerant work must be completed by appropriately qualified personnel using R32/R410A-rated tools. Remove ignition sources, maintain ventilation and use a suitable R32 leak detector.
Important - flareless indoor joint: The indoor unit does not use a conventional flare connection. It uses a factory-fitted flareless joint nut assembly. Follow the insertion-mark and tightening procedure in this guide. If the assembly is loosened after being fully tightened, it must be replaced with a new flareless joint nut assembly.
Minimum room area: Install, operate and store the indoor unit in a room with a floor area greater than 2.06 m². Mechanical connections must remain accessible for maintenance.
1. Quick specifications
| Item | Requirement |
|---|---|
| Refrigerant | R32 |
| Liquid pipe | 6.35 mm (1/4 in), 0.8 mm wall thickness |
| Gas pipe | 12.70 mm (1/2 in), 0.8 mm wall thickness |
| Maximum pipe length | 30 m |
| Maximum height difference | 20 m |
| Factory charge allowance | Up to 20 m |
| Additional charge | 20 g/m above 20 m; +100 g at 25 m and +200 g at 30 m |
| Maximum charge | 1,470 g |
| Cooling range | -10°C to 46°C |
| Heating range | -15°C to 24°C |
| Power cable - model 18 | 2.5 mm², 2 conductors plus earth |
| Power cable - models 22/24 | 4.0 mm², 2 conductors plus earth |
| Interconnection cable | 1.5-2.5 mm², 3 conductors plus earth |
| Breaker | 16 A model 18; 20 A models 22/24; 30 mA earth leakage protection |
2. Indoor-unit installation
| Clearance | Minimum |
|---|---|
| Above unit | 84 mm |
| Left side | 127 mm |
| Right side | 133 mm |
| Front | 1,500 mm |
| Floor to unit | 1,800 mm |
| Remote range | Maximum 7 m |
Human sensor: Approximate detection range is 7 m, 90° vertically and 100° horizontally.
Six piping directions
Rear, right, bottom, left-bottom, left and left-rear.
- Mount the wall bracket level using at least five screws.
- Cut a 65 mm wall hole with the outside edge 5-10 mm lower.
- Always install a wall pipe and wall cap.
- For left-side piping, transfer the drain hose and drain cap and refit the retaining screw.
- Keep the drain hose below the refrigerant pipes and maintain continuous fall.
- Engage the top hooks first, then press the lower fittings onto the bottom hooks.
Drainage: Do not lift the drain hose, create waves or submerge the end. Apply freeze protection where the hose may be exposed below 0°C.
3. Indoor flareless joint connection
Use clean, straight pipe ends. Do not use pipe with scratches, dents, deformation or bends within 30 mm of the pipe end. Cut square and deburr carefully.
| Pipe | Insertion mark from pipe end | Tightening torque |
|---|---|---|
| 6.35 mm | 22 mm | 16-18 N·m |
| 12.70 mm | 27 mm | 49-61 N·m |
| 1 | Mark the insertion depth on the connection pipe: 22 mm for 1/4 in and 27 mm for 1/2 in. |
| 2 | Peel the seal from the tightening nut. |
| 3 | Insert the pipe until it contacts the indoor-unit joint. If required, loosen the tightening nut by half a turn only to permit insertion. |
| 4 | Hand-tighten the nut to temporarily secure the pipe. |
| 5 | Hold the indoor body-side coupling with a spanner and tighten the hexagonal nut with a torque wrench. |
| 6 | Confirm the insertion mark is within 1 mm of the tightening nut. |
Reject and replace: If the insertion mark is more than 1 mm from the nut, remove and replace the flareless joint nut assembly and repeat the procedure. If the assembly has been loosened after final tightening, it must also be replaced.
4. Outdoor-unit installation
| Side | Minimum |
|---|---|
| Rear | 100 mm |
| Left | 100 mm |
| Right | 250 mm |
| Front | 200 mm |
| Above | 600 mm |
| Below | 50 mm |
- Mount on a strong stand and do not install directly on the ground.
- Keep the unit within 5° of level and secure against strong wind.
- Keep at least three horizontal directions open where possible.
- Do not use the drain pipe or drain caps where outdoor temperature may be 0°C or lower.
- Raise the unit and provide snow protection in heavy-snow areas.
5. Outdoor flare connections
| Pipe | Torque |
|---|---|
| 6.35 mm | 16-18 N·m |
| 12.70 mm | 49-61 N·m |
Use R32/R410A-compatible tools. Bend pipes at a radius of at least 70 mm and do not bend the same location more than three times.
6. Evacuation and charging
Do not purge with refrigerant. Use a clean R32/R410A vacuum pump and manifold.
- Confirm the service valves are fully closed.
- Connect the manifold to the 3-way-valve charging port.
- Evacuate for at least 15 minutes and achieve -0.1 MPa / -76 cmHg.
- Close the low-side valve and stop the vacuum pump.
- Crack the 3-way valve until pressure reaches approximately 0.1-0.2 MPa, then disconnect the hose.
- Fully open both service valves.
- For pipework above 20 m, add liquid R32 by electronic scale at 20 g/m.
- Leak-test all refrigerant joints before commissioning.
| Cap | Torque |
|---|---|
| 1/4 in blank cap | 20-25 N·m |
| 1/2 in blank cap | 28-32 N·m |
| Charging-port cap | 12.5-16 N·m |
7. Electrical wiring
Match terminals 1, 2 and 3 between indoor and outdoor units and connect protective earth. Clamp cables by the outer sheath.
| Screw | Torque |
|---|---|
| M3.5 | 0.8-1.0 N·m |
| M4 | 1.2-1.8 N·m |
| M5 | 2.0-3.0 N·m |
Route demand-control wiring away from power and interconnection cables to prevent electrical noise and malfunction.
8. Test run and commissioning
Hold MANUAL AUTO for more than 10 seconds to begin forced cooling. The OPERATION and TIMER lamps flash together. Select HEAT on the remote for a heating test. End using START/STOP.
| Commissioning check | Done |
|---|---|
| Indoor flareless insertion marks within 1 mm of nuts | ☐ |
| Outdoor flare joints leak-tested | ☐ |
| Drainage test completed | ☐ |
| Remote, lamps and louvres operate correctly | ☐ |
| No abnormal noise or vibration | ☐ |
| Additional charge recorded where applicable | ☐ |
| Customer shown operation and filter maintenance | ☐ |
9. Optional controls
| Option | Reference |
|---|---|
| Wired remote controller | UTY-RVNYN / UTY-RNNYN; UTY-TWBXF1 communication kit required |
| Simple remote controller | UTY-RSNYN; communication kit required |
| External connect kit | UTY-XWZXZ5 |
| Communication kit | UTY-TWBXF1 |
Based on Fujitsu General indoor installation manual Part No. 9320456009 and outdoor installation manual Part No. 9320394004-02. This simplified field reference does not replace the complete manuals, rating labels or current Australian and New Zealand regulations.