Fujitsu General NZ Assist

Applies to (as covered by attached manuals):
Indoor (Ducted): ARTH18KMTAP / ARTH24KMTAP / ARTH30KMTAP / ARTH36KMTAP / ARTH45KMTAP / ARTH54KMTAP
Outdoor (Single type): AOTH30KBTA / AOTH36KBTA / AOTH45KBTA / AOTH54KBTA
Outdoor (Single type): AOTH24KCTA / AOTH30KCTA
Wall Controller (Wired): UTY-RNRT (UI / error-display guidance aligned to UTY-RNR family)
Optional parts referenced: Air filter kit UTD-LFDA / UTD-LFDB
Refrigerant: R32
Audience: Authorised service personnel / professional installers

Contents

• 1) Safety and compliance
• 2) R32 refrigerant requirements
• 3) Tools and materials (R32/R410A rated)
• 4) System overview (power, control, commissioning flow)
• 5) Refrigerant piping requirements
• 6) Electrical requirements
• 7) Outdoor unit installation
• 8) Indoor unit installation
• 9) Pressure test, evacuation, commissioning
• 10) Additional refrigerant charging
• 11) Indoor function settings
• 12) Test run and handover
• 13) Pump down (forced cooling operation)
• 14) Error codes (indoor/outdoor consolidated)
• 15) UTY-RNRT specific error displays

1) Safety and compliance

• Installation, electrical work, and commissioning must be performed by qualified and experienced personnel in accordance with applicable standards and local regulations.
• Do not energise the system until all installation work is complete, covers are fitted, and terminals are verified correct and secure.
• After isolating power, wait for component discharge before touching electrical parts.
• If refrigerant leakage occurs during works: ventilate immediately, remove ignition sources, and implement spill/leak response procedures suitable for A2L refrigerants.
• Use vacuum pump evacuation; do not purge with refrigerant.
• Ensure correct grounding/earthing, appropriate overcurrent protection, and earth leakage protection as required by local regulations.
• Do not touch aluminium heat exchanger fins; handle equipment to prevent sharp-edge injury and property damage.

2) R32 refrigerant requirements

• R32 is an A2L refrigerant (mildly flammable). Implement ignition control, adequate ventilation, and leak detection practices consistent with flammable refrigerant requirements.
• R32 operates at higher pressures than legacy refrigerants. Use only R32/R410A-rated tools, hoses, and materials.
• Charging port thread for R32/R410A service ports: 1/2–20 UNF.
• Prevent moisture/foreign matter entering piping; cap/seal pipe ends during storage/handling and between process steps.
• Leak detection must be suitable for flammable refrigerants; do not use open flame methods.
• Use approved recovery methods and cylinders for refrigerant removal, relocation, or end-of-life service activities.

3) Tools and materials (R32/R410A rated)

• High-pressure gauge manifold suitable for R32/R410A
• R32/R410A charging hoses (compatible seals and pressure rating)
• Vacuum pump (recommended with check valve) and appropriate adapters
• Electronic refrigerant scale (for accurate charging by mass)
• R32/R410A compatible leak detector (A2L suitable)
• Tube cutter, deburr tool, flare tool suitable for R32/R410A, flare gauge (as required)
• Torque wrenches for flare nuts, service valves, and caps
• Nitrogen cylinder + regulator (for pressure testing / strength & tightness test)
• Insulation (liquid and gas), UV/impact protection where exposed, and sealing putty for penetrations

4) System overview (power, control, commissioning flow)

4.1 Power and control architecture (typical)

• Outdoor unit: Main supply connected to the outdoor unit disconnect/isolator.
• Indoor unit: Powered and controlled per model wiring design (verify terminals and interconnect design for the job). Do not connect AC supply to transmission terminals.
• Wired controller (UTY-RNRT): Connect to indoor controller terminals per indoor wiring diagram. Observe polarity requirements if specified by the indoor unit (many Fujitsu wired controllers are non-polar on the communication pair, however you must follow the indoor unit terminal marking).

4.2 Recommended commissioning workflow (governance flow)

• Mechanical installation complete (mounting, duct/drain, piping run, insulation)
• Electrical installation complete (power, interconnect, controller wiring, terminations verified)
• Pressure test (nitrogen) with outdoor service valves closed
• Evacuation (vacuum) to required level and hold test
• Open service valves fully, refit caps to torque
• Additional charge if piping exceeds pre-charge length
• Indoor function settings (static pressure / control features)
• Test run and validation checks
• Handover and documentation completion

4.3 Controller & service interaction (operational controls)

• Use controller Status / Error Information to capture fault codes and unit address where applicable.
• Where outdoor display PCB is fitted, use the display unit buttons to view local settings and error display modes.
• For group control / multiple controller configurations, ensure addressing and system architecture is confirmed prior to commissioning (avoid duplicated addressing / mis-termination).

5) Refrigerant piping requirements

5.1 Copper pipe material and minimum wall thickness (R32/R410A)

• Use seamless phosphor deoxidised copper appropriate for R32/R410A applications.
• Do not reuse existing piping unless it is verified suitable for R32/R410A cleanliness, pressure rating, and condition (best practice: replace).

5.2 Line sizes (job verification)

• Verify the correct liquid and gas line sizes on the outdoor/indoor connection specifications for the exact model combination.
• Always insulate both liquid and gas lines. Increase insulation thickness in high humidity environments to prevent sweating.
• Protect pipe ends against moisture/dust entry during storage and installation.

5.3 Piping length limits (outdoor unit reference)

• Minimum piping length: 5 m
• Maximum height difference (Indoor → Outdoor): 30 m
• Maximum piping length (by outdoor series):
  • KBTA (AOTH30/36/45/54): 50 m
  • KCTA (AOTH24/30): follow model limits as specified for the KCTA series (installation must comply with the permissible length table for the exact model).

6) Electrical requirements

6.1 Outdoor unit power supply (AOTH)

• Voltage rating (model dependent): 1Φ 220–240 V (50 Hz) / 3Φ 380–415 V (50 Hz)
• Operating range: 1Φ 198–264 V / 3Φ 342–457 V
• Power supply cable (minimum reference):
  • Single phase: Min. 4 mm² (Type 60245 IEC 66), 2 cable + Earth (Ground)
  • Three phase: Min. 2.5 mm² (Type 60245 IEC 57), 4 cable + Earth (Ground)
• Breaker capacity / Earth leakage breaker (reference set): Select per model nameplate and local code; ensure adequate interrupt capacity and leakage protection as required.
• Install a disconnect device with a contact gap of at least 3 mm in all poles nearby the units (indoor and outdoor) as required by local regulations.

6.2 Indoor to outdoor connection cable

• Follow indoor unit wiring diagram for terminal assignments and conductor sizing.
• Limit voltage drop to less than 2%; increase conductor size if required.
• Do not connect AC supply to transmission terminals.

6.3 Wired controller (UTY-RNRT) wiring governance

• Route controller cable separately from mains power to reduce noise pickup and prevent nuisance communication faults.
• Terminate securely and confirm strain relief and cable protection at entry points.

7) Outdoor unit installation

7.1 Location and mounting

• Install on a base that can withstand weight and vibration; use anchor bolts and appropriate anti-vibration measures.
• Maintain required clearances for airflow and service access. Prevent discharge air recirculation.
• Do not install where combustible gas may accumulate or in corrosive environments.
• Secure appropriately for local wind/weather conditions.

7.2 Drain considerations (outdoor)

• Heating operation produces drain water; route to a suitable drain point where applicable.
• In freezing climates, apply appropriate freeze protection strategies per local best practice.

7.3 Outdoor display unit & buttons (operation / settings / error access)

7.4 Outdoor field settings (typical functions)

• Low noise mode: Configure via Local setting mode. Select and confirm the Low Noise mode level required for the site conditions.
• Peak cut: Configure via Local setting mode. Select the appropriate peak cut level where required by the electrical design / demand strategy.
• Auto restart: Configure as required by the job scope (power recovery behaviour).
• Governance note: Perform outdoor field settings after the indoor unit has stopped and prior to commissioning validation.

7.5 External input and output (integration readiness)

• External input can be used for interlocks and control strategies (job specific). Ensure correct signal type and wiring method.
• External output can be configured for status outputs (operation status, error status, fresh air control, auxiliary heater, etc.) where supported by the indoor unit configuration.

8) Indoor unit installation

8.1 Site selection and serviceability

• Install in a location that supports the unit mass and minimises vibration transmission.
• Ensure ducting, filter access, and condensate drain access are serviceable after installation.
• Ensure appropriate access for electrical service and refrigerant piping connections.

8.2 Ductwork and airflow management (critical)

• Confirm ductwork design external static pressure (ESP) aligns with unit capability and commissioning method.
• Seal duct joints to prevent air leakage and performance degradation.
• Confirm return air path and filter arrangement prevents debris ingress to the fan/coil.

8.3 Condensate drain

• Provide correct fall and trapping per local best practice to prevent blow-off and odours.
• Insulate condensate line where sweating may occur.
• Water-test drainage prior to ceiling closure / handover.

8.4 Optional part reference – Air filter kit (UTD-LFDA / UTD-LFDB)

• Bundle the two air filters together with the supplied cable tie (medium). The side bound with the cable tie is the bottom; the side with “PUSH” markings is the front.
• Fit each air filter to the 4 hooks on the indoor unit.
• After installation, configure the filter sign function setting as required (see Section 11).

9) Pressure test, evacuation, commissioning

9.1 Flare work – tightening torques (system)

9.2 Leak test (air tightness test)

• Perform an air tightness test using nitrogen while all outdoor unit valves are closed.
• Use a test pressure suitable for the equipment and do not exceed the value specified on the outdoor unit nameplate.
• Confirm all joints are leak-free prior to evacuation.

9.3 Vacuum evacuation

• Evacuate to –0.1 MPa (–76 cmHg).
• When –0.1 MPa is reached, operate the vacuum pump for at least 60 minutes.
• Perform a vacuum hold test to confirm no moisture/air ingress (pressure rise indicates leak or moisture).

9.4 Service valve / port cap torques (outdoor reference)

9.5 Final commissioning checks

• Open service valves fully after evacuation and before starting operation.
• Confirm correct power supply, correct interconnect wiring, correct controller wiring, and secure terminals.
• Confirm drainage is normal (water test) and insulation complete.
• Confirm no refrigerant leakage using an A2L compatible electronic leak detector.

10) Additional refrigerant charging

• Pre-charge length: 30 m
• If piping length exceeds 30 m, additional refrigerant is required.
• Charging guideline: 40 g/m beyond 30 m.
• Calculation: Additional charge (g) = (Actual piping length (m) – 30) × 40, for lengths > 30 m.
• Record factory (base) charge, additional charge, and total charge on the outdoor unit refrigerant label.

10.1 KBTA (AOTH30/36/45/54)

10.2 KCTA (AOTH24/30)

11) Indoor function settings

11.1 Governance notes

• Function settings change indoor unit control behaviour. Incorrect settings can cause malfunction, noise, water leakage, or comfort issues.
• After completing Function Setting, turn power off and back on to apply the settings.
• Record all changes in job documentation for service governance.

11.2 Setting record (functions used in this series)

• Function numbers commonly used for this ducted series include: 11 (Filter sign), 26 (Static pressure), 30/31 (Room temp control – indoor sensor cooling/heating), 35/36 (Room temp control – wired controller sensor cooling/heating), 40 (Auto restart), 42 (Room temp sensor switching), 43 (Cold air prevention), 46 (External input control), 48 (Room temp sensor switching (Aux.)), 49 (Indoor fan control for energy saving for cooling), 60 (External output function switching).

11.3 Static pressure setting (Function No. 26) – commissioning control

• Manual setting: Select the required Pa value where duct ESP is known.
• Automatic airflow adjustment: Use when commissioning requires automated fan calibration (ensure system complete and stable before initiation; not suitable where a booster fan is installed between ducts).

11.4 Indoor fan control for energy saving for cooling (Function No. 49)

11.5 External output function switching (Function No. 60)

12) Test run and handover

12.1 Pre-test run check items

• Controller operation and display status normal
• Indoor fan operation stable (no hunting / abnormal ramping)
• Airflow achieved and duct system balanced
• Drainage normal (no water leakage)
• No abnormal noise or vibration
• No refrigerant leakage detected

12.2 Customer guidance (handover governance)

• Explain controller operation, setpoints, timers/schedules (where applicable).
• Explain filter access/cleaning intervals and service requirements.
• Confirm any building management interface / external interlocks (if installed).
• Provide commissioning records, wiring schematics as installed, and refrigerant charge documentation.

13) Pump down (forced cooling operation)

• Use pump down for relocation/disposal refrigerant recovery in accordance with manufacturer procedure and local regulatory requirements.
• Initiate forced cooling / test run mode per controller guidance (method varies by controller type).
• Close the 2-way valve fully, then close the 3-way valve after the required run period, then stop operation.
• Do not proceed if refrigerant is depleted due to damaged piping; confirm leak-free condition first.
• Use the outdoor display unit PUMP DOWN button where provided to start the pump down operation sequence.

14) Error codes (indoor/outdoor consolidated)

Error codes may be displayed on the wired controller, or indicated via outdoor display unit error mode where fitted. Capture the code, confirm wiring/communication integrity, and follow standard diagnostic workflow (power, comms, sensors, loads, then control PCB).

15) UTY-RNRT specific error displays

These error displays are specific to UTY-RNRT wired remote controller system conditions (in addition to the consolidated system error code table above). Use the controller Status → Error Information screen to view error code and the affected address.

End of consolidated installation and commissioning solution.