Fujitsu General NZ Assist

Applies to:
Indoor (Ducted): ARTH24KHTA / ARTH30KHTA / ARTH36KHTA / ARTH45KHTA / ARTH54KHTA / ARTH60KHTA
Outdoor: AOTH24KBTA / AOTH30KBTA / AOTH36KBTA / AOTH45KBTA / AOTH54KBTA / AOTH45KCTA / AOTH54KCTA / AOTH60KCTA / AOTH60KBTA / AOTH60KRTA
Wired Controller: UTY-RNRT
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, and wiring)
• 5) Refrigerant piping requirements (pipe sizes, limits, and workmanship)
• 6) Electrical requirements (outdoor supply + indoor interconnect)
• 7) Outdoor unit installation (AOTH)
• 8) Indoor unit installation (ARTH ducted)
• 9) Pressure test, evacuation, commissioning
• 10) Refrigerant charge: base charge + additional charge calculations
• 11) Indoor function settings (ARTH) incl. static pressure
• 12) Wired controller (UTY-RNRT) function setting workflow
• 13) Outdoor function settings (AOTH): Low Noise + Peak Cut
• 14) Test run and handover
• 15) Pump down (forced cooling operation)
• 16) Error codes (Indoor / Outdoor / Controller)

1) Safety and compliance

• Installation and servicing must be completed by qualified and experienced personnel only.
• Do not energise the system until all installation work is complete and covers are refitted.
• After isolating power, wait before touching electrical components (observe manufacturer discharge guidance).
• If refrigerant leakage occurs during works: ventilate immediately and remove ignition sources.
• Use vacuum pump evacuation (do not purge with refrigerant).
• Ensure correct grounding/earthing and earth leakage protection as required by local regulations.

2) R32 refrigerant requirements

• Only use R32/R410A-rated tools, hoses, flare tools, and gauges.
• Charging port thread for R32/R410A: 1/2–20 UNF.
• Prevent moisture/foreign matter entering piping; seal pipe ends during storage/handling.
• Leak detection must be suitable for flammable refrigerants; do not use open flame methods.

3) Tools and materials (R32/R410A rated)

• High-pressure gauge manifold suitable for R32/R410A
• R32/R410A charging hoses
• Vacuum pump and appropriate adapters (as required)
• R32/R410A compatible leak detector
• Tube cutter, deburr tool, flare tool suitable for R32/R410A, torque wrenches for flare nuts and caps
• Nitrogen cylinder + regulator for pressure testing
• Accurate digital scales for additional charging

4) System overview (power, control, and wiring)

• Follow the unit wiring diagrams and terminal designations. Confirm terminal numbering matches at both ends.
• Limit voltage drop to < 2% across supply and interconnect; increase conductor size if required.
• Do not route control / transmission wiring in contact with refrigerant piping or sharp edges.

5) Refrigerant piping requirements (pipe sizes, limits, and workmanship)

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

• Use seamless phosphor deoxidised copper.
• Do not reuse existing piping (risk of contamination and incompatibility).

5.2 Line sizes (by outdoor model group)

• AOTH24KBTA:
  • 09 / 12: Liquid 6.35 mm (1/4") / Gas 9.52 mm (3/8")
  • 18 / 24: Liquid 6.35 mm (1/4") / Gas 12.70 mm (1/2")
• AOTH30/36/45/54KBTA: Liquid 9.52 mm (3/8") / Gas 15.88 mm (5/8")
• AOTH45/54/60KCTA + AOTH60KBTA + AOTH60KRTA: Liquid 9.52 mm (3/8") / Gas 15.88 mm (5/8")

5.3 Allowable piping length / height difference (use outdoor model limits)

• Always insulate both liquid and gas lines. Increase insulation thickness in high humidity environments.
• Protect piping ends from moisture and dust (pinch and/or tape ends during storage and installation).

6) Electrical requirements (outdoor supply + indoor interconnect)

6.1 AOTH24KBTA group (09 / 12 / 18 / 24)

• Supply: 1Φ 220–240 V ~ 50 Hz, operating range 198–264 V
• Power supply cable (selected sample):
  • 09 / 12 / 18: 1.5 mm², Type 60245 IEC57, 2-wire + Earth
  • 24: 2.5 mm², Type 60245 IEC57, 2-wire + Earth
• Breaker / ELCB (selected sample):
  • 09: 10 A, ELCB 30 mA
  • 12 / 18: 16 A, ELCB 30 mA
  • 24: 20 A, ELCB 30 mA
• Demand control signal transmission cable (if utilised): 0.5–1.5 (per AS/NZS 5000.2), double insulated, max length 30 m

6.2 AOTH30/36/45/54KBTA group

• Supply: 1Φ 220–240 V ~ 50 Hz, operating range 198–264 V
• Power supply cable (selected sample): Min. 4 mm², Type 60245 IEC66, 2 cable + Earth
• Breaker / ELCB (selected sample):
  • 30 / 36: 25 A, ELCB 30 mA
  • 45 / 54: 32 A, ELCB 30 mA
• Power supply impedance requirement: 0.419 Ω and below

6.3 AOTH45/54/60KCTA + AOTH60KBTA + AOTH60KRTA group

• Voltage rating:
  • 1Φ 220–240 V ~ 50 Hz (operating range 198–264 V)
  • 3Φ 380–415 V ~ 50 Hz (operating range 342–457 V)
• Power supply cable (selected sample):
  • Single phase: Min. 4 mm², Type 60245 IEC66, 2 cable + Earth
  • Three phase: Min. 2.5 mm², Type 60245 IEC57, 4 cable + Earth
• Breaker / ELCB (selected sample):
  • 45 / 54 / 60 (Single): 32 A, ELCB 30 mA
  • 60 (Three): 16 A, ELCB 30 mA
• Power supply impedance requirement: 0.428 Ω and below

6.4 Indoor ↔ Outdoor connection cable

• Outdoor manuals specify: Refer to the indoor unit installation manual for the connection cable specifications.
• Good practice requirements:
  • Limit voltage drop to < 2%; increase conductor size where necessary.
  • Maintain segregation from refrigerant pipework, sharp edges, and high temperature surfaces.

7) Outdoor unit installation (AOTH)

• Install on a base that can withstand unit weight and vibration; use anchor bolts and suitable anti-vibration control.
• Maintain required service clearances per the outdoor installation diagrams.
• Do not install where combustible gas may accumulate, or in corrosive environments.

8) Indoor unit installation (ARTH ducted)

• Confirm the installation environment meets R32 minimum room area / ventilation requirements where applicable.
• Support the indoor unit with suitable structure, vibration isolation, and service access.
• Insulate all condensate piping and confirm fall to drain, with trap/venting as required by local practice.

9) Pressure test, evacuation, commissioning

9.1 Flare work – tightening torques (R32/R410A)

9.2 Nitrogen pressure test

• With service valves closed, pressurise with nitrogen to 4.15 MPa.
• Check all flare joints and brazed points; rectify leakage and repeat test as required.

9.3 Vacuum evacuation

• Evacuate to -0.1 MPa (-76 cmHg) and run vacuum pump for at least 15 minutes (increase time for long pipe runs).
• After evacuation, open service valves and refit caps to specified torques.

9.4 Service valve / port cap torques

10) Refrigerant charge: base charge + additional charge calculations

• Always record refrigerant charge on the outdoor unit label:
  • Factory charge (refer to rating label)
  • Additional charge (calculated below)
  • Total charge (Factory + Additional)

10.1 AOTH24KBTA group (09 / 12 / 18 / 24)

• Factory charge covers:
  • 09 / 12: 15 m
  • 18 / 24: 20 m
• Additional charge rate guideline: 20 g/m beyond pre-charge length (up to maximum allowable length).

Maximum total charge (AOTH24KBTA group)

• 09 / 12: 950 g (850 g + 100 g)
• 18: 1220 g (1020 g + 200 g)
• 24: 1450 g (1250 g + 200 g)

10.2 AOTH30/36/45/54KBTA group

• Pre-charge length: 30 m
• Additional charge rate: 40 g/m beyond 30 m

Maximum total charge (AOTH30/36/45/54KBTA group)

• 30 / 36: 2700 g (1900 g + 800 g)
• 45 / 54: 3500 g (2700 g + 800 g)

10.3 AOTH45/54/60KCTA + AOTH60KBTA + AOTH60KRTA group

• Pre-charge length: 30 m
• Additional charge rate: 40 g/m beyond 30 m

Model: AOTH60KBTA / AOTH60KRTA

Model: AOTH45KCTA / AOTH54KCTA / AOTH60KCTA

Maximum total charge (AOTH45/54/60KCTA + AOTH60KBTA/KRTA group)

• 60KBTA / 60KRTA: 4200 g (with piping length 50 m)
• 45KCTA: 5200 g (with piping length 75 m)
• 54KCTA / 60KCTA: 5600 g (with piping length 75 m)

11) Indoor function settings (ARTH) incl. static pressure

• Function settings are applied via the controller function setting workflow (see Section 12).
• After completing function settings, power-cycle the system in line with safe isolation practices.

11.1 Function details (common)

11.2 Static pressure setting (Function 26)

ARTH24/30/36KHTA (range: 60–210 Pa)

ARTH45/54/60KHTA (range: 60–260 Pa)

12) Wired controller (UTY-RNRT) function setting workflow

• Confirm wiring and covers are complete before entering function setting mode.
• Enter function setting mode on the wired controller:
  • Press and hold FAN and TEMP (▲) simultaneously, then press RESET.
• Change function number using TEMP (▲/▼).
• Change setting value using FAN.
• Confirm using MODE, then apply using START/STOP.
• To cancel or exit: press RESET.

13) Outdoor function settings (AOTH): Low Noise + Peak Cut

• Outdoor models provide on-board function settings for capacity limitation (Peak Cut) and noise reduction (Low Noise).
• Use these settings to align operation with site constraints (e.g., supply limitation, acoustic restrictions) while understanding that performance will be reduced.

13.1 Peak Cut mode – level indication (L4/L5/L6)

Peak Cut level is indicated by the lamp pattern (L4/L5/L6):

14) Test run and handover

• Confirm correct supply voltage, wiring polarity/terminal numbering, earth continuity, and covers fitted.
• Confirm no refrigerant leaks, normal condensate drainage, and no abnormal noise/vibration.
• Complete operational verification in cooling and heating (where applicable), including controller functionality.
• Provide end-user guidance on operation, maintenance access, and filter cleaning interval.

15) Pump down (forced cooling operation)

• Use pump down for relocation/disposal refrigerant recovery in accordance with local regulations and manufacturer procedure.
• General sequence:
  • Start forced cooling / service operation.
  • Close the liquid (2-way) valve fully.
  • After a short run period, close the gas (3-way) valve, then stop operation.
  • Do not proceed if refrigerant has been depleted due to damaged piping; confirm leak-free condition first.

16) Error codes (Indoor / Outdoor / Controller)

16.1 Indoor/Outdoor system error codes (displayed via controller / service diagnostics)

• Use the indoor unit diagnostic workflow and error display reference for ARTH systems.
• Where outdoor models support LED-based error check (Section 16.2), use that method when no controller display is available.

16.2 Outdoor unit (AOTH) – error check table (LED based)

• Outdoor models include an LED-based error check capability. Enter error display mode per outdoor service procedure, then interpret the lamp pattern.
• Record the lamp pattern as observed (L1–L6) before isolating power for troubleshooting.

16.3 Wired controller (UTY-RNRT) – controller-specific indications

• UTY-RNRT supports function setting mode for indoor function configuration (Section 12) and will display system error conditions provided by the connected indoor/outdoor system.
• If the controller indicates a communication/configuration fault condition, verify controller wiring, polarity/terminal numbering, and address/configuration settings.

Operational governance: This article is intended to consolidate installation-critical parameters (electrical, refrigerant charging, commissioning, function settings). Always execute works in accordance with applicable standards, local regulations, and site risk controls.