1. Purpose and Function
The Network Converter enables single split and multi-split systems to be monitored and controlled through a VRF (Variable Refrigerant Flow) network.
It allows integration of RAC/PAC indoor units with the central VRF control platform for unified operation, monitoring, and maintenance
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.2. Model Variants
| Model | Type | Power Supply | Remote Controllers Supported | Use Case |
|---|---|---|---|---|
| UTY-VTGX | Plastic case | Supplied from indoor unit | 1 wired controller | Compact single controller use |
| UTY-VTGXV | Metal case | AC 208–240 V | Up to 2 wired controllers | For dual remote applications or larger systems network convertor |
Both models support 2-wire and 3-wire controller types and can connect up to 16 indoor units per converter and 100 converters per VRF system.
3. Key Features
Compact, lightweight design (VTGX = 43 × 117 × 140 mm, 250 g).
Direct connection to indoor units; no external DC power needed (VTGX).
Compatible with both 2-wire and 3-wire wired controllers.
Enables centralized control for non-VRF systems.
Simplified switch configuration (fewer DIP switches than the predecessor UTY-VGGXZ1).
Same PCB used across both models for service consistency
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4. Electrical and Wiring Overview
UTY-VTGX: Power supplied from indoor unit via K-terminal.
2-wire: Both indoor and RC cables connect to K-terminal.
3-wire: Indoor to K-terminal, RC to Y-terminal.
UTY-VTGXV: Power supplied from external AC 208–240 V.
Same terminal connection logic applies as VTGX.
Install indoors only; avoid bottom cable entry to prevent fire risk.
Switch Settings:
SET 1 – Refrigeration circuit address
SET 2-1 – Terminal resistance (ON for standalone converter networks)
SET 3 – 2-wire / 3-wire selection (Default = 2-wire)
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5. Connectable Equipment
Outdoor units: All current VRF series (non-discontinued models).
Indoor units: RAC/PAC units equipped with compatible wired controllers.
Remote controllers: UTY-RVNYM, UTY-RLRY, and other standard 2-wire/3-wire types.
Central controllers: System Controller, Touch Panel Controller (TPC), and Central Remote Controller (CRC)
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6. Available Functions
Central Control (System Controller/TPC/CRC):
ON/OFF, mode change, temperature setting, filter reset.
Local Control (Wired Remote):
ON/OFF, temperature, timer setting, fan speed.
Some functions (e.g., temperature-limit) behave as per VRF1 specification, allowing ± 2 °C range when “temperature limitation” is active on the central controller
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7. Simplified Configuration
Compared to the old UTY-VGGXZ1, six DIP switches were removed, minimizing setup time.
Automatic recognition of 2-wire RC addressing; manual addressing needed for 3-wire RCs.
Function setting from RC is available via 2-wire but not 3-wire connection
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8. Connection Verification
Prior to test run, confirm all intended converters appear in the Service Tool equipment list.
Model ID for UTY-VTGX/VTGXV displays similar to an indoor unit in the software interface
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9. Error Diagnostics
Diagnostic LEDs (LED1, LED2, LED3) indicate communication or connection faults.
Errors are converter-specific and must be cross-checked against the blink-code table in the manual.
If communication microcontrollers fail, replacement of the full PCB may be required (re-seating will not restore functionality)
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10. Installation Restrictions
Only one single-split or one multi-split system may be connected per converter.
Do not mix 2-wire and 3-wire remote controllers on a single converter.
Grouped single splits may share one converter, but multi-system connections are prohibited.
RC prohibition command from central controller only applies to wired RCs, not wireless RCs
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11. Training Clarifications (From Meeting Minutes)
Power limitations: VTGX cannot power two RCs because supply current is shared with the indoor unit.
Function limitation: Refers to command restrictions from central control.
Terminal resistance: Required when connecting PAC/RAC systems into VRF.
Cable Lengths:
2-wire total ≤ 500 m.
3-wire total ≤ 100 m (+ 100 m extension max).
Design Simulator: Both converter models supported via software auto-update since early 2016
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12. Summary
The UTY-VTGX and UTY-VTGXV Network Converters enable Fujitsu RAC/PAC indoor units to operate seamlessly under VRF central control, providing consistent monitoring, command, and system integration.
Key benefits include:
Simplified installation with auto power and address management.
Full compatibility with 2-wire / 3-wire RCs and central controllers.
Reliable communication through LON network with up to 100 converters per VRF system.
Streamlined service diagnostics with onboard LEDs and service-tool visibility.