General Assist Technical Reference
UTY-RNNYN Wired Remote Controller
Installation, wiring, function settings and diagnostics
Installation Manual Part No. 9373328155
The UTY-RNNYN is a legacy 3-wire wired remote controller for selected Fujitsu General and General indoor units. It supports room-temperature sensing, function setting, group control, dual-controller operation, test mode and fault-code display.
Compatibility must be confirmed: This is a polarised 3-wire controller using 12 V, Signal and COM. Do not connect it to a 2-wire controller terminal, the indoor/outdoor power terminal block or the outdoor unit.
1. Safety and installation requirements
| 1 | Installation must be completed by authorised personnel in accordance with national wiring requirements. |
| 2 | Do not energise the air conditioner until controller installation and wiring are complete. |
| 3 | Do not touch the remote-controller PCB or electronic components directly. |
| 4 | Keep the remote-controller cable separated from power, transmission and indoor/outdoor connection cables. |
| 5 | Use shielded cable near electromagnetic interference sources and ground the shield in accordance with the applicable installation design. |
Controller location
- Install where the average occupied-room temperature can be sensed.
- Avoid direct supply air from the indoor unit.
- Avoid direct sunlight and nearby heat sources.
- Avoid external walls where wall temperature differs substantially from room air.
- Maintain access for operation, service and removal of the front case.
Controller dimensions
| Width | 120 mm |
| Height | 120 mm |
| Depth | 18 mm |
2. Electrical and wiring requirements
| Terminal | Wire colour | Function |
|---|
| 1 | Red | 12 V |
| 2 | White | Signal |
| 3 | Black | COM |
| Recommended cable | 22 AWG, sheathed PVC, polar 3-core; shielded where required by local rules |
| Controller terminal strip length | Approximately 7 mm conductor exposure |
| Wall-mounted connector splice | Strip approximately 20 mm and join Red-to-Red, White-to-White and Black-to-Black |
Critical warning: Never connect the UTY-RNNYN cable to the outdoor-unit terminals or the indoor-unit power/interconnection terminal block. Use only the dedicated controller connector or controller terminal block identified in the indoor-unit installation manual.
Connection methods
| Method | Application |
|---|
| Supplied connecting cable | Commonly used on compatible wall-mounted indoor units. Insulate the cable splice completely. |
| Optional communication kit | Required on selected indoor units where the controller cannot connect directly to the indoor PCB. |
| Dedicated indoor terminal block | Connect terminals 1, 2 and 3 directly to the dedicated controller terminal block. |
3. DIP-switch settings
| DIP 1 number | Purpose | Required setting |
|---|
| 1 | Reserved | Do not change |
| 2 | Dual-controller master/slave selection | OFF for master; ON for slave |
| 3 | Filter reset and filter display validity | Set according to the required function setting |
| 4 | Reserved | Do not change |
| 5 | Reserved | Do not change |
| 6 | Memory backup | ON |
DIP 1-6 must be ON where battery memory backup is required. With backup disabled, stored settings may be lost after a power failure.
4. Group control and dual remote controllers
Group control
- One UTY-RNNYN can operate multiple compatible indoor units.
- Group control is generally available on ducted, cassette and ceiling indoor units, subject to model compatibility.
- Each indoor unit requires a unique indoor-unit address set at the indoor PCB.
- Some functions may become unavailable when different indoor-unit types are grouped.
- Maintain correct terminal polarity across every indoor unit.
Dual remote control
| Controller | DIP 1-2 | Capability |
|---|
| Master | OFF | Normal operation, timer and self-diagnosis |
| Slave | ON | Basic operation only; timer and self-diagnosis unavailable |
5. Power-up and temperature-sensor selection
Power-up checks
- Recheck controller wiring and DIP-switch settings.
- Reconnect the front-case plug and refit the controller front case.
- Confirm indoor and outdoor wiring and PCB settings.
- Apply power. The display will initialise and then show the clock screen.
Room-temperature detection
| Option | Function setting | Control method |
|---|
| Indoor-unit sensor | 42-00 | Room temperature is detected by the indoor-unit sensor. |
| Selectable indoor or controller sensor | 42-01 | Hold the ECONOMY / THERMO SENSOR button for at least 5 seconds to select the active sensor. |
| Both sensors | 48-00 | Control uses both indoor-unit and wired-controller sensors. |
| Controller sensor only | 48-01 | Control uses only the wired-controller sensor where supported. |
A controller mounted on a cold external wall or near a heat source can produce inaccurate room control. Confirm the sensed temperature against the occupied space before selecting the remote-controller sensor.
6. Entering function-setting mode
| 1 | Hold both SET TEMP buttons and FAN simultaneously for more than 5 seconds. |
| 2 | Press SET BACK to select the indoor-unit number. |
| 3 | Use the timer left/right buttons to select the function number. |
| 4 | Use the SET TEMP buttons to select the setting value. |
| 5 | Hold TIMER SET until the setting value stops flashing. |
| 6 | Repeat as required, then exit using the original three-button combination. |
| 7 | Power-cycle the system after completing all function settings. |
Common function settings
| Function | No. | Settings |
|---|
| Filter sign | 11 | 00 standard, 01 long, 02 short, 03 no indication |
| Ceiling height | 20 | 00 standard 2.7 m, 01 high ceiling 3.0 m |
| Outlet direction | 22 | 00 four-way, 01 three-way |
| Cooling temperature correction | 30 | 00 standard, 01 slightly lower, 02 lower, 03 warmer |
| Heating temperature correction | 31 | 00 standard, 01 lower, 02 slightly warmer, 03 warmer |
| Auto restart | 40 | 00 enabled, 01 disabled |
| Sensor switching | 42 | 00 indoor sensor only, 01 enable controller-sensor selection |
| Signal code | 44 | 00 A, 01 B, 02 C, 03 D |
| External input control | 46 | 00 Operation/Stop, 01 prohibited, 02 Forced Stop |
| Room control method | 48 | 00 both sensors, 01 controller sensor only |
Function availability and valid setting values depend on the connected indoor unit. A display of “--” or a value that does not save usually indicates an invalid setting for that indoor model.
7. Test operation
- Stop normal operation using START/STOP.
- Press FAN and MODE simultaneously for more than 2 seconds.
- The operation lamp illuminates and TEST appears on the display.
- Test operation runs for up to 60 minutes.
- Press START/STOP to end test operation.
Test mode does not override all safety protections. If the unit does not operate, check system conditions, addressing, wiring and current fault codes.
8. Wired-controller error codes
| Code | Description | Code | Description |
|---|
| 11 | Serial communication error | 12 | Wired-controller communication error |
| 15 | Check run unfinished | 21 | Unit or refrigerant address error |
| 22 | Indoor capacity error | 23 | Combination error |
| 24 | Connection-unit number error | 27 | Master/slave setup error |
| 32 | Indoor PCB model information error | 35 | Manual-auto switch error |
| 41 | Inlet-air temperature sensor error | 42 | Indoor heat-exchanger sensor error |
| 51 | Indoor fan motor error | 53 | Drain pump error |
| 57 | Damper error | 5U | Indoor-unit error |
| 62 | Outdoor main-PCB model or communication error | 63 | Inverter error |
| 64 | Active-filter / PFC error | 65 | Trip terminal L error |
| 6A | Display-PCB communication error | 71 | Discharge sensor error |
| 72 | Compressor sensor error | 73 | Outdoor heat-exchanger liquid sensor error |
| 74 | Outdoor-air sensor error | 75 | Suction-gas sensor error |
| 76 | 2-way / 3-way valve sensor error | 77 | Heat-sink sensor error |
| 82 | Sub-cool heat-exchanger sensor error | 83 | Liquid-pipe sensor error |
| 84 | Current sensor error | 86 | Pressure sensor / high-pressure switch error |
| 94 | Trip detection | 95 | Compressor rotor-position detection error |
| 97 | Outdoor fan motor error | 99 | 4-way valve error |
| A1 | Discharge temperature error | A3 | Compressor temperature error |
| A4 | High-pressure error | A5 | Low-pressure error |
| J2 | Branch-box error | | |
9. Commissioning checklist
| Check | Done |
|---|
| Exact indoor-unit compatibility confirmed | ☐ |
| Red, White and Black polarity confirmed | ☐ |
| Controller cable separated from power wiring | ☐ |
| DIP 1-6 set ON | ☐ |
| Master/slave DIP setting confirmed where two controllers are installed | ☐ |
| Indoor addresses confirmed for group control | ☐ |
| Room sensor selection tested | ☐ |
| Function-setting changes recorded and power cycled | ☐ |
| Test operation completed | ☐ |
Based on Fujitsu General UTY-RNNYN Wired Remote Controller Installation Manual, Part No. 9373328155. This field guide does not replace the connected indoor-unit installation manual or model-specific function-setting documentation.
