Overview
The Fujitsu ARTC90LATU ducted unit is equipped with several external input and output terminals that allow remote operation and signal monitoring.
These terminals enable integration with external systems such as building management systems (BMS), fans, heaters, and status indicator displays.
This guide outlines the available terminals, wiring details, and signal behavior for each function.
1. External Input & Output Summary
| Function | Type | Connector | Remarks |
|---|---|---|---|
| Control Input (Operation/Stop) | Input | CN103 | Allows remote ON/OFF control |
| Operation Status | Output | CN100 | Indicates unit operation status |
| Error Status | Output | CN101 | Outputs fault/error condition |
| Fresh Air Control | Output | CN161 | Triggers external fresh air fan control |
| Auxiliary Heater | Output | CN160 | Activates external heater during heating mode |
(Reference: page 1 of the manual)
ARTC90LATU input output
2. Control Input (Operation / Stop)
Description
Allows the air conditioner to be started or stopped remotely using an external ON/OFF signal (e.g., wall switch, BMS contact).
When switched ON, the unit begins operation with the following startup parameters:
| Condition | Setting |
|---|---|
| Operation Mode | Auto Changeover |
| Set Temperature | 24 °C |
| Airflow Mode | Auto |
(Subsequent startups restore the previous operation settings.)
Connection Details
Connector: CN103 on indoor control PCB
Contact capacity: 5 V DC, 15 mA or higher
Maximum wiring length: 10 m
Use non-polar relays and switches
Field supply wire: UTD-ECS5A (optional)
Signal Behavior
| Input Signal | Unit Operation |
|---|---|
| ON | Operation |
| OFF | Stop |
(See wiring example on page 1 diagram.)
ARTC90LATU input output
3. Operation Status Output
Description
Provides an external signal indicating whether the indoor unit is operating or stopped.
This can be connected to a display lamp, relay unit, or monitoring device.
Connection Details
Connector: CN100 on indoor control PCB
Output voltage: 24 V DC max
Load: 10 mA – 500 mA max
Maximum cable length: 10 m
Use optional cable: UTD-ECS5A
Signal Behavior
| Unit Status | Output Signal |
|---|---|
| Operating | ON |
| Stopped | OFF |
(See page 2 for wiring diagram example.)
ARTC90LATU input output
4. Error Status Output
Description
Outputs a status signal when the indoor unit enters a fault or error condition.
Used for remote monitoring or alarm indication systems.
Connection Details
Connector: CN101 on indoor control PCB
Output voltage: 24 V DC max
Load: 10 mA – 500 mA max
Maximum cable length: 10 m
Optional wire: UTD-ECS5A
Signal Behavior
| Error Status | Output Signal |
|---|---|
| Normal | OFF |
| Error Detected | ON |
(Refer to page 3 circuit example.)
ARTC90LATU input output
5. Fresh Air Control Output
Description
Provides an output signal to control an external fresh air fan linked with indoor fan operation.
This allows coordinated control for ventilation systems.
⚠️ Note:
The signal switches OFF during cold-air prevention control in heating operation.
Connection Details
Connector: CN161
Output voltage: 12 V DC (rated)
Load: 50 mA or less
Relay rating: 12 V DC / 50 mA or less
Maximum distance: 10 m
Optional wire: UTD-ECS5A
Signal Behavior
| Indoor Fan Operation | Output Signal |
|---|---|
| Fan ON | ON |
| Fan OFF | OFF |
(Refer to page 4 for detailed circuit layout.)
ARTC90LATU input output
6. Auxiliary Heater Output
Description
Activates an external heater during heating operation.
The signal is synchronized with the compressor and indoor fan operation to prevent cold air discharge.
Operation Logic
ON: When heating starts (compressor and indoor fan ON)
OFF: When room temperature reaches the setpoint or rises above by +1 °C
OFF: When room temperature drops 10 °C below setpoint (safety condition)
Connection Details
Connector: CN160
Output voltage: 12 V DC max
Load: 50 mA or less
Relay specification: 12 V DC / 50 mA or less
Distance: within 10 m
Optional cable: UTD-ECS5A
Fan Delay (Jumper Wire Setting)
The indoor fan can be configured to run for 1 minute after the thermostat turns OFF in heating mode.
This delay is enabled by cutting the jumper wire on the PCB.
Caution
Always install the external heater between the indoor unit and ductwork, not directly inside the indoor cabinet.
Use fan delay control to prevent overheating or airflow imbalance.
(See wiring and timing diagram on page 5.)
ARTC90LATU input output
7. Summary Table
| Connector | Function | Signal Type | Typical Application |
|---|---|---|---|
| CN103 | Control Input (Start/Stop) | Input | Remote switch / BMS signal |
| CN100 | Operation Status | Output | System monitoring |
| CN101 | Error Status | Output | Alarm signal |
| CN161 | Fresh Air Control | Output | External fan operation |
| CN160 | Auxiliary Heater | Output | Heater activation |
8. Key Takeaways
All external signals are low-voltage DC (5 V – 24 V DC).
Maintain a maximum wiring distance of 10 m between the PCB and connected unit.
Always use non-polar relays and optional Fujitsu harnesses (UTD-ECS5A).
Ensure correct fan delay control when using an external heater to avoid thermal stress.
Signals are ideal for integration into BMS or control automation systems.
Support
For wiring diagrams, configuration assistance, or troubleshooting:
? Fujitsu Assist Technical Support: 1300 364 484 or +64 4 568 8761 NZ