Fujitsu General Australia

Overview

The AIRSTAGE VRF External Input/Output Handbook provides a comprehensive guide to integrating additional control and monitoring features into Fujitsu VRF systems. These features enable advanced functionality such as energy saving, comfort enhancement, remote monitoring, and cold climate protection, all through external input/output terminals on indoor and outdoor units.

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1. Energy-Saving Functions

Automatic Off Function

• Uses a human presence sensor to automatically turn off indoor units when rooms are unoccupied (e.g., meeting rooms, lounges).

• Controlled via external connect kit UTY-XWZXZD connected to indoor unit terminal CNA02.

• Prevents unnecessary operation and reduces energy consumption.

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Peak Cut Power Consumption Function

• Limits system capacity between 40%–100% to reduce overall building power consumption.

• Activated by a manual switch or building management signal.

• Configured via external connect kit UTY-XWZXZ6 connected to outdoor unit terminal CN133.

• Ideal for commercial buildings with fluctuating loads (e.g., glass façades, factories).

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Keycard Interlocked Operation Function

• Synchronizes air conditioner operation with hotel keycard systems—turns units off when keycards are removed.

• Uses the same UTY-XWZXZD kit and connects to indoor unit terminal CNA02.

• Prevents energy waste in unoccupied hotel rooms.

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2. Comfort and Noise Reduction

Nighttime Low Noise Function (Optical Sensor)

• Automatically reduces outdoor unit noise at night based on ambient light detection.

• Two selectable levels:

  • Level 1: -3 dB reduction

  • Level 2: -5 dB reduction

• Configurable priority between Quiet Operation or Capacity Maintenance.

• Requires UTY-XWZXZ6 kit and connection to CN131 terminal on outdoor PCB.

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Ventilation Interlocked Operation Function

• Links ventilator fans with the air conditioning fan operation to maintain comfort and air quality.

• Especially useful in conference or lobby areas where airflow consistency is critical.

• Uses UTY-XWZXZC kit connected to CNB01 terminal on indoor unit PCB.

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3. Monitoring and Control Functions

Operation Status Monitoring

• Provides a visual indication of indoor unit operation and fault conditions via LED indicators or external lamps.

• Enables centralized supervision of multiple indoor units in hotels or hospitals.

• Uses UTY-XWZXZC connected to CNB01 terminal.

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Batch Stop Function (Local)

• Allows manual or automatic shutdown of all indoor units within the same refrigerant circuit.

• Activated via external switch connected through UTY-XWZXZD kit to CNA02.

• Commonly used for offices where power-off control is needed after hours.

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Emergency Automatic Batch Stop (Central Control)

• Integrates with fire alarm systems or building emergency stop circuits through central remote controller.

• When triggered, all connected VRF systems shut down automatically for safety.

• Implemented via UTY-XWZXZ7 kit connected to CN6 terminal on the controller PCB.

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4. Cold Climate Function

Antifreeze Function

• Activates a base heater when the outdoor temperature drops below 2°C to prevent freezing at the drain outlet.

• Uses UTY-XWZXZ9 kit connected to CN115 terminal on the outdoor PCB.

• Essential for maintaining reliability in cold climates.

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5. Summary of External Input/Output Specifications

Conclusion

The Fujitsu AIRSTAGE VRF External I/O System expands system control versatility with multiple energy-saving and safety functions.
By using optional external connection kits, installers can easily integrate smart building features such as:

• Automatic energy optimization

• Occupancy-based operation

• Remote monitoring and emergency shutdown

These I/O-based solutions enhance system efficiency, occupant comfort, and operational safety across various commercial environments.