Access 5.4

Refrigerant leak detection


Leak Detection Requirements for Flammable Refrigerants

For systems using refrigerant type R454B, two refrigerant leak detection sensors are required:

  • One sensor in the supply air section
  • One sensor in the extract air section

For systems using refrigerant type R290, four refrigerant leak detection sensors are required:

  • Two sensors in the supply air section
  • Two sensors in the extract air section

The sensors communicate via Modbus for address configuration and data exchange. [Setup instructions]


Leak Detection-Related Alarms

The leak detection function is associated with the following alarms:

  • AL 3170 – Gas Detection Alarm: Indicates that a refrigerant leak has been detected and the gas evacuation mode has been activated.
  • AL 4040 – Heat Pump: Incorrect Refrigerant Type Selected
    Triggered during commissioning if the selected refrigerant type does not match the system configuration. This alarm prevents system startup until the correct refrigerant type is configured.
  • AL 4045 – Service Reminder: Heat Pump Refrigerant System
    A soft reminder to plan periodic leak detection testing and preventive maintenance. This is essential for ensuring safe and reliable operation.
  • AL 4050 – Service Overdue: Heat Pump Blocked
    If testing and maintenance are not performed within 30 days of AL 4045 activation, this alarm is triggered. The heat pump is then blocked from operation until all required service procedures are completed successfully.