The FCU_Antifrost component is used to protect against a drop in the space temperature below the set threshold (with the hysteresis).

If the value of the space temperature drops below the value equal to Threshold – Diff slots (6oC for values in the figure below), and there is no sensor fault, the Antifrost slot changes to true. This process is run until the room temperature increases above the value equal to Threshold + Diff slots (8oC for values in the figure below). If the temperature sensor is faulty (the Sensor Fault slot is true), the Antifrost slot is always set to false–the component is inactive.

The FCU_Antifrost component

The FCU_Antifrost component has the following slots:

  • Antifrost: the Boolean output slot (true: antifrost, false: OK (no antifrost);
  • Sensor Fault: the Boolean input slot, which provides the information about the fault of the temperature sensor;

Note: If the Sensor Fault slot is true, the Antifrost component is inactive (because the value read from the temperature sensor is incorrect), and the value of the Antifrost slot is set to false. If the Sensor Fault slot is false, the Antifrost component is active,

  • Temperature: the value from a temperature sensor for controlling the space;
  • Threshold: allows to set the threshold temperature value;
  • Diff: allows to set the differential for hysteresis.