We reserve the right to make changes without prior notice
50
6.7 Secondary functions
Below is a description of the controller secondary functions.
6.7.1 Dirty filters alarm
If the unit is supplied with a filter differential pressure switch, the “dirty filters” alarm, which warns about
excessive air filter fouling, is enabled when the digital input connected to the filter differential pressure switch
is opened.
This is not a serious alarm: it is merely a warning message which does not cause any devices in the unit to
stop.
6.7.2 Washing function
When a unit equipped with dampers is started, the air change (washing) can be overridden for a preset time
whose value is stored in the controller. When this function is enabled, the controller fully opens the ejection
and external air dampers and closes the recirculation damper.
When this function is active, it is possible to enable/disable temperature control.
When washing is active, the main screen shows a flashing button reading “Enter
Suspend”, which is
designed to suspend the procedure by a click on the Enter button before the washing time has elapsed.
Opening of the external air damper can be limited by the condensing pressure in summer mode and the
evaporation pressure in winter mode, as explained above.
6.7.3 Limitation of air delivery temperature
Temperature control always refers to the ambient temperature. However, to avoid situations of temperature
discomfort in the room, the software controls a min. and max. air temperature value in the delivery line.
In summer mode the controller manages the min. value of the air temperature in the delivery line. If this
temperature drops within the corresponding differential, the controller starts switching off the compressors
progressively, where they are active, and closes the external air damper gradually, where it is fitted and open,
until the min. value is reached, after which all the compressors are switched off and the external air damper, if
fitted, is closed completely.
Similarly, in winter mode the controller manages the max. value of the air temperature in the delivery line. If
this temperature rises within the corresponding differential, the controller starts switching off the compressors
progressively, where they are active, and closes the external air damper gradually, where it is fitted and open,
until the max. value is reached, after which all the compressors are switched off, the external air damper, if
fitted, is completely closed, the electric heaters are switched off, and the hot water valve is completely closed.