K N X
The fan runs at fan speed 1 for as long as the heating/cooling valve remains partly
open, or in the case of an electric heater, while the heater is in operation.
• It is enabled as soon as the controller specifies a valve position or an electric
heating output greater than 0.
• It is disabled when the controller specifies a valve position or electric heating output
equal to 0 and the minimum fan switch-on time has elapsed.
When the valve is fully open or the electric heater is operating at 100% (in the range
marked "a"), a sequence controller enables fan speeds 2 and 3 .
In addition to the control deviation, an integrator also comes into operation in the
range marked "a". This ensures that the fan switches to speed 2 (and later to speed 3)
if the control deviation has remained >0 for a period of time, even if the room
temperature has not reached the switching point for fan speed 2.
The fan does not switch back down to speed 2 and later to speed 1 until there has been
no control deviation for a period of time.
If the room operating mode changes ( Comfort, Economy etc.), the sequence
controller is reinitialized by the application. This produces the following response: If the
room temperature is within the dead band after the change of room operating mode,
the controller specifies valve positions of 0%, or in the case of electric heaters, these
are disabled, and the fan is switched off. However, any delay time (minimum switch-on
time, switch-off delay in conjunction with electric heating coil / reheater or periodic fan
kick ) is allowed to expire first.
The fan can also be operated via the KNX bus.
In S-mode, control is shared between two communication objects:
– Fan command value
– Enable fan command value (activates input Fan command value ).
When Enable fan command value is disabled, the controller controls the fan
automatically, and the Fan command value input is disabled.
Enable fan command value
R W K T U
0 1 1 0 0 1.003
Fan command value (Input communication object)
R W K T U
0 1 1 0 0 5.001
RXB (KNX) application library
1 ... 3-stufiger Ventilator
(Input communication object)
FNC Description of functions for FC-10, FC-11, FC-12
0 = Disabled / Off
1 = Enabled / On
255 = 100%
28 Feb 2009