Fan startup behavior
Return air sensor
Fan speeds are changed over automatically
(by the room controller). Manual fan speed presetting is possible only
in operating state Comfort.
No automatic fan control. For example, the fan is operated manually
on the fan coil itself and can be enabled via relay Q14 (relay Q14 is
ON in Comfort mode).
The motors of some fans do not have a sufficiently powerful torque to set the fan in
motion at the lowest speed. Multi-speed fans are, therefore, always started at the
highest speed and then switched back to fan speed 1.
• This feature also applies to manual fan-speed control via the room unit.
• The unused relay outputs are freely available for other purposes (see page 136)
Minimum on time
Each fan speed remains on for a pre-defined minimum period before switching to the
next higher speed. This enables the controller to adjust to the fan speed
Fan overrun time (switch-off delay)
When switching off an electric reheater (FNC03, FNC05), it is essential to ensure that
the residual heat from the electric heater battery is dissipated.
For this reason, the fan is switched off only after a delay. The overrun time can be
Periodic fan kick
If the room temperature is measured with a return air sensor in the fan coil (connected
to input B1 at the room controller, see Section 7), the fan must be switched on to
ensure that the effective room temperature is measured correctly.
The function "Periodic fan kick" is used for this purpose.
From version V2.36, a reduced functionality (without time values for Comfort and
Economy ) is available even if no return air sensor is parameterized.
Note! For tool architecture reasons, those time values are visible and settable in ACS
and in the HandyTool although not supported by the controller.
RXB (KNX) application library
FNC Description of functions for FC-10, FC-11, FC-12
28 Feb 2009