Fan Coil; Control Parameters With Pwm And Continuous Controller (Fan Coil) - ABB i-bus KNX Product Manual

4.3.4

Fan Coil

4.3.5 Control parameters with
PWM and continuous
controller (fan coil)
© 2009 Busch-Jaeger Elektro GmbH – A Company of the ABB Group
If fan coil is selected under "control types", the control values are output
in the same way as described at continuous controllers.
A fan coil also has the option of controlling fan stages using a 1-byte or
three 1-bit communication objects with a fan coil actuator.
Switching fan stages will heat or cool a room faster.
The fan stage that is to be enabled at which control value is defined on
a separate tab, "fan coil heating" or "fan coil cooling". Note that the threshold
values must not overlap, i.e. the stage 1 threshold value must always be less
that the stage 2 threshold value, which in turn must be less than the stage 3
threshold value.
With continuous control behaviour and switching PWM controllers the preset
control parameters can be used via the installation type of the heating or air-
conditioning system. If different parameters are required, they are set by free
parameterisation. Free parameterisation should only be used if the user has
sufficient experience in control technology.
The setting "free parameterisation" can be used to set the "proportional
range (Xp)" and the "readjust time (Tn)". The proportional range is above
and below the specified setpoint and determines the speed of the control.
The readjust time is three times the delay time (the delay time is determined
by the inflectional tangent of the heating curve of the room. With both
settings the slower the overall system the greater the values required.
Xp=Proportionalbereich
Stellgröße
Xp = 8 K
Xp = 6 K
Xp = 4 K
100%
0%
15°C
Xp=2 K
T
21°C
25°C
91