Siemens RDG20 KN Series Basic Documentation page 109

Fan control with
modulating
heating/cooling control
(PWM, 3-pos or
DC 0...10 V)
Note
A6V11545892_en--_e
For 3-speed fan control:
The individual switching points for each fan stage can be adjusted via
P353...P355. The fan speed switch off point is 20% below the switch on point. The
diagrams below show fan speed control for modulating PI control.
For DC 0...10 V fan control:
If DC 0...10 V fan control is selected, the fan switching points are set using the
following parameters:
● P359 & P360: DC 0...10 V fan max. output
● P358: DC 0...10 V middle speed output
● P357: DC 0...10 V fan min. output
●
P356: Switching point for fan
Heating/cooling
1- or 3-speed
fan
DC 0...10 V fan
w Room temperature setpoint
Q Fan speed
YH Control demand "Heating"
YC Control demand "Cooling"
XpH Proportional band "Heating"
(P050)
XpC Proportional band "Cooling"
(P052)
The diagram only shows the proportional part of PI control.
Functions
Fan control
X Dead zone (P055)
dz
Fan speed switching point
high (P355)
Fan speed switching point
med (P354)
Fan speed switching point low
(P353)
Fan_max Max. DC 0...10 V fan speed
(P359 for heating & P360 for
cooling)
Fan_med Med. DC 0...10 V fan
speed
(P358)
Fan_min Min. DC 0...10 V fan speed
(P357)
Fan_on Fan switch-on point (P356)
4
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