User Manual

Functions
Control outputs
4
A6V11545892_en--_a 77 | 146
The demand calculated from the current room temperature and setpoint is provided
via Y1, Y2 and Y3 to the valve actuator as a PWM (pulse width modulation) signal
for thermal actuators. The control output is activated for a period proportional to the
heating/cooling demand and then switched off for the rest of the PWM interval.
The PWM algorithm cycle time is 1200 seconds (factory setting). It can be adjusted
via P206 (Y1), P207 (Y2) or P208 (Y3). These parameters are only displayed if
PWM is selected via DIP switches 7 and 8 and if PWM is selected via P201, P203,
P204.
● For a more accurate control temperature with PWM signals, the integral action
time (P057 and P058) must be set to 0 (Proportional control).
● For P-band (P050, P052, P054), see Control sequences [➙ 54].
For thermal valve actuators (STA, STP), set the PWM algorithm cycle (P206, P207,
P208) to 1200 seconds. Proposed setting range for optimization: 900 to 1800
seconds.
● It is impossible to ensure exact parallel running of 2 or more thermal valve
actuators. Motorized actuators with On/Off or 3 position control take
precedence if several fan coil systems are controlled by the same room
thermostat.
When electrical equipment needs to be controlled, it is requested to use a suitable
external switching element to switch the maximal current.
When the Y2 output controls external mechanical relays, the optimal running time
(P207) depends on the technical characteristic of the equipment.
As first setting, we suggest the following values, which could be modified in the
described setting range if needed:
● Electric heater applications: 300 s (5 min) / range 30...60 s
● Electric radiator applications: 1200 s (20 min) / range 120...1800 s (30 min)
● Electric floor heating: 1200 s (20 min) / range 30...1800 s (30 min)
When the Y2 output controls one external solid state relay:
● Electric heater applications: 60 s / range 15...60 s
● Electric radiator applications: 300 s (5 min) / range 30...300 s (5 min)
● Electric floor heating: 600 s (10 min) / range 30...900 s (15 min)
To avoid burn-off of mechanical contacts by frequent switching, use a current valve
in place of a relay or contactor.
To avoid possible supply problems, when many consumers are switching on at the
same time in a building, we suggest considering the following points:
● Set slightly different PMW cycles
● Do not switch all rooms to Comfort at the same time
This function is available with RDG260KN only.
The demand calculated by PI control from the current room temperature and
setpoint is provided via Y10 and Y20 to the valve actuator as a continuous
DC 0...10 V signal.
● Parameter P256 (RDG260KN) sets the heating flow limitation when PICV is
installed in heating and cooling systems at output Y10. See Additional functions
[➙ 41].
● For P-band (P050, P052, P054), see Control sequences [➙ 54].
PWM control
(RDG200KN only)
Note
PWM for valve actuators
(RDG200KN)
Note
PWM for electric heaters
(RDG200KN)
Note
DC 0...10 V control
DC 0...10 V
for valve actuators
Note