Siemens AVS75.39 Series User Manual page 143

Flow temperature
setpoint compensation
Flow temperature
setpoint compensation
Flow setp compensation
delay
Flow setpoint
compensation Xp / Tn /
Tv
Mixing valve Xp
Mixing valve Tn
Speed derivative action
time Tv
Siemens
Building Technologies
Line no. Operating line
5142 Flow setp compensation delay
5143 Flow setp compensation Xp
5144 Flow setp compensation Tn
5145 Flow setp compensation Tv
Setpoint compensation adapts the heat request to allow the intermediate circuit
temperature at B36 to achieve its setpoint (storage tank setpoint plus intermediate
circuit increase).
If the intermediate circuit temperature is too low, the request to the generator is
increased.
The maximum increase of the setpoint is limited to half the setpoint boost
(line 5020).
If the intermediate circuit temperature is too high, the request to the generator is
reduced. The source request can be minimally reduced to the storage tank
setpoint.
The parameter flow setpoint delay (line 5142) can be used to switch on or off
setpoint compensation. (Off or a value between 0 – 60 seconds)
After switching on the intermediate circuit pump, short-time temperature
fluctuations in the intermediate and primary circuit can occur.
These are ignored, due to the delay of setpoint compensation.
Setpoint compensation is released when intermediate circuit pump Q33 is switched
on at a minimum for the period entered here.
Operation of pump Q33 is started with the setpoint plus charging boost.
The PID controller can be influenced by parameters Xp, Tn and Tv. The controller
has a dead band of +/- 1 K.
By setting the right proportional band Xp for the mixing valves actuator, the control
behavior of the actuator is matched to those of the plant (controlled system).
The proportional band Xp influences the controller's P-action.
The P band Xp is the range by which the input variable x (controlled variable) must
change to adjust the output variable y (manipulated variable) throughout the entire
positioning range. The smaller the value the greater the jump. The illustration
depicts the reciprocal value 1/Xp = Kp.
By setting the right integral action time Tn, the control action of the mixing valve's
actuator is matched to the behavior of the plant (controlled system).
Tn influences the controller's I-response.
It is the required of the I-portion to undertake the same manipulated variable
change at the given input signal (controlled variable), as immediately provided by
the P-portion. The smaller the Tn the larger/faster the slope.
By setting the right derivative action time, the control action of the mixing valve's
actuator is matched to the behavior of the plant (controlled system).
Tv influences the controller's D-behavior. With Tv = 0, the D-action is deactivated.
User manual RVS43.345
The settings in detail
143 / 239
CE1U2354en_021
2013-09-02