8
System-wide functions
8.1
Weather-compensated control
When weather-compensated control is used, the flow temperature is controlled according to the
outdoor temperature. The boiler characteristic in the controller defines the flow temperature set
point as a function of the outdoor temperature (–> Fig. 5). The outdoor temperature required for
weather-compensated control is measured at the outdoor sensor at the input AF or received
over a 0 to 10 V signal at the input AE2.
Caution!
Pt 100 or Pt 1000 sensor should be used for measuring the flow temperature as only these sensors
guarantee measurements up to 160 °C (max. temperature of the flow temperature set point).
Function
WE
Configuration
Outdoor sensor
ON
3 °C
Co5 -> Fb00 = ON
FUEHL: Outdoor temperature sensor AF
0–10: 0 to 10 V signal
Frost protection limit / –30 to 20 °C*
* See section 8.8
EB 5474 EN
49
System-wide functions
130
120
110
100
90
80
70
60
50
40
30
20
20
16
12
8
4
0
-4
-8
-12
-16
-20
2.4
3.2
2.9
2.6
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.4
0.2
[
˚
C]
[
˚
C]
t
VL
t
A
Fig. 5 · Gradient characteristic
t
VL
Flow temperature
t
A
Outdoor temperature
