If just one outdoor sensor should be connected, connect it to AF1. This outdoor temperature is
then used also for HK2 and HK3.
5.2.1 Gradient characteristic
Basically, the following rule applies: a decrease in the outdoor temperature causes the flow tem-
perature to increase. By varying the
Gradient and Level parameters, you can adapt the charac-
teristic to your individual requirements. Increasing
Gradient results in a higher flow tempera-
ture, decreasing
Gradient in a lower flow temperature. The parameter Level performs a parallel
transport of the heating characteristic in an upward or downward direction.
Outside the times-of-use, reduced set points are used for control:
Reduced flow set point =
Flow set point – Set-back difference.
The
Max. flow temperature and Min. flow temperature parameters mark the upper and lower lim-
its of the flow temperature. A separate gradient characteristic can be selected for the limitation
of the return flow temperature.
Examples for adjusting the characteristic:
4
Old building, radiator design 90/70:
Gradient approx. 1.8
4
New building, radiator design 70/55:
Gradient approx. 1.4
4
New building, radiator design 55/45:
Gradient approx. 1.0
4
Underfloor heating depending on arrangement: Gradient smaller 0.5
Functions
WE
Configuration
4-point characteristic
OFF
Co1, 2, 3 -> Fb10 = OFF
4-point characteristic
OFF
Co5 -> Fb03 = OFF (Anl 3, 5, 8 and 10)
Parameters
WE
Parameter level / Range of values
Gradient, flow
1.8
PA1, 2, 3 / 0.4 to 3.2
Level, flow
0 °C
PA1, 2, 3 / –30 to 30 °C
Set-back difference
20 °C
PA1, 2, 3 / 0 to 50 °C
Min. flow temperature
90 °C
PA1, 2, 3 / 20 to 130 °C
Max. flow temperature
20 °C
PA1, 2, 3 / 20 to 130 °C
5.2.2 4-point characteristic
The 4-point characteristic allows you to define your own heating characteristic.
It is defined by 4 points for the
Outdoor temperature, the Flow temperature and the Return flow
temperature. The Set-back difference at points 2 and 3 indicates how much the flow temperature
is reduced outside the times-of-use.
40
EB 5179 EN
Functions of the heating circuit
