Danfoss ECL 2000, User Manual

Page: 27 / 106

Weather Compensation Curves
EY.65.H4.02
21
7. WEATHER COMPENSATION CURVES
Weather compensation means that the ECL 2000 regulates the heat circuit tempera-
ture in accordance with the outdoor temperature.
Weather compensation is controlled by two user-definable curves:
•
A flow temperature curve
•
A return temperature curve.
Flow temperature curve
Outdoor temperature
The flow temperature curve shows the reference flow
temperature in the heat circuit as a function of the out-
door temperature. By modifying this curve, you deter-
mine what the flow temperature should be for various
values of the outdoor temperature.
At low outdoor temperatures, you will normally want a
higher flow temperature, as shown in the curve to the
left.
You can set up maximum and minimum values for the
reference flow temperature. This is explained on
page 22.
Return temperature
curve
Outdoor temperature
The return temperature curve controls return tempera-
ture limiting in accordance with the outdoor tempera-
ture. The curve shows the acceptable return temperature
as a function of the outdoor temperature.
Normally, a low outdoor temperature means that a
higher return temperature will be allowed. This is also
the case with the curve shown to the left.
For further information on return temperature limiting,
see page 47 and 48 (heat circuit) and page 58 and 59
(hot-water circuit).
The following pages provide instructions for setting up the curves.
Note:
The setting of the flow and return temperature curve is essential for the functioning of
the ECL 2000. Therefore, it is important to check that the resulting curve is reason-
able in relation to the controlled system.
Reference flow
temperature
Return tem-
perature limit