System settings (Service menu – Settings)
Logamatic EMS – 6 720 801 387 (2011/05)
36
6
6.4.3 Heating curve
Parameter: design temperature, maximum and minimum flow temperature and room temperature
offset (parallel shift).
The heating curve is the decisive basic factor for an economic and convenient operation of the
heating system with outside temperature compensated control. For the calculation of this curve the
Logamatic control system requires information about some of the heating system characteristics,
and from this it calculates automatically and by means of a mathematical formula the optimum
heating curve. As part of this it takes into account the adjusted outside temperature and the room
control temperature. The room control temperature is in turn an internal calculation factor, which is
comprised of the desired room temperature (room target temperature) and the room influence. By
means of this the user can immediately influence the heating curve by changing the room target
temperature. The heating curve (
Æ
display 7, page 37) is essentially defined by its base point and
end point. The base point is located at 20 °C flow temperature at a room temperature of 20 °C with
an adjusted outside temperature of 20 °C. The end point of the heating curve must be set according
to the design temperature of the heating system. The defining factors for the run of heating curve
(incline/steepness) are the two parameters
minimum outside temperature
(the lowest expected
outside temperature in a region, page 28) and the
design temperature
(the flow temperature
which should be reached at the minimum outside temperature),
Æ
display 7, left.
With the parameter for
minimum flow temperature
a minimum target value can be specified
(
Æ
display 7, [4], page 37). The burner starts again if the set value is no longer achieved.
The heating characteristic curve can be shifted up or down parallel to the original curve by adjusting
the
room temperature offset
parameter and/or the set room temperature (
Æ
fig. 7, right,
page 37). Setting the offset may be advisable should the room temperature measured by a
thermometer deviate from the selected set value.
The X axis of the heating curve depicted graphically in the display relates to the area of
+20 °C to – 20 °C.
Under
design
parameter the minimum outside temperature, which is set under system
data, is depicted by a circle. If a minimum outside temperature of under – 20 °C is
entered, the depiction is however no longer completely correct (the circle no longer lies
on the heating curve).
