5 Use and operation
Buffer difference
The burner starts when the
tank temperature top
falls
below the
required flow temperature
minus the
buffer
difference
.
Example:
- Current required flow temperature = 50°C
- Buffer difference = 5°C
The burner starts as soon as the
tank temperature
top
< 45°C.
A negative buffer difference value is added, i.e. the
burner starts earlier.
Example:
- Current required flow temperature = 50°C
- Buffer difference = - 5°C
The burner starts as soon as the
tank temperature
top
< 55°C.
Outside temperature delay
The delay set here is used to determine an average
value for the outside temperature (= Average outside
temperature).
The heating circuit pump switches on if the average
temperature and the current outside temperature fall
below the ambient switch off temperature (within the
heating period), or below the reduced mode ambient
switch off temperature (outside the heating period).
The heating circuit pump switches off again as soon
as the current outside temperature rises above the
value of the ambient switch off temperature.
Heating circuit name
The heating circuit can be given an individual name.
6.1.3 Heating curve
The heating circuit flow temperature is controlled by
the heating circuit operating mode
and by the
outside temperature. The heating curve represents
the relationship between these two temperatures. In
other words, the boiler control uses the outside tem-
perature to calculate the temperature (=
calculated
required flow temperature
) with which the heating cir-
cuit is supplied.
In
heating mode
the heating curve for heating mode
4
(red) is used.
In
reduced mode
the heating curve for reduced mode
5
(= heating curve for heating mode minus
reduction
)
is used.
The heating curve must be adapted to suit each buil-
ding and its heating system.
2-point heating curve
Abb. 2-32
1 Maximum heating circuit flow temperature
[1]
2 Calculated required flow temperature
3 Reduction (the value by which the reduced
temperature is lower than the heating tem-
perature)
4 Heating curve for heating mode (shown in red)
5 Heating curve for reduced mode (blue)
6 Minimum heating circuit flow temperature
[1]
7 Flow temperature at outside temperature -
15°C
8 Flow temperature at outside temperature
+15°C
!
1)
ATTENTION
- This temperature is system-
specific and must be agreed with the heating
engineer. Only to be set by qualified per-
sonnel.
The desired heating circuit required flow temperature
in heating mode is set for an outside temperature of -
15°C
7
and +15°C
8
. Between these outside tem-
peratures, the required flow temperature is calculated
from the characteristics of the heating curve (inter-
polated).
26
Operation manual
maximus L
