134
Heating curve of the heating water buffer cylinder
Heating curve
Change with
(
Buffer
Slope
0.5
100 °C
20
10
0
-10
-20
-30
56 °C
65 °C
71 °C
76 °C
B
A
E
D
C
Fig. 77
A
Lower limit "Minimum buffer temperature"
B
Upper limit "Maximum buffer temperature"
C
Heating curve (level and slope)
D
Limited heating curve (level and slope, minimum
and maximum limits)
E
Boiler modulating range
Set value determination (set buffer temperature)
The set temperature in the heating water buffer cylin-
der, "set buffer temperature", is calculated from the fol-
lowing factors:
■
Outside temperature
■
Heating curve
"Slope and level" (extended menu)
■
Minimum limit
"Minimum buffer temperature" (code 35)
■
Maximum limit
"Maximum buffer temperature" (code 34)
Characteristic curve
C
for the heating water buffer cyl-
inder is determined subject to the outside temperature
and the values selected for slope and level.
The determined curve
C
is limited by "Minimum buffer
temperature"
A
and "Maximum buffer temperature"
B
.
The value of "Limited heating curve"
D
is determined
subject to the outside temperature and is specified as
the "Set buffer temperature".
Actual value determination (actual buffer tempera-
ture)
The actual temperature in the heating water buffer cyl-
inder, "Actual buffer temperature", is determined from
the average value of the following buffer temperature
sensors: Buffer temperature sensor 1 (top) and the
sensor specified in "Buffer cylinder charging up to sen-
sor" (code 36), including the buffer temperature sen-
sors between them.
Time program
■
Heating water buffer cylinder charging times
You can set these charging times by adjusting the
time program for the heating water buffer cylinder.
■
Boiler operating mode
During the set time phases, the charging level of the
heating water buffer cylinder has an effect on the
boiler operation.
Operating modes (operating program)
The operating modes
"Automatic"
,
"Manual"
and
"Off"
are available for regulating the heating water
buffer cylinder.
The influence of the operating modes on the combus-
tion output of the boiler in turn influences the runtime
and the start-up frequency of the boiler.
The heating water buffer cylinder operating modes are
set in the "Extended menu" under "Buffer".
■
"Automatic"
In automatic mode, the automatically determined
"Set buffer temperature" is used.
■
"Manual"
In manual mode, a fixed set temperature can be
selected for the heating water buffer cylinder.
When manual mode is selected, the set value is
entered in the "Extended menu" under "Buffer".
■
"Off"
In "Off" mode the heating water buffer cylinder is
heated by the boiler.
The heating water buffer cylinder has no influence on
the boiler output control.
The boiler regulates to the set boiler water tempera-
ture ("Extended menu").
In "Off" mode, the boiler starts when the temperature
falls below the "Set system temperature", the highest
requested temperature of all control circuits.
Once the boiler reaches the "Boiler water tempera-
ture limit" (code 0E) for an adjustable time of "Boiler
water temperature delay" (code 0F), the boiler is
switched off.
Extended function
■
Reheating suppression with solar circuit
If a solar circuit is installed, reheating suppression of
the heating water buffer cylinder can be selected.
Reheating suppression changes the required set
value ("Set system temperature") of the heating
water buffer cylinder for solar heating (code 33).
The amended "Set system temperature" can ensure
that the heating water buffer cylinder is provided with
sufficient capacity for the solar circuit.
Function description
Control functions
(cont.)
5679249
Functions
