Heating Circuit Control Unit - Viessmann Vitoligno 300-C Installation And Service Instructions For Contractors

Control functions
(cont.)

Heating circuit control unit

Brief description
■ The set flow temperature of each heating circuit is
determined from the following parameters:
– Outside temperature
– Set room temperature
Operating mode
–
Heating curve slope and level
–
■ The flow temperature of the heating circuits is con-
trolled by the gradual opening or closing of the mix-
ers.
The mixer motor control changes the actuating and
pause times subject to the control differential (control
deviation).
Coding addresses that influence the heating circuit
■
control unit:
A0 to FB.
For a description, see codes overview.
Functions
The heating circuit flow temperature is captured by the
flow temperature sensor.
Example using the settings in the delivered condition
90
80
70
60
50
40
30
Fig. 61
Heating curve for operation with standard room
A
temperature
Heating curve for operation with reduced room
B
temperature
10 5 0 -5 -10
Outside temperature in °C
Time program
The control unit time switch regulates in accordance
with the times programmed in the "Heating" program
between central heating with standard room tempera-
ture and central heating with reduced room tempera-
ture.
Every operating mode has its own set level.
Outside temperature
A heating curve must be set to adjust the control unit
to the building and the heating system. See chapter
"Adjusting heating curves".
The heating curve characteristics determine the set
flow temperature subject to outside temperature. The
control unit regulates in line with an average outside
temperature. This is made up of the actual and the
adjusted outside temperature.
A
B
-20
-15
Function description
111