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Vitoflex 300-UF Installation & Operating
Parameter
Secondary Air
“General” tab
The secondary air parameters are used to determine
the heating output.
The amount of secondary air regulates the oxygen
content in the flue gas. Secondary air is blown in
through the side openings in the combustion chamber
walls. If the set value for the amount of secondary air
is exceeded, the amount of fuel supplied is reduced.
Parameter
Description
Setting
range
Standard
value:
“Secondary fan, full load”
Utilisation level of the secondary air fan at full load
Actual: Current utilisation level of the secondary air fan
Setting in %
25 to 90
60
“Secondary air fan, partial load” Utilisation level of the secondary air fan at partial load
Setting in %
10 to 50
40
“Current set value”
Displays the current set value for the secondary air fan
Sliding value between the set value for the secondary air fan at full load and
the set value at partial load
“Residual O
2
”
Set value for the residual oxygen content, control
variable for secondary air control
Setting in %
4 to 18
7
“Residual O
2
, partial load, offset” Sliding increase in the residual oxygen content at partial
load
Full load: 0 % increase, minimum partial load:
Up to 4% increase
Setting in %
0 to 4
0
“Current set value”
Displays the current set value for the residual oxygen content
Minimum value: residual O
2
setting (at full load)
Maximum value: residual O
2
setting and partial load offset
(at partial load: maximum 4%)
“Minimum output”
Minimum heating output of the heating system in
automatic mode
Setting is a % of the system’s inherent maximum
heating output
30 to 99
30
“Maximum output”
Maximum heating output of the heating system in
automatic mode
Setting is a % of the system’s inherent maximum
heating output
30 to 100
100