38
Installation instructions
MODULATION OF COMBUSTION OUTPUT:
The circuit board simultaneously performs two combustion output modulations:
1 Modulation of flue gas temperature.
2 Modulation of boiler temperature.
The modulation of the flue gas temperature limits the temperature of the flue gas leaving the flue.
The limitation is defined by parameter n° 15 (Maximum Flue Gas Temperature) which is the maximum limit allowed for outlet flue gas.
The board acts on the fan speed by decreasing the speed 15°C before parameter n° 15 in three 5°C steps.
For example, if the maximum allowed temperature is 180°C, when the flue gas temperature rises, the fan is stopped by a fixed
value of 5 points for each step.
If the flue gas temperature reaches the maximum, the fan is stopped by 50 points.
Modulation of the boiler temperature is performed on an 8°C scale in four 2°C steps, starting from the boiler working temperature
defined by parameter n° 0 (see the list of electro-hydraulic diagram parameters page 23).
Furthermore, it is possible to adjust a higher or lower modulation according to the parameter n° 13 (Modulation Step) which allows
to adjust the fan stopping points as the temperature rises.
For example, if the parameter n° 0 (Boiler working temperature) is set at 80°C and the parameter n° 13 (Modulation Step) is set at
2 points, the fan speed will be decreased by a total of 8 points.
The two modulations can overlap if both are required generating the sum of the stopping points of both modulations.
Massima Temp. Fumi 180°C
Velocità nominale
-5 Punti
-10 Punti
-15 Punti
-50 Punti
-5°C
-10°C
-15°C
Temp. Lavoro Caldaia 80°C
Velocità nominale
-2 Punti
-4 Punti
-6 Punti
-8 Punti
76°C
78°C
74°C
72°C
fig. 32
fig. 33
Maximum flue gas temperature 180°C
Nominal speed
Points
Points
Points
Points
Nominal speed
Points
Points
Points
Points
Boiler working temperature 80°C
