Riello DB3 SM C03 Installation, Use And Maintenance Instructions page 46

5
Preparation for start up
5.1 Combustion head setting
The servomotor 3)(Fig. 3) varies the air flow depending on
the output requested and manually also the setting of the
combustion head. This system allows an optimal setting
even at a minimum firing rate.
For the same servomotor rotation, combustion head open-
ing can be varied by moving the lever onto holes 1-2-3-4-5-
6, (Fig. 20), after loosening the screw 1).
The choice of the hole (1-2-3-4-5-6) to be used is decided
on the basis of diagram (Fig. 22) against the required maxi-
mum output.
Setting is pre-arranged in the plant for the maximum run
(hole 3). When dealing with boilers featuring a strong back
pressure, if air delivery is insufficient even with the damper
fully open, you can use a different setting to that illustrated
in diagram (Fig. 22) - do this by moving the tie rod onto the
next highest hole numerically speaking, thus increasing the
combustion head's opening and hence air delivery.
For operation on flame-reversal boilers, gas pipes must
be adjusted to hole position 4, see Fig. 21.
16
D3107
D9136
1
0
2
Fig. 20
Fig. 21
D3109
DB3 DB4-6
Fig. 22