Minimum Output; Intermediate Outputs - Riello 20074125 Installation, Use And Maintenance Instructions

6.6.4

Minimum output

Min output must be selected within the firing rate range shown on
Fig. 3 on page 12.
Press button 2)(Fig. 29 on page 30) "Diminishing output" and
keep it pressed until the servomotor regains (Fig. 32 B) the ad-
justment made in the factory: See Tab. K on page 29 and as a
consequence adjusting the air damper 5) and the gas butterfly
valve 4) (Fig. 31 on page 31).
Adjustment of gas delivery
Progressively adjust the end profile of the mechanical cam 1)
Fig. 31 on page 31, using the screws 2).
For example, calibrate the minimum output to 800 kW, check the
emissions and if necessary increase or decrease the opening of
the air damper (see "Air adjustment" on page 31.). Bring the out-
put to 800 kW using the screws 2) of the mechanical cam (Fig. 31
on page 31) and check the emissions.
Air adjustment
The regulation of the air is carried out using the angle of the cam
III) of the servomotor (Fig. 28 on page 29) and by using the se-
lector 2)(Fig. 29 on page 30). To adjust the cam of the servomo-
tor, see Fig. 32 A).
NOTE:
The servomotor follows the adjustment of cam III only when
the angle of the cam is reduced. If it is necessary to increase
the angle of the cam, you must first increase the angle of the
servomotor by means of the "output increase" key, then in-
crease the angle of cam III, and finally bring the servomotor
to the position of MIN output, with the "Output reduction"
key.
To adjust the cam III, see Fig. 32 A) e B).
20079034
Start-up, calibration and operation of the burner
6.6.5

Intermediate outputs

Air adjustment
No adjustment is required
Adjustment of gas delivery
After adjusting the maximum and minimum output of the burner,
carry out air adjustment on higher intermediate positions of the
servomotor. The passage from one position to the next one is ob-
tained by pressing the button 2) on the symbol (+) or (-) (Fig. 29
on page 30). For a brief period press the button 2)(Fig. 29 on
page 30) "Output increase" so that the servomotor rotates by
about 20°, see servomotor graduated index Fig. 32 B) and the air
damper graduated index 5) (Fig. 31 on page 31).
Screw or unscrew the screw 2) of the mechanical cam (Fig. 31 on
page 31) to increase or decrease the gas output so as to adjust
it to the corresponding air output, to obtain optimal combustion.
Proceed in the same way with the other screws.
Take care that the cam profile variation is progres-
sive.
WARNING
Switch off the burner using the switch 1)(Fig. 29), OFF position,
release the mechanical cam I)(Fig. 31) to separate the gears of
the servomotor, pressing and shifting downwards the button
3)(Fig. 32 D) and check a few times, by rotating the mechanical
cam I)(Fig. 31) manually backwards and forwards, that the move-
ment is smooth and without any hindrance.
It is recommended that the mechanical cam
I)(Fig. 31 on page 31) be bound again to the ser-
vomotor by shifting button 3)(Fig. 32 C) upwards.
WARNING
As far as is possible, try not to move those screws at the ends of
the mechanical cam that were previously adjusted for the open-
ing of the gas butterfly valve to MAX and MIN output.
NOTE:
Once you have finished adjusting the "MAX - MIN - INTER-
MEDIATE" outputs, check ignition once again: noise emis-
sion at this stage must be identical to the following stage of
operation. If you notice any sign of pulsations, reduce the ig-
nition stage delivery.
32 GB