Burner Calibration; Firing Output; Maximum Burner Output; Minimum Burner Output - Riello RS 190/M Installation, Use And Maintenance Instructions

5.8

Burner calibration

The optimum calibration of the burner requires an analysis of the
flue gases at the boiler outlet.
Adjust successively:
 Firing output
 Maximum burner output
 Minimum burner output
 Intermediate outputs between low and high fire
 Air pressure switch
 Minimum gas pressure switch
 Maximum gas pressure switch
5.8.1

Firing output

Pilot adjustment has been illustrated on page 17.
5.8.2

Maximum burner output

Maximum output of the burner must be set within the "Firing rates"
range shown at page 9. In the above instructions we left the burner
running in MIN. output operation.
 Move the selector 1)(Fig. 38, page 28) in manual position.
 Move the selector 2)(Fig. 38, page 28) in position (+) (increase
output) and keep it until the servomotor has opened the air
damper and the gas butterfly valve to 90°.
Gas Calibration
Measure the gas delivery at the meter.
A guideline indication can be calculated from the Fig. 18, page 20,
simply read off the gas pressure on the manometer (Fig. 34,
page 26), and follow the instructions at page 20.
 If delivery needs to be reduced, reduce outlet gas pressure
and, if it is already very low, slightly close adjustment valve.
 If delivery needs to be increased, increase outlet gas pressure.
Adjusting air delivery
Progressively adjust the end profile of cam 4)(Fig. 43) by turning
the cam adjustment screws as they appear through the access
opening 6).
 Turn the screws clockwise to increase air delivery.
 Turn the screws counter-clockwise to reduce air delivery.
Start-up, calibration and operation of the burner
31
5.8.3

Minimum burner output

Minimum output must be selected within the "Firing rates" range
shown at page 9.
 Move the selector 1)(Fig. 38, page 28) in manual position.
 Move the selector 2)(Fig. 38, page 28) in position (-) (reduc-
tion output) until the servomotor has closed the air damper
and the gas butterfly valve to 15° (factory set adjustment).
Adjusting gas delivery
Measure the delivery of gas from the gas meter.
 If this value is to be reduced, decrease the angle of black cam
slightly by proceeding a little at a time until the angle is
changed from 15° to 13° or 11°....
 Move the selector 1)(Fig. 38, page 28) in manual position.
 If it has to be increased move the selector 2)(Fig. 38, page 28)
in position (+) (increase output) (i.e. open the gas butterfly
valve by 10-15°), increase the cam black angle with small suc-
cessive movements, i.e. take it from angle 15° to 17° - 19°....
(Refer to paragraph "Cams adjustment" on page 28).
 Move the selector 2)(Fig. 38, page 28) in position (-) (reduc-
tion output) until the servomotor is taken to the minimum
opening position and measure the gas delivery.
The servomotor follows the adjustment of cam only
when the cam angle is reduced.
If it is necessary to increase the cam angle, first in-
WARNING
crease the servomotor angle with the switch "output
increase", then increase the black cam angle, and
at the end bring the servomotor back to the MIN out-
put position with the switch "output decrease".
Adjustment of air delivery
Progressively adjust the starting profile of cam 4)(Fig. 43) by turn-
ing the screws working through the access hole 6).
1
Key
1 Servomotor
2 Graduated sector for gas butterfly valve
3 Index for graduated sector 2
4 Adjustable profile cam
5 Adjustment screws for cam starting profile
6 Adjustment fixing screws
7 Adjustment screws for cam and profile
8 Cam
GB
20162481
3
2
5
8
4
7
6
Fig. 43
20160742