Air/Fuel Adjustment - Riello DB 20 SM HS C03 TC A0 FS1 FB T150 Installation, Use And Maintenance Instructions

7.8

Air/fuel adjustment

When setting the air/fuel ratio for the gas burners, the air and gas
variable profile cams must be used, Fig. 24.
Procedures for setting the burner
• Turn the AUTO / MAN selection switch on the control panel
to MAN (manual).
• Turn the burner on.
If it does not ignite, it could mean that the gas does not reach the
combustion head within the safety time period of 3 s. In this case
increase the ignition gas delivery level. When the burner ignites,
it can be completely set and adjusted.
Maximum output
Maximum output should be selected from the firing rates, see
Fig. 1.
Max. gas adjustment
Slowly increase the output, checking it does not exceed the max-
imum gas delivery, taking the servomotor to 130° and make the
first maximum setting to the air cam.
At this point, adjust the pressure regulator to reach the maximum
delivery required with the gas butterfly valves completely open
(90°), or turn the screws (2) Fig. 24 on the gas cam profile and/or
the gas train adjustment valve.
Max. air adjustment
Vary the final profile of the air cam by turning the screws (2)
Fig. 24. Do not turn just one screw, but turn those nearby as well,
so that the cam curve is progressive.
Minimum output
Min. gas adjustment
Using the manual switch, go to the minimum run (factory setting
20°). Change the gas cam profile by turning the screws (2).
Min. air adjustment
Change the initial air cam profile by turning the screws (2) on the
variable profile air cam.
Take care not to change the final parts of the profile of the cam
that regulates the air damper at maximum delivery, as previously
set.
Start-up, calibration and operation of the burner
1 2
3
D1499
4
1 Cam
2 Adjustment screws
3 Fixing screws
4 Variable profile
Intermediate output levels
Turn the manual switch to the intermediate levels.
The air/gas ratio is adjusted by turning the respective screws to
vary the air and gas cam profiles.
Take care not to change the final parts of the air and gas cam pro-
files, as previously set.
When adjustment is complete, block the transversal screws on
the variable profile cam.
23 GB
The gas is adjusted by varying the
relative cam profile.
Fig. 24
20111775