PART III: OPERATION
29
Fig. 20 - Burner front panel
ADJUSTING AIR AND GAS FLOW RATES
Adjustments - brief description
Adjust the air and gas flow rates at the maximum output (“high flame”) first, by means of the air damper and the valves group
pressure stabiliser respectively.
Check that the combustion parameters are in the suggested limits.
Check the flow rate measuring it on the counter or, if it was not possible, verifying the combustion head pressure by means of a
differential pressure gauge, as described on par. “Measuring the gas pressure in the combustion head”.
Then, adjust the combustion values corresponding to the points between maximum and minimum (progressive -fully modulating
burners only): set the shape of the adjusting cam foil. The adjusting cam sets the air/gas ratio in those points, regulating the
opening-closing of the air damper.
Set, now, the low flame output, acting on the low flame microswitch of the actuator in order to avoid the low flame output increasing
too much or that the flues temperature gets too low to cause condensation in the chimney.
To change the burner setting during the testing in the plant, follows the next procedure, according to the model provided.
WARNING! During commissioning operations, do not let the burner operate with insufficient air flow (danger of
formation of carbon monoxide); if this should happen, make the fuel decrease slowly until the normal combustion
values are achieved.
WARNING! the combustion air excess must be adjusted according to the values in the following chart.
Recommended combustion parameters
Fuel
Recommended (%) CO
2
Recommended (%) O
2
Natural gas
9 ÷ 10
3 ÷ 4.8
LPG
11 ÷ 12
2.8 ÷ 4.3
S1
B1
S2
B2
B3
B4
B5
G1
G2
G3
S3
Keys
B1
Lock-out LED
B2
Hi-flame operation LED
B3
Lo-flame operation LED
B4
“Ignition transformer operation” LED
B5
“Fan motor overload tripped” LED
G1
“EV2 opening” LED
G2
“EV1 opening” LED
G3
“Gas pressure switch signal ” LED
G4
Gas proving system lockout signalling LED
S1
Main switch
S2
Reset pushbutton for control box
S3
Operation selector MAN - AUTO (operation in manual
or automatic mode):
MIN = operation with minimum output
MAX = operation at the maximum output
G4
