CIB UNIGAS - M039168CC
24
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 adjusting cam respec-
tively.
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Check that the combustion parameters are in the suggested limits.
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Check the flow rate measuring it on the counter or, if it was not possible, verifying the combustion head pressure by means of a dif-
ferential pressure gauge, as described on par. “Measuring the gas pressure in the combustion head” on page 21.
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Then, adjust the combustion values corresponding to the points between maximum and minimum: 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 throttle gas valve.
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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.
Now, adjust the burner according to the actuator model provided.
Adjustment procedure
To change the burner setting during the testing in the plant, follow the next procedure.
On the DUNGS MBC..SE gas valves group, set the pressure regulator to 1/3 of its stroke, using a 2.5 allen key.
1
Before starting the burner up, drive the high flame actuator microswitch matching the low flame one (in order to let the burner ope-
rates at the lowest output) to safely achieve the high flame stage.
2
cam IV (stroke limitation cam) must be set a little higher than the cam III to limit the output in the first seconds the flame appears;
NOTE:
cam IV must shift according to cam III.
ATTENTION:
before starting the burner up, be sure that the manual cutoff valves are open and check that the pres-
sure upstream the gas train complies the value quoted on paragraph “Technical specifications”. Be sure that the
mains switch is closed.
ATTENTION:
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 gas decrease slowly until the normal combustion values are achieved.
WARNING: EVER LOOSE THE SEALED SCREWS, OTHERWISE THE DEVICE WARRANTY WILL BE IMMEDIATELY
INVALIDATE!
IMPORTANT! the combustion air excess must be adjusted according to the in the following chart:
Recommended combustion parameters
Fuel
Recommended (%) CO
2
Recommended (%) O
2
Natural gas
9 ÷ 10
3 ÷ 4.8
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Pressure setting
