Unigas HTP90A, Инструкция по установке, использованию и обслуживанию, Страница: 27 / 60

C.I.B. UNIGAS - M039219CA
27
Air and gas flow rate adjustements
During the factory test, the gas butterfly valve, air damper in low flame and actuator are set to average values.
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.
z
Check that the combustion parameters are in the suggested limits.
z
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 24.
z
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.
z
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 servocontrol model provided
(mod. Berger STM30.. or mod. Siemens SQL..).
Adjusting procedure
If the burner is provided with the DUNGS MBC..SE gas valves group, set the pressure regulator to 1/3 of its stroke, using a 2.5 allen
key.
Now, adjust the burner according to the actuator model provided.
The burner is factory-set wih the adjusting plate holes fully open, and the combustion head at its MAX position, so it is fit to work at the
maximum output.
To adjust the gas flow, partially close the holes, as follows:
1 loosen the three V screws that fix the adjusting plate D ;
2 insert a screwdriver on the adjusting plate notches and let it move CW/CCW as to open/close the holes;
3 once the adjustmet is performed, fasten the V screws.
CAUTION: perform these adjustments once the burner is turned off and cooled.
ATTENTION: before starting the burner up, be sure that the manual cutoff valves are open and check that the
pressure 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 (dan-
ger of formation of carbon monoxide); if this should happen, make the gas decrease slowly until the normal
combustion values are achieved.
WARNING: never 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
Light oil 11.5 ÷ 13 2.9 ÷ 4.9
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Pressure setting