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ENGLISH
The atomised fuel which exits the nozzle mixes with the fan-fed air and is ignited by the already-lit gas pilot flame.
After the magnet is switched on the pilot flame is switched off and the burner is run at the modulation minimum.
Flow increase occurs automatically and continuously according to the signals from the modulation probe: increase
is effected by means of a servomotor.
The modulation motor controls a simultaneous increase in the flow of both fuel and combustion air.
The increase in the flow of fuel is determined by the variable-profile disk which, by rotating, causes greater compres-
sion of the return pressure regulator spring and thus an increase in return pressure corresponds to an increase in
fuel flow.
An increase in fuel flow must correspond to an increase (of adequate quantity) of combustion air. This condition is
brought about during the first adjustment by acting on the screws that vary the combustion air adjuster control disk
profile.
Fuel flow and, at the same time, combustion air flow, increase up to maximum pressure (fuel pressure at return
pressure regulator of about 18 - 20 bar) if pressure at the pump is 20 - 22 bar.
Fuel and combustion air flow rates remain at maximum until boiler temperature (pressure in the case of a steam
boiler) nears the set value and causes the modulation control motor to invert rotation.
The return movement of the modulation motor causes a reduction in the flow of fuel and relative combustion air.
The modulation system reaches a position of equilibrium which corresponds to a flow of fuel and relative combustion
air equal to the quantity of heat requested by the boiler.
With the burner working the in-boiler probe detects variations in boiler load and automatically sends a signal to the
modulation motor to adjust the flow of fuel and relative combustion air accordingly.
If, even with just the minimum flow of fuel and combustion air, the maximum temperature (or pressure in the case of
a steam boiler) is reached, the thermostat (pressure switch in the case of a steam boiler) will shut down the burner
completely.
Subsequently, the temperature (or pressure in the case of a steam boiler) will drop back below the shutdown setting
and the burner will re-ignite as described above.
Bear in mind that the possible flow range, with good combustion, is approximately from 1 to 1/3 of the max flow rate
indicated on the ID plate.
Should the flame fail to appear within two seconds of the pilot flame igniting, the control box places the unit in “lock-
out” (complete shutdown of burner with relative warning light).
To “reset” the control box press the appropriate reset button.
Note:
The air pressure switch must be adjusted on igniting the burner as a function of the pressure value observed
for operation with the pilot flame.
Summary of Contents for GI 1000 DSPN-D
Page 23: ...23 ITALIANO SCHEMA DI PRINCIPIO REGOLAZIONE ARIA PER MODELLO GI 1000 DSPN D N 0002933410...
Page 24: ...24 ITALIANO SCHEMA DI PRINCIPIO REGOLAZIONE PILOTA GAS PER MODELLO GI 1000 DSPN D N 0002933930...
Page 50: ...50 ENGLISH BURNER GI 1000 DSPN D AIR FEEDING ADJUSTMENT PRINCIPLA DIAGRAM N 0002933410...
Page 51: ...51 ENGLISH N 0002933930 BURNER GI 1000 DSPN D GAS PILOT ADJUSTMENT PRINCIPLE DIAGRAM...
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