Unigas HR91A, Инструкция по установке, использованию и обслуживанию

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PART III: OPERATION
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4.3 Gas operation
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Check the gas feeding pressure is sufficient (signalling lamp G3 on).
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the gas proving system test begins; when the test is performed the proving system LED turns on. At the end of the test, the burner
staring cycle begins: in case of leakage in a valve, the gas proving system stops the burner and the lamp
B1 turns on.
NOTE: if the burner is fitted with Dungs VPS504, the pre-purgue phase starts once the gas proving system is successfully performed.
Since the pre-purgue phase must be carried out with the maximum air rate, the control box drives the actuator opening and when the
maximum opening position is achieved, the pre-purge time counting starts.
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At the end of the pre-purge time, the actuator drives the complete closing (ignition with gas position) and, as this is achieved the
ignition transformer is energised (LED
B4 is on); the gas valves open.
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Few seconds after the valves opening, the transformer is de-energised and lamp B4 turns off.
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The burner is now operating, meanwhile the actuator goes to the high flame position and, after some seconds, the two-stage ope-
ration begins; the burner is driven automatically to high flame or low flame, according to the plant requirements.
Operation in high or low flame is signalled by lamp B2 on the frontal panel.
4.4 Light oil operation
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The fan motor starts and the pre-purge phase as well. Since the pre-purge phase must be carried out at the maximum air rate, the
control box drives the actuator opening and when the maximum opening position is reached, the pre-purge time counting starts.
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At the end of the pre-purge time, the actuator is in the light oil ignition position: the ignition transformer is energised (lamp B4 on);
the ignitor gas valves and the light oil valves open. Few seconds after the valves opening, the transformer is de-energised and
lamp
B4 turns off.
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The burner is now operating, meanwhile the actuator goes to the high flame position; after some seconds, the two-stage operation
begins; the burner is driven automatically to high flame or low flame, according to the plant requirements.Operation in high or low
flame is signalled by LED
B2 on the burner control panel.
The fuel is pushed into the pump to the nozzle at the delivery pressure set by the pressure governor. The solenoid valve stops the fuel
immission into the combustion chamber. The fuel flow rate that is not burnt goes back to the tank through the return circuit. The spill-
back nozzle is feeded at constant pressure, while the return line pressure is adjusted by means of the pressure governor controlled by
an actuator coupled to an adjusting cam.