Unigas HR91A, Инструкция по установке, использованию и обслуживанию

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PART III: OPERATION
35
6.0
ADJUSTMENTS FOR GAS OPERATION
6.1 Adjustments - brief description
z
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.
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
differential pressure gauge, as described on par. “Measuring the gas pressure in the combustion head”.
z
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.
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 model provided.
6.2
1
Air and Gas Flow Rate Settings by means of Berger STM30../Siemens SQM40.. actuator
check the fan motor rota-
tion.
2 Only for burners provided with Multibloc MB-DLE gas valves: before starting the burner up, set the slow opening. To set the slow
opening, remove cover T , reverse it upside down and use it as a tool to rotate screw VR . Clockwise rotation reduces start flow rate,
anticlockwise rotation increases it. Do not use a screwdriver on the screw VR !
Note: the screw VSB must be removed only in case of replacemente of the coil.
3 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.
4 Start the burner up by means of the thermostat series and wait until the pre-purge time comes to an end and that the burner starts
up;
5 drive the burner to high flame stage, by means fo the thermostat TAB .
6 Then move progressively the microswitch to higher values until it reaches the high flame position; always check the combustion
values and eventually adjusting the gas by means of the valves group stabiliser.
7 go on adjusting air and gas flow rates: check, continuosly, the flue gas analisys, as to avoid combustion with little air; dose the air
according to the gas flow rate change following the steps quoted below;
8 acting on the pressure stabiliser of the valves group, adjust the gas flow rate in the high flame stage as to meet the values
requested by the boiler/utilisation:
- Siemens VGD valves group: remove cap T and act on the VR adjusting screw to increase or decrease the pressure and conse-
quently the gas rate; screwind VR the rate increases, unscrewing it decreases (see next figure).
Siemens SQM40
Actuator cams (SQM40)
I High flame
II Stand-by
III Low flame - gas
IV Low flame - oil
V Ignition - oil
VI Ignition - gas
MAN-AUTO
mensions
Dimensions in
SQM4...
I
III
II
IV
V
VI VI
V
IV
II
III
I