PART III: OPERATION
26
Integrated proving system (burners equipped with LME7x, LMV, LDU)
AIR FLOW AND FUEL ADJUSTMENT
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.
Check that the combustion parameters are in the suggested limits.
.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.
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.
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.
ADJUSTMENTS FOR GAS OPERATION
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 valves group
pressure stabiliser respectively.
Check that the combustion parameters are in the suggested limits.
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”.
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.
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.
WARNING! 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 fuel decrease slowly until the normal combustion
values are achieved.
WARNING! the combustion air excess must be adjusted according to the values 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
LPG
11 ÷ 12
2,8 ÷ 4,3
PS
EV1
EV2
/
EV2
EV1
PGCP
This paragraph describes the integrated proving system operation sequence:
At the beginning both the valves (EV1 and EV2) must be closed.
Test space evacuating: EV2 valve (burner side) opens and keep this position for a preset time
(td4), in order the bring the test space to ambient pressure.Test atmospheric pressure: EV2 clo-
ses and keep this position for a preset time (test time td1). The pressure switch PGCP has not to
detect a rise of pressure.
Test space filling: EV1 opens and keep this position for a preset time (td3), in order to fill the test
space.
Test gas pressure: EV1 closes and keep this position for a preset time (td2). The pressure switch
PGCP has not to detect a pressure drop down.
If all of the test phases are passed the proving system test is successful, if not a burner lockout
happens.
On LMV5x and LMV2x/3x and LME73 (except LME73.831BC), the valve proving can be parameteri-
zed to take place on startup, shutdown, or both. On LME73.831BC the valve proving is parameteri-
zed to take place on startup only.
