PART III: OPERATION
29
ADJUSTMENTS FOR GAS OPERATION
Adjustment procedure
1 Turn the burner on by means of its main switch
S1
: if the burner locks (LED
B1
on in the control panel) press the RESET button
(
S2
) on the control panel. See chapter “Operation” for further details.
2 check the fan motor rotation
3 Start the burner up by means of the thermostat series and wait unitl the pre-purge phase comes to end and that burner starts up;
4 the burner starts up in the low flame stage: drive the burner to high flame stage, by means of the “high/low flame” thermostat
TAB
.
5 adjust the burner combustion values in the high flame stage as described in the following steps.
6 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;
7 acting on the pressure governor of the valves group, adjust the
gas flow rate in the high flame stage
as to meet the values
requested by the boiler/utilisation:
-
Multibloc MB-DLE:
the valve is adjusted by means of the
RP
regulator after slackening the locking screw
VB
by a number of
turns. By unscrewing the regulator
RP
the valve opens, screwing the valve closes. The pressure stabilizer is adjusted by operating
the screw
VS
located under the cover
C
. By screwing down the pressure is increased and by unscrewing it is reduced.
Note:
the
screw
VSB
must be removed only in case of replacemente of the coil.
- 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).
Pressure governor is factory-set. The setting values must be locally adapted to machine conditions. Important! Follow the instruc-
tions carefully!
8 .To adjust the
air flow rate in the high flame stage
, loose the
RA
nut and screw
VRA
as to get the desired air flow rate: moving
the rod
T
towards the air damper shaft, the air damper opens and consequently the air flow rate increases, moving it far from the
shaft the air damper closes and the air flow rate decreases.
Note:
once the procedure is perfomed, be sure that the blocking nut
RA
is fasten.
Go on adjusting the burner according to the model (double-stage, progressive, fully-modulating).
Berger STA12: a key is provided to move the cams.
Siemens SQN72: a key is provided to move cams I and IV, the other cams can be moved by means of screws.
Siemens VGD..
VR
T
C
VS T(VR)
RP
VB
VSB
Dungs Multibloc MB-DLE
TTENZIONE
VRA
VRA
RA
TR
