PART III: OPERATION
31
Adjusting the combustion head
Only if necessary, change the combusiton head position: to let the burner operate at a lower output, loose the
VB
screw and move pro-
gressively back the combustion head towards the MIN position, by turning clockwise the
VRT
ring nut. Fasten
VB
screw when the
adjustment is accomplished.
Center head holes gas flow regulation (natural gas burners)
To adjust the gas flow, partially close the holes, as follows:
1
loosen the three
V
screws that fix the adjusting plate
D
;
2
insert a screwdriver on the adjusting plate notches and let it move CW/CCW as to open/close the holes;
3
once the adjustmet is performed, fasten the
V
screws.
The adjusting plate correct position must be regulated in the plant during the commissioning.
The factory setting depends on the type of fuel for which the burner is designed:
For natural gas burners, plate holes are fully opened
Center head holes gas flow regulation (LPG burners)
To adjust the gas flow, partially close the holes, as follows:
1
loosen the three
V
screws that fix the adjusting plate
D
;
2
insert a screwdriver on the adjusting plate notches and let it move CW/CCW as to open/close the holes;
3
once the adjustmet is performed, fasten the
V
screws.
The adjusting plate correct position must be regulated in the plant during the commissioning.
9xA
series
: 1,5 mm 5xxA
series
: 1,3 mm
Attention! if it is necessary to change the head position, repeat the air and fuel adjustments described above.
CAUTION: perform these adjustments once the burner is turned off and cooled.
VRT
VB
“MAX” head position
”MIN” head position
V
D
A:
opened holes
B:
closed holes
B
A
V
D
A:
opened holes
B:
closed holes
B
A
