24
the rod
TR
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. Do not change the position of the air damper
rods.
12 Only if necessary, change the combusiton head position: to let the burner operate at a lower output, loose the
VB
screw and move
progressively back the combustion head towards the MIN position, by turning clockwise the
VRT
ring nut. Fasten
VB
screw when
the adjustment is accomplished.
Attention!
if it is necessary to change the head position, repeat the air and gas adjustments described above.
13 the air and oil rate are now adjusted at the maximum power stage, go on with the point to point adjustement on the
SV
adjusting
cam as to reach the minimum output point.
14 as for the point-to-point regulation in order to set the cam foil shape, move the low flame microswitch (cam III) a little lower than the
maximum position (90°);
15 set the
TAB
thermostat to the minimum in order that the actuator moves progressively towards the low flame position;
16 move cam III (low flame) towards the minimum to move the actuator towards the low flame until the two bearings find the adjusting
screw that refers to a lower position: screw
V
to increase the rate, unscrew to decrease, in order to get the pressure as shown on
diagram in Fig. 20, according to the requested rate.
17 Move again cam III towards the minimum to meet the next screw on the adjusting cam and repeat the previous step; go on this way
as to reach the desired low flame point.
18 The low flame position must never match the ignition position that is why cam
III
must be set 20°- 30° more than the ignition posi-
tion.
Turn the burner off; then start it up again. If the adjustment is not correct, repeat the previous steps.
VRA
RA
TR
”MIN” position
”MAX” position
VB
VRT
ID
SC
RP
SV
V
