2509
9
GB
Combustion head settings indicated in the schedule are valid for most cases.
The setting of the fan output according to the installation should normally be done only through the air
damper. Should one subsequently want to retouch also the setting of the combustion head, with the
burner running, operate on the rod (1) with a 6 mm spanner (2) as follows:
Turn to the right: (sign
+
), in order to increase the
volume of air entering the combustion chamber and
thus diminishing its pressure.
There is a reduction of CO
2
and the adhesion of the
flame to the air diffuser disc improves. (Setting advisa-
ble for ignitions at low temperatures).
Turn to the left: (sign
–), in order to reduce the vol-
ume of air entering the combustion chamber and thus
increasing its pressure. The CO
2
improves and the
adhesion of the flame to the diffuser tends to reduce.
(This setting is not advisable for ignitions at low tem-
peratures).
In any case do not bring the combustion head setting
more than one point away from that indicated in the
schedule. One set-point corresponds to 3 turns of the
rod; a hole (3) at its end facilitates counting the num-
ber of turns.
AIR DAMPER ADJUSTMENT:
The settings indicated in the schedule refer to the burner with its metal cover fitted and the combustion
chamber with “zero” depression. These regulations are purely indicative.
Each installation however, has its own unpredictable working conditions: actual nozzle output; positive
or negative pressure in the combustion-chamber, the need of excess air, etc. All these conditions may
require a different air-damper setting.
It is important to take account of the fact that the
air output of the fan differs according to whether
the burner has its metal cover fitted or not.
Therefore we recommended to proceed as follows:
– adjust the air damper as indicated in the table;
– mount the cover, simply by means of the upper
screw;
– check smoke number;
– should it become necessary to modify the air out-
put, remove the cover by loosening the screw,
adjust the air damper, remount the cover and
finally recheck the smoke number.
NOTE:
When the burner works at a firing rate higher
than 9 kg/h for type 716T81 and 18 kg/h for type
717T81 remove the panel fitted inside the metal
cover. (See figure).
1
2
3
6
D8068
3
PANEL
S7350
