3387
12
GB
REMOVING HEAD ASSEMBLY,
(see Fig. 10)
To remove the head assembly, carry out the following operations:
Remove the head-holder assembly (1), after taking away the screws (7), disconnect the connections (3 and
5), extract the small tube (4) and loosen the screws (8).
Do not modify the setting position of the bracket-elbow during the disassembly.
REASSEMBLY OF THE HEAD SYSTEM,
(see Fig. 10)
Warning
During the reassembly of the system, tighten the screws (7) completely
(without locking them)
;
then lock them with a torque wrench setting of 3 - 4 Nm
.
Control that, during the working, there are not gas losses coming from the screws.
If casually the pressure test point (9) looses, fix correctly and be sure that the hole (F), placed in the external
side of the head-assembly (1) turns towards the lower part.
4.3
SETTING OF THE SERVOMOTOR,
(see Fig. 10)
CAM I
By adjusting the micrometric screw, cam
I
regulates the
position of the 1
st
stage air damper (factory setting ref-
erence value 25°).
CAM II and III
Cam
II
regulates the position of the 2
nd
stage air damper
(factory setting reference value 50°, do not exceed 65°).
Cam
III
is used to open the 2
nd
stage valve (factory set-
ting reference value 35°).
It must always be at least 15° in front of cam
II
.
CAM V
Cam
V
is factory set (factory setting reference value 90°).
Do not modify this setting for any reason
.
To adjust 1
st
and 2
nd
stage output, follow the instructions below:
Output ratio between 1
st
and 2
nd
stage must be no more than 1:2.
Whatever the case, the burner's minimum 1
st
stage output must not be lower than the value indicated in
the operating range.
4.4
COMBUSTION CHECK
It is advisable to set the burner according to the type of gas used and following the indications of the table:
EN 676
AIR EXCESS: max. output
1.2
– min. output
1.3
GAS
Theoretical max. CO
2
0 % O
2
Setting
CO
2
%
CO
mg/kWh
NO
x
mg/kWh
= 1.2
= 1.3
G 20
11.7
9.7
9.0
100
170
G 25
11.5
9.5
8.8
100
170
G 30
14.0
11.6
10.7
100
230
G 31
13.7
11.4
10.5
100
230
Micrometric screws
D4360
Fig. 11
FIRST STAGE
SECOND STAGE
ATTENTION
