20017633
10
GB
4.3
AIR DAMPER ADJUSTMENT,
(fig. 10)
First start-up must always be performed, adjusting screw (12), so
that the 1
st
stage air damper position pointer is beyond mark 1,
(factory setting mark 1).
To adjust, proceed as follows:
Take the burner to 2
nd
stage by closing the
T6-T8
connection found
in the 4-pin plug (
X4
, wiring on page 8).
Fan thrust causes the air damper to go to the 2
nd
-stage position with
reference to the factory setting (screw 8 on mark 3).
Loosen nut (9) and turn screw (8) to adjust 2
nd
-stage air flow (see
CO
2
values given in the table below).
Take the burner to 1
st
stage by opening the
T6-T8
connection found
in the 4-pin plug (
X4
, page 8).
Adjust 1
st
stage by turning screw (12), loosening (
clockwise
) nut (11)
first, referring to the table below for CO
2
values.
Once you have achieved the optimal setting, tighten (
anticlock-
wise
) nut (11). When the burner stops, the air damper closes
automatically under its own weight until maximum negative flue
pressure is 0.5 mbar.
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.
Example for BS3D: 2
nd
stage output required 140 kW;
Minimum 1
st
stage output no less than 70 kW.
Whatever the case, the burner's minimum 1
st
stage output must not be lower than the value indicated in
the operating range.
Example for BS3D: 2
nd
stage output required 110 kW;
Minimum 1
st
stage output no less than 65 kW (minimum in operating range page 4).
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:
IONIZATION CURRENT
The minimum current necessary for the con-
trol box operation is 5 µA.
The burner normally supplies a higher cur-
rent value, so that no check is needed. Any-
way, if you want to measure the ionization
current, you have to open the connector
(CN1)
(see electrical scheme page 8) fitted
on the wire and insert a microammeter.
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
8
9
12
11
0
6
1
2
3
4
5
Fig. 10
ATTENTION
D4631
+
_
SO
CN1
