4.3
AIR DAMPER ADJUSTMENT,
Do not carry out the first ignition with the air damper lower than set point 1.
The air damper leaves the factory set for minimum output.
To vary the setting proceed as follows:
Loosen the nut (9) and the screws (8).
Once you have done, tighten the nut (9).
4.4
FIRING OUTPUT
The burner leaves the factory set for the minimum output.
The firing must occur at reducer output and not higher than 120 kW.
In order to measure the firing output:
– Disconnect the connector (CN1) on the ionization probe cable (see electrical wiring at page 8); the burn-
er will fire and then go into lock-out after the safety time (3s) has elapsed
– Perform 10 firings with consecutive lock-outs.
– On the meter read the total quantity of gas burned. This quantity must be equal to or lower than the
quantity here given:
3
0.10 Nm
for G20 (natural gas H)
3
0.10 Nm
for G25 (natural gas L)
3
0.03 Nm
for G31 (LPG).
4.5 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
Theoretical max. CO
GAS
0 % O
G 20
11.7
G 25
11.5
G 30
14.0
G 31
13.7
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.
4.6
AIR PRESSURE SWITCH
The air pressure switch is set after all other adjustments have been made. Begin with the switch at the
lowest setting. With the burner working at the minimum output, adjust the dial clockwise, increasing its
value until the burner shuts down.
Now reduce the value by one set point, turning the dial anti-clockwise.
Check for reliable burner operation, if the burner shuts down, reduce the value by a half set point.
Attention:
To comply with the EN 676 standard, the air pressure switch must operate when the CO value exceeds 1%
(10,000 ppm). To check this, insert a combustion analyser in the flue, slowly reduce the burner air setting and
verify that the burner shuts down by the action of the air pressure switch before the CO value exceeds 1%.
20094559
(fig. 8, page 9)
AIR EXCESS: max. output λ
Setting CO
2
λ = 1.2
2
9.7
9.5
11.6
11.4
≤ 1.2
%
2
λ = 1.3
9.0
8.8
10.7
10.5
10
GB
≤ 1.3
– min. output λ
NO
CO
mg/kWh
mg/kWh
≤
≤
100
170
≤
≤
100
170
≤
≤
100
230
≤
≤
100
230
CN1
_
+
D4631
x
SO