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6.6.1
Burner adjustment
The optimum adjustment of the burner requires an analysis of
flue gases at the boiler outlet.
Adjust in sequence:
1 - Output upon ignition
2 - MAX output
3 - MIN output
4 - Intermediate outputs between Min. and Max.
5 - Air pressure switch
6 - Maximum gas pressure switch
7 - Minimum gas pressure switch
6.6.2
Output upon ignition
Ignition must occur at a lower output than the max. operation out-
put. Regulations provide that the ignition output of this burner
must be equal to or less than 1/3 of the MAX operation output.
Example: MAX operation output of 600 kW.
Ignition output must be equal to or lower than:
200 kW with ts = 3 s.
In order to measure the ignition output:
➤ Disconnect the plug-socket 23)(Fig. 6 on page 14) on the
ionisation probe cable (the burner starts up and then goes
into lockout after the safety time has elapsed).
➤ Perform 10 ignitions with consecutive lockouts.
➤ Read the quantity of gas burned on the meter.
➤ This quantity must be equal to or lower than the quantity
given by the formula:
3
/h (max. burner delivery)
Sm
Example for G 20 gas (9.45 kWh/Sm
Max. operation output: 600 kW corresponding to 63.5 Sm
After 10 ignitions with their lockouts, the delivery indicated on the
meter must be equal to or less than: 63.5 : 360 = 0.176 Sm
Air adjustment
The air is adjusted by varying the angle of cam III)(Fig. 28) and
by using the selector 2)(Fig. 29). To adjust the cam of the servo-
motor, see Fig. 32 A).
6.6.3
Maximum output
The MAX output must be set within the firing rate indicated in
Fig. 3 on page 11.
In the above instructions we left the burner running at the MIN
output. Now press the "increase output" button 2)(Fig. 29 on
page 28), and keep it pressed until the servomotor has opened
the air damper and the gas butterfly valve.
Adjustment of gas delivery
Measure the gas delivery on the gas meter.
A rough indication can be obtained from Tab. J on page 25, just
read the gas pressure on the "U" pressure gauge (see Fig. 27 on
page 27) and follow the indications.
➤ If delivery needs to be reduced, diminish outlet gas pres-
sure; if it is already very low, slightly close the VR adjustment
valve.
➤ If delivery needs to be increased, increase the adjuster out-
let gas pressure.
Start-up, calibration and operation of the burner
360
3
):
Air adjustment
The air is adjusted by varying the angle of cam I)(Fig. 28 on
page 27) and by using the selector 2)(Fig. 29 on page 28). To ad-
just the cam of the servomotor, see Fig. 32 A).
20073575
Key (Fig. 31)
1
Cam
2
Adjustment screws
3
Servomotor
4
Graduated sector for gas butterfly valve
5
Air damper graduated sector
3
/h.
3
90
0
B
20074578
29
GB
Fig. 31
D
C
A
Fig. 32
20075006
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