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6.3
Burner start-up
Feed electricity to the burner via the disconnecting switch on the
boiler panel.
Close the thermostats/pressure switches and turn the switch to
Fig. 30 " AUTO" .
Make sure that the lights or testers connected to
the solenoids, or the pilot lights on the solenoids
themselves, indicate that no voltage is present.
DANGER
If voltage is present, then immediately stop the
burner and check the electrical wiring. When the
burner starts, check the direction of the rotation of
the motor, as shown in Fig. 30.
As soon as the burner starts up, go in front of the
cooling fan of the fan motor and check it is rotating
anticlockwise.
If this is not the case:
place the switch of Fig. 30 in position "0" and
wait for the control box to carry out the
switch-off phase;
disconnect the burner from the electrical sup-
ply;
invert the phases on the three-phase power
supply.
6.4
Burner adjustment
6.4.1
Firing output
According to the regulation EN 676.
Burners with MAX output up to 120 kW
Ignition can be performed at the maximum operation output level.
Example:
–
max. operation output:
–
max. firing output:
Burners with MAX output above 120 kW
Ignition must be performed at a lower output than the max. oper-
ation output.
If ignition output does not exceed 120 kW, no calculations are re-
quired. If ignition output exceeds 120 kW, the regulations pre-
scribe that the value be defined according to the control box
safety time "ts":
for ts = 3 s, ignition output must be equal to, or lower than, 1/3 of
max. operation output.
Example:
MAX operation output of 450 kW.
The ignition output must be equal to, or less than, 150 kW with
ts = 3 s
In order to measure the ignition output:
disconnect the plug-socket 7)(Fig. 5 at page 12) on the ioni-
sation probe cable (the burner will fire and then go into lock-
out after the safety time has elapsed);
perform 10 ignitions with consecutive lockouts;
on the meter, read the quantity of gas burned:
this quantity must be equal to, or lower than, the quantity
given by the formula, for ts = 3 s:
Qa (max. burner delivery) x n x ts
Vg =
3600
Vg
volume supplied in ignitions carried out (Sm
3
Qa
ignition delivery (Sm
n
number of ignitions (10)
Start-up, calibration and operation of the burner
120 kW
120 kW
3
)
/h)
20110442
ts
safety time (sec)
Example for gas G 20 (9.45 kWh/Sm
ignition output 150 kW corresponding to 15.87 Sm
After 10 ignitions with lockout, the delivery indicated on the meter
must be equal to, or less than:
15.87 x 10 x 3
Vg =
3600
6.4.2
Maximum output
The MAX output must be set within the firing rate (Fig. 2 at
page 10).
Gas adjustment
Measure the gas delivery on the meter.
As a general rule, this value can be found on Tab. O at page 27,
just read the gas pressure on the pressure gauge (Fig. 37 at
page 37) and follow the indications given on page 27.
–
If it is necessary to reduce it, lower the output gas pressure
via the pressure adjuster located beneath the gas valve.
–
If it needs to be increased, increase the output gas pres-
sure via the adjuster.
Air adjustment
If necessary vary the degrees of the air servomotor.
6.4.3
Minimum output
The MIN output must be set within the firing rate (Fig. 2 at
page 10).
31
GB
3
) :
3
= 0.132 Sm
0
AUTO
Fig. 30
3
/h .
20156417
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