Riello GAS Series - Burner Adjustment

21
2915858
GB
Start-up, calibration and operation of the burner
6.5 Burner adjustment
The optimum adjustment of the burner requires an analysis of
flue gases at the boiler outlet.
Adjust in sequence:
1 Ignition output
2 Maximum burner output
3 Air pressure switch
4 Minimum gas pressure switch
6.5.1 Ignition output
According to EN 676:
Burners with MAX output up to 120 kW
Ignition can occur at the maximum operation output level. Exam-
ple:
• max. operation output: 120 kW
• max. ignition output: 120 kW
Burners with MAX output above 120 kW
Ignition must occur at a lower output than the max. operation out-
put.
If ignition output does not exceed 120 kW, no calculations are re-
quired. If ignition output exceeds 120 kW, the regulatory standard
sets that the value be defined according to the control box safety
time "ts":
- for "ts" = 2s, ignition output must be equal to or lower than 1/
2 of max. operation output;
- for "ts" = 3s, ignition output 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:
• 300 kW con ts = 2s
• 200 kW con ts = 3s
In order to measure the ignition output:
- Remove the UV sensor 29)(Fig. 5 on page 11) (the burner
starts and locks out after the safety time).
- 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 for-
mula:
Example for G 20 gas (10 kWh/Nm
3
):
Max operation output of 600 kW corresponding to 60 Nm
3
/h.
After 10 ignitions with their lockouts, the delivery indicated on the
meter must be equal to or less than:
60 : 360 = 0.166 Nm
3
.
6.5.2 Maximum burner output
MAX gas adjustment
Measure the gas flow rate.
- If you need to reduce it, close the 2nd stage gas valve a little.
- If you need to increase it, first fully open the 2nd stage gas
valve and then, if that is not enough, increase the gas outlet
pressure from the pressure regulator.
MAX air adjustment
Operate in sector 10)(Fig. 5 on page 11) with small movements.
In the end lock the sector well.
NOTE:
- When modifying the calibration of the pressure regulator to
obtain the desired output in the 2nd stage, you need to re-
check the ignition.
- For guidance purposes the maximum 2nd stage output can
be obtained, just read the gas pressure at the pipe coupling
12)(Fig. 5 on page 11) on the U pressure gauge (Fig. 21 on
page 20) and follow the instructions on page 18.
Nm
3
/h
(max. burner delivery)
360