Burner Calibration; Firing Output; 2Nd Stage Output - Riello RS 64 MZ Instrucciones De Instalación, Funcionamiento Y Mantenimiento

Burner off
Burner on
(A)
1 2
1st stage
2nd stage

BURNER CALIBRATION

The optimum calibration of the burner requires
an analysis of the flue gases at the boiler outlet.
Adjust successively:

1 - firing output

2 - 2nd stage burner output
3 - 1st stage burner output
4 - Intermediate outputs between 1st and 2nd
stage
5 - Air pressure switch
6 - Minimum gas pressure switch
1 - FIRING OUTPUT
According to EN 676 Regulations:
D469 Burners with max. output up to 120 kW
Firing can be performed at the maximum opera-
tion output level. Example:
• Max. operation output
• Max. firing output
Burners with max. output above 120 kW
Firing must be performed at a lower output than
the max. operation output. If the firing output
does not exceed 120 kW, no calculations are
required. If firing output exceeds 120 kW, the
regulations prescribe that the value be defined
according to the control box safety time "ts":
• for "ts" = 2s, firing output must be equal to or
lower than 1/2 of max. operation output.
• For "ts" = 3s, firing output must be equal to or
lower than 1/3 of max. operation output.
Example
MAX operation output of 600 kW.
Firing output must be equal to or lower than:
• 300 kW with ts = 2s
• 200 kW with ts = 3s
In order to measure the firing output:
- disconnect the plug-socket 23)(A)p.3 on the
ionization probe cable (the burner will fire and
then go into lock-out after the safety time has
elapsed).
- Perform 10 firings with consecutive lock-outs.
- 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 = 3s:
Vg = Qa (max. burner output) x n x ts
Vg: volume supplied upon ignitions carried out
3
(Sm
Qa: ignition output (Sm
n: number of ignitions (10)
ts: safety time (sec)
Example: for gas G 20 (9.45 kWh/Sm
ignition output 400 kW
corresponding to 47.6 Sm
After 10 firings with lock-outs, the delivery read
on the meter must be equal to or lower than::
Vg = 47.6 x 10 x 3 = 0.397 Sm

2 - 2ND STAGE OUTPUT

2nd stage output of the burner must be set
within the firing rate range shown on page 4.
In the above instructions we left the burner run-
ning in 1st stage operation. Now set switch 2)(A)
to the 2nd stage position: the servomotor will
open, simultaneously, the air gate valve and the
gas butterfly valve to 90°.
Gas calibration
Measure the gas delivery at the meter.
A guideline indication can be calculated from the
tables on page 5, simply read off the gas pres-
sure on manometer, see fig.(C) on page 9, and
follow the instructions on page 5.
- If delivery needs to be reduced, diminish out-
let gas pressure and, if it is already very low,
slightly close adjustment valve VR.
- If delivery needs to be increased, increase
outlet gas pressure.
10
3600
)
3
/h)
3
/h.
3
3600
: 120 kW
: 120 kW
3
):