Riello RS 34/1 MZ, Installation, Use And Maintenance Manual, Page: 14 / 48

12
BURNER CALIBRATION
The optimum calibration of the burner requires
an analysis of the exhaust gases at the boiler
outlet.
Adjust successively:
1 - Maximum output;
2 - Air pressure switch;
3 - Minimum gas pressure switch.
DETERMINATION OF OUTPUT UPON FIR-
ING (MINIMUM)
According to the regulation EN 676.
Burners with MAX output up to 120 kW
Firing can be performed at the maximum opera-
tion output level. Example:
• max. operation output
: 120 kW
• max. firing output : 120 kW
Burners with MAX output above 120 kW
Firing must be performed at a lower output than
the max. operation output.
If firing output does not exceed 120 kW, no cal-
culations are required. If firing output exceeds
120 kW, the regulations prescribe that the value
be defined according to the control box "ts"
safety time:
for "ts" = 3s, firing output must be equal to, or
lower than, 1/3 of max. operation output.
Example
MAX operation output of 450 kW.
The firing output must be equal to, or less than,
150 kW with ts = 3s
In order to measure the firing output:
- disconnect the plug-socket 23)(A)p.4 on the
ionisation probe cable (the burner will fire and
then go into lockout after the safety time has
elapsed).
- Perform 10 firings with consecutive lockouts.
- Read, on the meter, the quantity of gas
burned.
This quantity must be equal to, or lower than,
the quantity given by the formula, for ts = 3s:
Vg: volume supplied upon firings carried out
(Sm
3
)
Qa: firing output (Sm
3
/h)
n: number of firings (10)
ts : safety time (sec)
Example for gas G 20 (9.45 kWh/Sm
3
):
firing output 150 kW
corresponding to 15.87 Sm
3
/h.
After 10 firings with lockout, the output indicated
on the meter must be equal to, or less than
:
1 - MAXIMUM OUTPUT
The maximum output of the burner must be set
within the firing rate range shown on page 5.
Adjusting gas delivery
Measure the delivery of gas from the gas meter.
A guideline indication can be calculated from the
tables on page 6, simply read off the gas pres-
sure on the manometer, see fig.(C) on page 11,
and follow the instructions on pages 6 - 7.
- If delivery needs to be reduced, diminish out-
let gas pressure and, if it is already very low,
slightly close adjustment valve VR2.
- If delivery needs to be increased, increase
outlet gas pressure.
Adjusting air delivery
Adjust the fan air damper by using the indexed
selector 1)(A) after having loosened the screw
2)(A).
(A)
D593
Vg =
3600
Qa (max. burner output) x n x ts
Vg =
3600
15,87 x 10 x 3
= 0,132 Sm
3