Burner Calibration - Roca TECNO 190-L Instrucciones De Instalación, Funcionamiento Y Mantenimiento

(A)
Burner
Off
On
(B)
Stage
1 2
1°
2°
10

BURNER CALIBRATION

FIRING
Set switch 1)(B) to "ON".
During the first firing, during the passage from
the 1st to the 2nd stage, there is a momentary
lowering of the fuel pressure caused by the fill-
ing of the 2nd stage nozzle tubing. This lowering
of the fuel pressure can cause the burner to
lock-out and can sometimes give rise to pulsa-
tions.
Once the following adjustments have been
made, the firing of the burner must generate a
noise similar to the noise generated during oper-
ation. If one or more pulsations or a delay in fir-
ing in respect to the opening of the light oil
solenoid valve occur, see the suggestions pro-
vided on p. 14: causes 34 to 39.
OPERATION
The optimum calibration of the burner requires
an analysis of the flue gases at the boiler outlet
and interventions on the following points.
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• 1st and 2nd stage nozzles
See the information listed on page 5.
• Combustion head
The adjustment of the combustion head already
carried out need not be altered unless the 2nd
stage delivery of the burner is changed.
• Pump pressure
12 bar: This is the pressure calibrated in the fac-
tory which is usually sufficient for most pur-
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poses. Sometimes, this pressure must be
adjusted to:
10 bar in order to reduce fuel delivery. This
adjustment is possible only if the surrounding
temperature remains above 0°C. Never cali-
brate to pressures below 10 bar, at which pres-
sures the cylinders may have difficulty in
opening;
14 bar in order to increase fuel delivery or to
ensure firings even at temperatures of less than
0°C.
In order to adjust pump pressure, use the screw
5)(A)p. 9.
• 1st stage fan air gate valve
Keep the burner operating at 1st stage by set-
ting the switch 2)(B) to the 1st stage position.
Opening of the air gate valves 6)(A) must be
adjusted in proportion to the selected nozzle:
the index 8)(A) must be aligned with the notch
indicated on the graduated sector 7)(A). This
adjustment is achieved by turning the hex ele-
ment 2)(A):
- towards the right direction (- sign) the opening
is reduced;
- towards the left direction (+ sign) the opening
increases.
• 2nd stage fan air gate valve
Set switch 2)(B) to the 2nd stage position and
adjust the air gate valve 6)(A) by turning the hex
element 4)(A), after having loosened the ring nut
3)(A).
NOTE: in order to facilitate adjustment of hex
elements 2) and 4)(A), use a 3 mm Allen key
5)(A).