Burner Calibration - Baxi TECNO 28-L Instrucciones De Instalación, Funcionamiento Y Mantenimiento

(A)
Burner
Off
On
(B)
TECNO 28-L TECNO 38-L TECNO 50-L
 
GPH GPH
2,00 14 2,50 12
2,25 17 3,00 18
2,50 20 3,50 20
3,00 22 4,00 22
3,50 24 4,50 23
5,00 26
TECNO 28-L TECNO 38-L TECNO 50-L
kg/h mbar kg/h mbar
14 6,0 20 7,0
16 6,3 22 7,0
18 6,6 24 7,0
20 6,8 26 7,0
22 7,1 29 7,0
24 7,6 32 7,0
26 8,4 35 8,0
28 8,8 38 9,4
In the event of a burner lockout, more than two consecutive burner reset opera-
tions could cause damage to the installation. On the third lockout, contact the Af-
tersales Service.
If further lockouts or burner faults occur, interventions must only be made by
qualified, authorised personnel (as indicated in this manual, and in compliance
with the laws and regulations currently in force).
Stage
1 2
1st STAGE
 = Notch Nr.

GPH
3,00 12
3,50 15
4,00 18
4,50 21
5,00 23
5,50 27
6,00 28
2nd STAGE
mbar = air pressure in 1) with zero
kg/h mbar
pressure in 2)
25 6,1
29 6,2
33 6,4
(1) With shutter 4)(C)p.5 retracted
37 6,5
41 6,6
45 8,0
50 10,1
50 9,1
(1)
D468
1st
2nd
D469
(C)
(D)
11

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 filling
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 pulsations.
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 firing
in respect to the opening of the light oil solenoid
valve occur, see the suggestions provided on p.
15: causes 34 to 42.
OPERATION
The optimum calibration of the burner requires
an analysis of the flue gases at the boiler outlet
and interventions on the following points:
• 1st and 2nd 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 purposes.
Sometimes, this pressure must be adjusted to:
10 bar in order to reduce fuel delivery. This ad-
justment is possible only if the surrounding tem-
perature remains above 0°C. Never calibrate to
pressures below 10 bar, at which pressures the
cylinders may have difficulty in opening;
14 bar in order to increase fuel delivery or to en-
sure firings even at temperatures of less than
0°C.
In order to adjust pump pressure, use the screw
5)(A), p. 10.
• 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 valve 1)(A) must be
adjusted in proportion to the selected nozzle:
the index 7)(A) must be aligned with the speci-
fied in table (C). This adjustment is achieved by
turning the hex element 4):
- in rh direction (- sign) the opening is reduced;
- in lh direction (+ sign) the opening increases.
Example
TECNO 38-L - 1st stage nozzle 3.00 GPH:
18° notch aligned with index 7(A).
When the adjustment is terminated lock the hex
element 4) with the ring nut 3).
• 2nd stage fan air gate valve
Set switch 2)(B) to the 2nd stage position and
adjust the air gate valve 1)(A) by turning the hex
element 6)(A), after having loosened the ring nut
5)(A).
Air pressure at attachment 1)(D) must be
approximately the same as the pressure speci-
fied in table (D) plus the combustion chamber
pressure measured at attachment 2). Refer to
the example in the adjacent figure.
NOTE: in order to facilitate adjustment of hex
elements 4) and 6)(A), use a 3 mmc Allen key
8)(A).