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

TL
TR
2°
1°
0
LED
*
RMO
TL
LED
*
RMO
*
Off Yellow
For further details see page 14.
(A)
TECNO 38-L and 50-L
(B)
D480
A
A
D3280
D3281
Green Red
TECNO 28-L
12

BURNER OPERATION

BURNER STARTING (A) - (B)
Starting phases with progressive time intervals
shown in seconds:
• Control device TL closes.
After about 3s:
• 0 s : The control box starting cycle begins.
• 2 s : The fan motor starts.
• 3 s : The ignition transformer is connected.
The pump 3) sucks the fuel from the tank
through the piping 1) and the filter 2) and
pumps it under pressure to delivery. The pis-
ton 4) rises and the fuel returns to the tank
through the piping 5) - 7). The screw 6) closes
the by-pass heading towards suction and the
solenoid valves 8) - 11) - 16), de-energized,
close the passage to the nozzles.
The hydraulic cylinder 15), piston A, opens the
air gate valve: pre-purging begins with the 1st
stage air delivery.
• 22 s : Solenoid valves 8) and 16) open and the
fuel passes through the piping 9) and filter 10)
and is then sprayed out through the nozzle,
igniting when it comes into contact with the
spark. This is the 1st stage flame.
• 29 s: The ignition transformer switches off.
• 36 s: If the control device TR is closed or has
been replaced by a jumper wire, the 2nd stage
solenoid valve 11) is opened and the fuel
enters the valve 12) and raises the piston
which opens two passages: one to piping 13),
filter 14), and the 2nd stage nozzle, and the
other to the cylinder 15), piston B, that opens
the fan air gate valve in the 2nd stage. 
The starting cycle comes to an end.
STEADY STATE OPERATION
System equipped with one control device TR
Once the starting cycle has come to an end, the
command of the 2nd stage solenoid valve pass-
es on to the control device TR that controls boiler
temperature or pressure.
• When the temperature or the pressure increas-
es until the control device TR opens, solenoid
valve 11) closes, and the burner passes from
the 2nd to the 1st stage of operation.
• When the temperature or pressure decreases
until the control device TR closes, solenoid
valve 11) opens, and the burner passes from
the 1st to the 2nd stage of operation, and so on.
• The burner stops when the demand for heat is
less than the amount of heat delivered by the
burner in the 1st stage. In this case, the control
device TL opens, and solenoid valves 8)-16)
close, the flame immediately goes out. The
fan's air gate valve closes completely.
Systems not equipped with control device
TR (jumper wire installed)
The burner is fired as described in the case
above. If the temperature or pressure increase
until control device TL opens, the burner shuts
down (Section A-A in the diagram).
When the solenoid valve 11) de-energizes, the
piston 12) closes the passage to the 2nd stage
nozzle and the fuel contained in the cylinder 15),
piston B, is discharged into the return piping 7).
FIRING FAILURE
If the burner does not fire, it goes into lock-out with-
in 5 s of the opening of the 1st nozzle valve and 30
s after the closing of control device TL.
The control box red pilot light will light up.
UNDESIRED SHUTDOWN DURING OPERA-
TION
If the flame goes out during operation, the burner
shuts down automatically within 1 second and
automatically attempts to start again by repeat-
ing the starting cycle.