Burner Operation - Riello 3470210 Installation, Use And Maintenance Instructions

TL
TR
2°
1°
0
LED
*
RMO
TL
LED
*
RMO
*
Off Yellow
For further details see page 14.
(A)
(B)
A
A
D3938
D3939
Green Red
D3912
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 piston
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 sole-
noid valves 8) - 11), 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 : The solenoid valves open 8); 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been replaced by a jumper wire, the 2nd stage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
passes on to the control device TR that controls
boiler temperature or pressure.
• When the temperature or the pressure
increases until the control device TR opens,
solenoid valve 11) closes, and the burner
passes from the 2nd to the 1st stage of opera-
tion.
• 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
remote control device TL opens, solenoid
valve 8) closes, the flame immediately goes
out. The fan's air damper valve closes com-
pletely.
System 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 lockout
within 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 sec-
ond and automatically attempts to start again by
repeating the starting cycle.