35
20140894
GB
Start-up, calibration and operation of the burner
7.9
Burner operation
7.9.1
Burner starting
- When the control device TL closes, the control box
programmes the starting phase.
- 0 sec. time:
The control device TL closes.
- After 27 sec.:
The motor starts and the ignition transformer is connected. Pre-
purging begins with the 1st stage air delivery.
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 bypass heading towards suction
and the solenoid valves 8) and 11), de-energized, close the
passage to the nozzles.
- After 47 sec.:
Solenoid valve 8) opens 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.
- After 54 sec.:
The ignition transformer switches off. 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closed or has been replaced by a jumper wire, the 2nd stage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) that opens the fan air gate valve in the
2nd stage.
- After 60 sec.:
The starting cycle comes to an end.
7.9.2
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, the burner passes from the 2nd to
the 1st stage of operation.
–
When the temperature or pressure decreases until the con-
trol device TR closes, 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 the solenoid valve 8)
closes, the flame immediately goes out. The fan's air gate
valve remains in the 1st stage position.
Systems not equipped with control device TR (which has
been replaced by a jumper)
The burner is fired as described in the case above. If the temper-
ature 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) is discharged into the return piping 7) for the PRESS
1-2 G Models and into the suction line 16) for the PRESS 3 G.
Fig. 36
D380
Fig. 37
D381
Summary of Contents for PRESS 1G
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