20019904
32
GB
Start-up, calibration and operation of the burner
5.6
Burner starting (fuel oil adjustment)
Turn the selection switch 36)(Fig. 5, page 13), to the “OIL” position.
Perform a visual setting (without taking a smoke test), which will be
perfected after setting the gas.
Operating control closes, the motor starts.
The pump 3)(Fig. 47) draws the fuel from the tank through the
piping 1) and pumps it under pressure for 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 de-energized solenoid valves 8) - 9) - 2) close the passage
to the nozzle.
Servomotor starts: 130° rotation to right, until contact is made
on cam 1.
The air damper is positioned on MAX. output.
Pre-purge stage with air delivery at MAX. output.
Servomotor rotates to left until contact is made on cam 3.
Air damper and pressure regulator are positioned on MIN out-
put.
Ignition electrode strikes a spark.
Solenoid valves 8) - 9) - 2) open; the fuel passes through the
piping 10) and filter 11), and enters the nozzle.
A part of the fuel is then sprayed out through the nozzle, ignit-
ing when it comes into contact with the spark: flame at a low
output level; the rest of the fuel passes through piping 12 at
the pressure adjusted by the regulator 13, then, through piping
7), it goes back into the tank.
The flame is established, spark goes out and burner runs.
The starting cycle ends.
5.6.1
Low oil pressure switch
The low oil pressure switch (Fig. 48) is factory set to 261 PSI
(18 bar).
If the oil pressure goes below this value in the delivery piping, the
pressure switch stops the burner.
Burner starts again automatically if the pressure goes above
261 PSI (18 bar) after burner start up.
5.6.2
High oil pressure switch
The high oil pressure switch (Fig. 48) is factory set to 43.5 PSI (3
bar).
If the oil pressure goes above this value in the return piping, the
pressure switch stops the burner.
Burner starts again automatically if the pressure goes down under
43.5 PSI (3 bar) after burner shut down.
If a loop circuit with Px pressure feeds the burner, the pressure
switch should be adjusted to Px + 43.5 PSI.
For the adjustment refer to Fig. 48.
Fig. 47
D10157
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+
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Fig. 48
D10627
