Start-up, calibration and operation of the burner
29
20109674
GB
5.4
Final calibration of the pressure switch
5.4.1
Air pressure switch
The air pressure switch is connected in differential (Fig. 39) and is
activated by both the negative pressure of the air intake and the air
pressure from the fan.
Adjust the air pressure switch (Fig. 38) after having performed all
other burner adjustments with the air pressure switch set to the
min. of the scale.
With the burner operating at low fire, adjust the pressure switch by
slowly turning the relative knob clockwise until the burner locks out.
Then turn the knob counter-clockwise about 20% of the set point
and start-up the burner again to ensure the set point is correct.
If the burner locks out again, turn the knob counter-clockwise a little
bit more.
5.4.2
Maximum oil pressure switch
The high oil pressure switch 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, see Fig. 40.
Fig. 38
D3854
Fig. 39
20048352
-
+
-
Fig. 40
D10627
