Start-up, calibration and operation of the burner
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20096088
GB
5.8
Final calibration of the pressure switches
5.8.1
Air pressure switch
The air pressure switch is connected in differential (Fig. 45) 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. 44) 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.
5.8.2
Maximum gas pressure switch
Adjust the maximum gas pressure switch (Fig. 46) after making all
other burner adjustments with the maximum gas pressure switch
set to the end of the scale.
To calibrate the maximum gas pressure switch, open the tap and
then connect a pressure gauge to its pressure test point.
The maximum gas pressure switch must be regulated to a value no
higher than 30% of the measurement read on the gauge when the
burner is working at maximum output.
After making the adjustment, remove the pressure gauge and close
the tap.
Fig. 44
D3854
Fig. 45
20048352
PGM
PA
D3856
20181543
Fig. 46
