Table of Contents
Advertisement
6.10
Adjustment pressure switches
6.10.1 Air pressure switch - CO check
Adjust the air pressure switch after having performed all other
burner adjustments with the air pressure switch set to the start of
the scale (Fig. 38).
With the burner operating at minimum output, increase adjust-
ment pressure by slowly turning the relative knob clockwise until
the burner locks out.
Then turn the knob anti-clockwise by about 20% of the set point
and repeat burner starting to ensure it is correct.
If the burner locks out again, turn the knob anti-clockwise a little
bit more.
As a rule, the air pressure switch must prevent the
air pressure from lowering below 80% of the ad-
justment value as well as preventing the CO in the
WARNING
fumes from exceeding 1% (10,000 ppm).
To check this, insert a combustion analyser into the
chimney, slowly close the fan suction inlet (for exam-
ple with cardboard) and check that the burner locks
out, before the CO in the fumes exceeds 1%.
The air pressure switch is fitted in an "absolute" mode, that is,
connected only to the pressure test point "+" 22)(Fig. 4).
6.10.2 Max. gas pressure switch
Adjust the maximum gas pressure switch after having performed
all the other burner adjustments with the pressure switch set at
the end of the scale (Fig. 39).
With the burner operating at maximum output, decrease adjust-
ment pressure by slowly turning the relative knob anti-clockwise
until the burner locks out.
Then turn the knob clockwise by 0,2 kPa (2 mbar) and repeat
burner starting to ensure it is uniform.
If the burner locks out again, turn the knob anti-clockwise again
by 0,1 kPa (1 mbar).
6.10.3 Min. gas pressure switch
Adjust the minimum gas pressure switch after having performed
all the other burner adjustments with the pressure switch set at
the start of the scale (Fig. 40).
With the burner operating at maximum output, increase adjust-
ment pressure by slowly turning the relative knob clockwise until
the burner locks out.
Then turn the knob anti-clockwise by 0,2 kPa (2 mbar) and re-
peat burner starting to ensure it is uniform.
If the burner locks out again, turn the knob anti-clockwise again
by 0,1 kPa (1 mbar).
1 kPa = 10 mbar
WARNING
Start-up, calibration and operation of the burner
33
GB
D3854
D3856
D3855
Fig. 38
Fig. 39
Fig. 40
20010305
Advertisement
Table of Contents
