Pressure Switch Adjustment; Air Pressure Switch; Maximum Gas Pressure Switch; Minimum Gas Pressure Switch - Riello DB 2 LSE FGR Installation, Use And Maintenance Instructions

5.9

Pressure switch adjustment

5.9.1

Air pressure switch

Adjust the air pressure switch after performing all other burner
adjustments with the air pressure switch set to the start of the
scale (Fig. 31).
With the burner operating at MAX. output, increase adjustment
pressure by slowly turning the relative knob clockwise until the
burner locks out.
Then turn the knob anti-clockwise by about 20% of the adjusted
value and
check the burner starts up correctly. If the burner locks out again,
turn the knob anti-clockwise a little bit more.
In conformity with current standards, the air pres-
sure switch must prevent the CO in the flue gases
exceeding 1% (10,000 ppm).
WARNING
5.9.2

Maximum gas pressure switch

djust the maximum gas pressure switch (Fig. 32) 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.
5.9.3

Minimum gas pressure switch

Adjust the minimum gas pressure switch after performing all the
other burner adjustments with the pressure switch set to the start
of the scale (Fig. 33).
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 anticlockwise by 0.2 kPa
(2 mbar) and repeat the burner start-up to ensure it is operating
regularly.
If the burner locks out again, turn the knob anticlockwise again by
0.1 kPa (1 mbar).
1 kPa = 10 mbar
WARNING
5.9.4

Maximum oil pressure switch

Check that the oil pressure switches have intervened correctly.
Turn the adjustment screw (Fig. 34) to check that the pressure
switches have intervened.
Decreasing the maximum calibration of the oil pressure switch,
the burner should go into lockout.
Once the controls have been carried out, reset the factory setting
2 bar.
Start-up, calibration and operation of the burner
D3854
D3856
20079898
29 GB
Fig. 31
PA
20183681
PGM
Fig. 32
Fig. 33
D3855
Fig. 34
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