Pressure Switch Adjustment; Air Pressure Switch - Check Co; Maximum Gas Pressure Switch; Minimum Gas Pressure Switch - Riello RS 300/EV BLU Installation, Use And Maintenance Instructions

6.6

Pressure switch adjustment

6.6.1

Air pressure switch - check CO

Adjust the air pressure switch (Fig. 31) after performing all other
burner adjustments with the air pressure switch set to the start of
the scale.
With the burner operating at MIN output, insert a combustion
analyser in the stack, slowly close the suction inlet of the fan (for
example, with a piece of cardboard) until the CO value does not
exceed 100 ppm.
Slowly turn the appropriate knob clockwise until the burner goes
into lockout.
Check the indication of the arrow pointing upwards on the gradu-
ated scale. Turn the knob clockwise again, until the value shown
on the graduated scale corresponds with the arrow pointing
downwards, and so recovering the hysteresis of the pressure
switch (shown by the white mark on a blue background, between
the two arrows).
Now check the correct start-up of the burner.
If the burner locks out again, turn the knob anti-clockwise a little
bit more.
On RS 300-400-500/EV BLU burners the air pressure switch is
fitted in a "differential" mode, that is, with two pipes connected to
the specific pressure test points "+" and "-" 22)-23)(Fig. 4 on
pag. 12).
On RS 650-800/EV BLU burners the air pressure switch is fitted
in an "absolute" mode, that is, connected only to the pressure test
point "+" 22Fig. 4 on pag. 12).
6.6.2

Maximum gas pressure switch

Adjust the maximum gas pressure switch (Fig. 32) after perform-
ing all other burner adjustments with the maximum gas pressure
switch set to the end of the scale.
With the burner operating at maximum output, lower adjustment
pressure by slowly turning the relative knob anticlockwise until
the burner locks out.
Turn the knob clockwise by 0.2 kPa (2 mbar) and repeat the start-
up of the burner.
If the burner locks out again, turn the knob clockwise again by 0.1
kPa (1 mbar).
6.6.3

Minimum gas pressure switch

Adjust the minimum gas pressure switch (Fig. 33) after perform-
ing all the other burner adjustments with the pressure switch set
to the start of the scale.
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
burner start-up to ensure it is uniform.
If the burner locks out again, turn the knob anticlockwise again by
0.1 kPa (1 mbar).
6.6.4

PVP pressure switch kit

Adjust the pressure switch for the leak detection control (Fig. 34)
according to the instructions supplied with the kit.
20123768
Start-up, calibration and operation of the burner
1 kPa = 10 mbar
WARNING
28 GB
D3854
D3856
D3855
D3855
Fig. 31
Fig. 32
Fig. 33
Fig. 34