Riello RS 160/M BLU, Instruction Manual

Page: 32 / 52

20168488 30 GB
Start-up, calibration and operation of the burner
6.6 Final adjustment of the pressure switches
6.6.1 Air pressure switch
Adjust the air pressure switch (Fig. 32) after performing all other
burner adjustments with the air pressure switch set to the start of
the scale.
With the burner operating at minimum 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
graduated scale. Turn the knob clockwise again, until the value
shown on the 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 anticlockwise a little
bit more. During these operations it may be useful to measure the
air pressure with a pressure gauge.
The connection of the pressure gauge is shown in Fig. 32.
The standard configuration is that with the air pressure switch
connected in absolute mode.
Note the presence of a “T” connection, not supplied.
In certain applications in strong depression situations, the
connection of the pressure switch does not allow it to change
over.
In this case it is necessary to connect the pressure switch in
differential mode, applying a second tube between the air
pressure switch and the fan suction line mouth.
In this case also, the pressure gauge must be connected in
differential mode, as shown in Fig. 32.
6.6.2 Maximum gas pressure switch
Adjust the maximum gas pressure switch (Fig. 33) after
performing 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 the
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 again clockwise by 0.1
kPa (1 mbar).
6.6.3 Minimum gas pressure switch
Adjust the minimum gas pressure switch (Fig. 34) after
performing all the other burner adjustments with the pressure
switch set to the start of the scale.
With the burner operating at maximum output, increase
adjustment pressure by slowly turning the relative knob clockwise
until the burner stops.
Then turn the knob anticlockwise by 0.2 kPa (2 mbar) and repeat
burner start-up to ensure it is operating regularly.
If the burner locks out again, turn the knob again anticlockwise by
0.1 kPa (1 mbar).
After adjusting the burner, set the switch to “
AUT ” position.
ATTENTION
1 kPa = 10 mbar
Fig. 32
1)
2)
D890
D3854
Fig. 33
D3856
Fig. 34
D3855