Burner Start-Up; Final Calibration Of The Pressure Switches - Riello 1106 T81 Installation, Use And Maintenance Instructions

Start-up, calibration and operation of the burner
5
5.3

Burner start-up

Feed electricity to the burner via the disconnecting switch on the
boiler panel.
Close the thermostats/pressure switches and turn the switch of
Fig. 28 to position "1".
Make sure that the lamps or testers connected to
the solenoids, or indicator lights on the solenoids
themselves, show that no voltage is present. If volt-
DANGER
age is present, stop the burner immediately and
check the electrical wiring.
Carry out the "Start-up procedure", as described on page 31.
5.4

Final calibration of the pressure switches

Air pressure switch
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. 29).
With the burner working 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 grad-
uated scale (Fig. 29). 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 back-
ground, between the two arrows).
Now check the correct start-up of the burner.
If the burner locks out again, turn the knob slightly anticlock-
wise.
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. 29.
The standard configuration is that with the air pressure switch
connected in absolute mode. Note the presence of a "T" con-
nection, not supplied.
In certain applications in strong depression situations, the con-
nection of the pressure switch does not allow it to change over.
In this case it is necessary to connect the pressure switch in dif-
ferential mode, applying a second tube between the air pres-
sure switch and the fan suction line mouth. In this case also,
the pressure gauge must be connected in differential mode, as
shown in Fig. 29.
22
GB
Connecting
D3951
the pressure
gauge with
the pressure
switch in ab-
solute mode
D7892
D7896
Fig. 28
Connecting
the pressure
gauge with the
pressure
switch in dif-
ferential mode
Fig. 29