Riello 663 M - Servomotor; Pressure Switch Adjustment; Oil Pressure Switch

20167399
26
GB
Start-up, calibration and operation of the burner
8.3 Servomotor
The servomotor simultaneously adjusts the air damper
11)(Fig. 29 on page 25) and the pressure variator 9) by means of
a double variable profile cam, 4) and 7). The servomotor's
rotation angle is 90° in 24 s.
Do not alter the factory setting for the 4 cams; just check that they
are as specified below:
8.4 Pressure switch adjustment
8.4.1 Oil pressure switch
The pressure switch 11)(Fig. 5 on page 11) is adjusted in the
factory at 3 bar. If the light oil pressure reaches this value in the
return duct, the pressure switch stops the burner.
The burner restarts automatically if the pressure goes back to
less than 3 bar after stopping.
If the burner is fed by a loop circuit with a pressure of Px, the
pressure switch must be adjusted at Px + 3 bar.
To adjust the pressure switches, use a tool to operate the
adjustment screw, see Fig. 33.
Cam I: 90° Limits rotation toward maximum
position.
Cam II: 0° Limits rotation toward minimum
position.
With burner off, the air damper must
be closed: 0°.
Cam III: 15° Adjusts the ignition position and the
MIN output.
Cam IV: not used.
Fig. 32
D790
Fig. 33
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