Riello 3897304, Installation, Use And Maintenance Instructions

Page: 26 / 48

20098687
24 GB
Start-up, calibration and operation of the burner
6.1 Notes on safety for the first start-up
6.2 Adjustments prior to ignition
The adjustment of the combustion head, air and gas has already
been described in the paragraph
“Combustion head adjust-
ment” on page 17.
In addition, the following adjustments must also be made:
➤
open the manual valves upline of the gas train.
➤ Adjust the minimum gas pressure switch to the start of the
scale (Fig. 30).
➤ Adjust the air pressure switch to the start of the scale
(Fig. 28).
➤ Purge the air from the gas line. We recommend using a plas-
tic tube routed outside the building and to purge air until gas
is smelt.
➤ Fit a U-type pressure gauge (Fig. 23) to the gas pressure
test point on the pipe coupling. Used to roughly calculate
MAX burner output using the tables Tab. H on page 20.
➤ Connect two lamps or testers parallel to the two gas line
solenoids VR and VS in order to check the exact moment at
which voltage is supplied. This operation is unnecessary if
each of the two solenoids is equipped with a pilot light that
signals voltage passing through.
6.3 Servomotor
The servomotor (Fig. 24) provides simultaneous adjustment for
the air damper, by means of the variable profile cam and the gas
butterfly valve.
The angle of rotation of the servomotor is equal to the angle on
the graduated sector controlling the gas butterfly valve.
The servomotor rotates 90° in 24 s.
Cam I: 90°
Limits rotation toward maximum position.
When the burner is at MAX output, the gas butterfly valve must
be fully open: 90°.
Cam II: 0°
Limits rotation toward minimum position.
When the burner is shut down, the air damper and gas butterfly
valve must be closed: 0°.
Cam III: 20°
Adjusts the ignition position and the MIN output.
Cam IV: integrated to cam III.
6 Start-up, calibration and operation of the burner
WARNING
The first start-up of the burner must be carried out
by qualified personnel, as indicated in this manual
and in compliance with the standards and regula-
tions of the laws in force.
WARNING
Check the correct working of the adjustment, com-
mand and safety devices.
CAUTION
Before starting up the burner, it is good practice to
adjust the gas train so that ignition takes place in
conditions of maximum safety, i.e. with gas deliv-
ery at the minimum.
Fig. 23
D789
WARNING
Do not alter the factory setting for the 4 cams; just
check that they are as indicated below.
Fig. 24
D790