20017376
12
GB
Operation
6.1
Notes on safety for the first start-up
6.2
Adjustment before first firing
The following to be made are:
Open the manual valves located upline from the gas train.
Bleed the air from the gas pipes.
6.3
Burner start-up
Switch on the burner's power and close the thermostat.
The burner starts in pre-purging mode at top speed. Speed sub-
sequently decreases to the START value and the burner fires.
If however the fan starts up but no flame has appeared at the end
of the safety period, the burner goes into lockout.
Reset and wait for a new start-up attempt.
If the burner still does not fire, the problem may be that gas is not
reaching the combustion head within the 3-second safety time.
Turn screw V1 (Fig. 7) on the gas valve mixer anticlockwise
slightly.
Once the burner has fired, the next step is to complete the burn-
er's other adjustments.
6.4
Fan adjustment
Modulation is based on variable-speed technology. Combustion
air delivery can be adjusted by varying the motor's speed (rpm).
The proportioning gas train, depending on the pressure detected
in the purging circuit, delivers the right amount of fuel.
Hence the output delivered is adjusted by varying the motor's
speed of rotation. Motor speed can be adjusted by means of the
three Trimmers (Fig. 10).
6.5
Gas valve adjustment
The regulation of the gas delivery is achieved using the two
screws V1 and V2.
To vary the maximum gas delivery turn screw V1.
–
To increase the delivery: turn the screw in anticlockwise di-
rection (unscrew).
–
To reduce the delivery: turn the screw in clockwise direction
(screw up).
To vary the minimum gas delivery act on the screw V2 on the gas
valve.
Remove the protective screws and turn the screw inside with an
allen spanner.
–
To increase the delivery: turn the screw in clockwise direction
(screw)
–
To reduce the delivery: turn the screw in anticlockwise direc-
tion (unscrew)
Definition of the fan adjustments:
The adjustments are made by adjusting the three potentiometers
on the control box.
STAR:
Determines the air in the start phase
(3480 ÷ 5520 rpm)
MIN:
Determines the modulation minimum
(1600 ÷ 2500 rpm)
MAX:
Determines the modulation maximum
(4500 ÷ 6600 rpm)
The adjustment of “MIN” immediately cuts in at the end of the pre-
purging delineated from the opening of the valve and the pres-
ence of the discharge.
The enabling of the maximum modulation with “MAX” happens
every 10 sec from the opening of the valve.
6
Operation
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.
MA
X
ST
A
R
T
MI
N
Fig. 10
D9713
Maximum output
Minimum output
