AIR DAMPER ADJUSTMENT
Air damper adjustment is performed by acting on the variable pro-
file cam. This operation is performed after having adjusted the
pressure variator and the combustion head.
With the burner on, remove voltage from the servomotor, deta-
ching the fast-on pin located on the electrical control panel, and
release movement by pressing on release 5)(Fig. 9).
Calibrate maximum output, minimum output and intermediate ou-
tputs in this order.
Having completed the adjustment, re-check all calibrations, reset
the electrical connections of the servomotor and secure the adju-
stment screws with the crossways screws.
Modifying air damper tie-rod length
It is recommended to extend the tie-rod when the air gate valve
moves within a reduced angle (air damper at about half travel of
maximum output); this helps avoid giving the cam too curved a
profile.
With the burner off, proceed as follows:
detach ball-joint 2) from lever 1);
unscrew extension 3) a few turns from tie-rod 4);
reconnect the ball-joint to the lever and raise the cam profile
until the air damper index returns to 0 with the servomotor
at 0°.
ELECTRICAL CURRENT TO THE UV CELL
Minimum value for correct operation: 70 µA
If a lower value is read, it may be caused by:
exhausted cell;
low voltage (less than 187 V);
poor burner adjustment.
To measure the electrical current to the cell, use a 100 µA d.c. mi-
croamperometer connected in series to the cell itself, as shown
in the diagram, with a 100 µF 10 V d.c. capacitor in parallel to the
instrument.
ELECTRODE POSITIONING
5041
5 ± 0.2 mm
S7974
Lever 1)
Ball-joint 2)
Extension 3)
Tie-rod 4)
D1143
10
GB
5 ± 0.2 mm
S7973
Fig. 14
Fig. 15
Fig. 16