3126
8
4.5 AIR DAMPER ADJUSTMENT
The air damper is set in factory.
This regulation is purely indicative. Each installation
however, has its own unpredictable working condi-
tions: actual nozzle output; positive or negative
pressure in the combustion-chamber, the need of
excess air, etc. All these conditions may require a
different air damper setting.
The air setting is performed by mean of two inde-
pendent dampers (see fig. 10 and 11).
MAIN AIR DAMPER (A) - fig. 10
The main air damper can be set in either of two
positions. To set the positions of the damper, pro-
ceed as follows:
Remove the secondary air damper (
B
) loosing
the screws (
1
).
Loosen the screw (
2
) and rotate the main air
damper (
A
) to the required position.
Retighten the screw (
2
) and put back the second-
ary air damper (
B
).
SECONDARY AIR DAMPER (B) - fig. 11
The purpose of this damper is to perform a fine-tun-
ing of the inlet air.
Tuning of this device is possible acting of the
screw (
3
).
4.6 FUEL HEATING
In order to obtain smooth starting and operation
across its output range the burner is fitted with an
electric resistance, which heats up the light oil in the
nozzle line. This resistance is energized when the
thermostat calls for heat and after a delay of
approximately two minutes depending on room
temperature, the motor will start. The resistance
remains energised during working and cuts out
when burner shuts-down.
4.7 BURNER START-UP CYCLE
Lock out is indicated by a lamp on the control box (3, fig. 1, page 1).
B
1
2
A
E9281
B
3
E9172
Fig. 10
Fig. 11
Secondary air damper (B)
Main air damper (A)
D4546
~
12s
~
12s
~
5s
Lock-out due to failure to light
B
Normal
Thermostat
Motor
Flame
Lock-out lamp
Resistance
Valve
Ignition transformer
B
