2861
11
GB
6.3
SETTING OF THE AIR DAMPER SERVOMOTOR,
(see fig. 11)
CAM II
assures the fully closed position of the air
damper, when the burner is shut down (stand by).
It is adjusted by the factory at 0°.
DO NOT ALTER
.
CAM III
adjusts the air damper for the ignition
and for the minimum output. It can be adjusted
whilst it is being put into service.
CAM IV
is integral
with
CAM III
.
I
limits the rotation at the maximum output. It is ad-
justed at 90° by the factory.
DO NOT INCREASE
THAT VALUE
: the burner can be damaged.
The servomotor only follows adjustment of
CAM III
when the cam’s angle is reduced.
If the cam’s angle needs increasing, you must first increase the servomotor angle with the “increase output
(+)
”
key, then increase the angle of
CAM III
and, lastly, return the servomotor to the MIN output position with the “de-
crease output
(-)
” key.
Where necessary,
CAM III
can be adjusted by removing cover (1), which is snapped on, as illustrated in fig. 12,
removing the relevant key (2) from inside, and inserting it in the slot on
CAM III
.
S7025
For the burner to operate over a given output, in the model
type 917M e 918M, you must remove the blank deadening to
free the supplementary slits of the air inlet on the cover, as
illustrated in figure 10.
TYPE
Thermal power - kW
917M
> 140
918M
> 200
A
Fig. 10
Fig. 11
D4438
STAND-BY
CAM II
FIRST STAGE
CAM III
SECOND STAGE
CAM I
D4439
Fig. 12
