20019893
26
GB
Start-up, calibration and operation of the burner
5.4
Servomotor
The servomotor gives simultaneous regulation of the air damper
through the variable cam profile 4)(Fig. 29) and the gas butterfly
valve.
It rotates by 90° in approx. 24 s.
The factory settings must not be changed for the first firing, just
check that they comply with the details below.
To open the servomotor, remove the screws and pull the cover out-
ward (Fig. 30).
Key (Fig. 29)
1
Servomotor
2
Gas butterfly valve
3
Gas butterfly valve index
4
Air profile cam
5
Low fire air adjustment screws
6
High fire air adjustment screws
7
Opening for access to screw 5-6
Fig. 32 shows how the servomotor is released to manually check
there is no binding though its motion.
1
2
3
4
6
5
7
Fig. 29
D10955
Fig. 30
D2277
WARNING
The blue wire and the black wire define the di-
rection of the rotation. Do not reverse the wires!
In case of servomotor replacement, connect
black wire to therminal 12 and blue wire to ther-
minal 21 as indicated in Fig. 31.
WARNING
Don’t release the button indicated in Fig. 32: the
syncronization of the cams made in factory
would be changed.
Fig. 31
S8200
Blue wire
Black wire
12
21
Fig. 32
D2585
NO
YES
