PART III: OPERATION
30
Pressure governor is factory-set. The setting values must be locally adapted to machine conditions. Important! Follow the instruc-
tions carefully!
8
.To adjust the
air flow rate in the high flame stage
, loose the
RA
nut and screw
VRA
as to get the desired air flow rate: moving
the rod
T
towards the air damper shaft, the air damper opens and consequently the air flow rate increases, moving it far from the
shaft the air damper closes and the air flow rate decreases.
Note:
once the procedure is perfomed, be sure that the blocking nut
RA
is fasten.
Go on adjusting the burner according to the model (double-stage, progressive, fully-modulating).
Double-stage burners
drive the burner to the low flame stage by means of the
TAB
thermostat;
To change the gas flow rate in order to get an efficient combustion, slacken the nut
DB
and adjust the opening angle of the gas
butterfly valve by rotating the screw
TG
(clockwise rotation increases gas flow, anticlockwise rotation decreases it). The slot on the
butterfly valve shaft shows the opening degree of the valve regardingthe horizontal axis.
Don’t act on DE nuts.
NOTE:
At the end of settings, make sure the locking screws
RA
and
DB
are fully tightened.
Fig. 11
Now adjust the pressure switches.
C V T(V
R
V
VSB
Dungs Multibloc
Siemens VGD..
VR
T
type “A”
type “B”
VR
RA
TR
TR
RA
VR
VR
VR
RA
TR
TG
DB
DE