5.2 SETTING OF THE AIR DAMPER SERVOMOTOR
STAND-BY
FIRST STAGE
SECOND STAGE
NOTE
The servomotor is equipped with two micrometric
screws for a careful setting of CAM II (Blue) and
CAM III (Orange).
5.3
COMMISSIONING
After completing both the electrical and gas valve connections, set the minimum air and the gas pressure
switches at minimum value; the maximum air pressure switch must be first set at maximum value. These will
be adjusted only at the end of commissioning procedure.
Connect a manometer to the gas pressure test point situated on the burner.
1) For guidance the following table shows:
– the capacity required by the application;
– the minimum firing rate achieved for each capacity;
– approximate gas pressure measured at the combustion head, depending on the maximum capacity re-
quired;
– the setting for the air damper.
Thermal power
kW
42
60
81
106
81
159
170.3
( ) These values refer to a combustion chamber with 0 [mbar] back pressure at maximum output.
2622
CAM II (Blue)
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 (Orange)
CAM III adjusts the air damper for the ignition and for the minimum output. It is
set at 20° by the factory. Do not decrease that value; it can be increased a little,
following the need of the application.
CAM I (Red)
CAM I limits the rotation at the maximum output. It is adjusted at 90° by the fac-
tory. DO NOT INCREASE THAT VALUE: the burner can be damaged.
Min output
kW
22
26
30
35
43
47.8
48.9
10
(see fig. 2)
Fig. 2
D4047
Gas pressure on
combustion head
mbar ( )
1.4
2.4
3.2
3.7
3.2
4.6
5.1
GB
Red
Blue
Orange
Air damper
adjustment
Set point
4
5
6
8
5.25
7
max