Setting Of The Air Damper Servomotor; Commissioning - Riello 40 GS20/M - HEATER Manuel D'entretien

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
required;
√ 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.
G
2546001
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 lit-
tle, 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
factory. DO NOT INCREASE THAT VALUE : the burner can be damaged.
Min output
kW
22
26
30
35
43
47.8
48.9
(see fig. 2)
Fig. 2
D4047
Gas pressure on
combustion head
mbar ( )
G
1.4
2.4
3.2
3.7
3.2
4.6
5.1
9
GB
Red
Blue
Orange
Air damper
adjustment
Set point
4
5
6
8
5.25
7
max