Servomotor Adjustment; Combustion Air Adjustment - Riello RLS 1000/M MX Installation, Use And Maintenance Instructions

6.8

Servomotor adjustment

The servomotor (Fig. 35) simultaneously adjusts, through driving
gears, the output and pressure of the air, and the flow rate of the
fuel being used.
It is equipped with adjustable cams which operate as many
switches.
Cam I: limits the servomotor limit switch on the
maximum position (about 130°) (light oil
operation).
Cam II: limits the servomotor limit switch at the 0°
position. With the burner off the air damper is
completely closed (light oil and gas operation).
Cam III: regulates the minimum modulating output.
Position 30° is factory set (minimum light oil
operation).
Cam IV: limits the servomotor limit switch at the
maximum position (about 130°) (light oil
operation).
Cam V: regulates the minimum modulating output.
Factory set at position 30° (gas operation).
Remaining cams:not used
Lever 7: Servomotor release
6.9

Combustion air adjustment

The fuel/combustion synchronization is made by means of a
servomotor connected to two variable profile cams, which act on
the outlet air damper 1)(Fig. 36) and gas damper 2) and on the
combustion head by appropriate levers.
It is advisable, to reduce the loss and for a wide calibration field,
to adjust the servomotor to the maximum of the output used, the
nearest possible to the maximum opening (130°).
On the gas butterfly valve, fuel step according to the burner
output required, with servomotor completely open, is carried out
by the pressure stabiliser placed on the train.
D11563
2
Start-up, calibration and operation of the burner
1
S8446
The values indicated in Tab. O and Tab. P can be a reference for
a good combustion calibration.
EN 676
Theoretical max.
CO
GAS
0 % O
G 20 11.7
G 25 11.5
G 30 14.0
G 31 13.7
EN 267
Theoretical max CO
0 % O
2
15.2
Fig. 36
31 GB
7
Air excess
Max. output Max. output
  1.2
CO % Calibration
2
2
 = 1.2
2
9.7
9.5
11.6
11.4
Air excess
Max. output Min. output
  1.2
CO % Calibration
2
2
 = 1.2
12.6
Fig. 35
CO
  1.3
mg/kWh
 = 1.3
 1000
9
 1000
8.8
 1000
10.7
 1000
10.5
Tab. O
CO
  1.3
mg/kWh
 = 1.3
 1000
11.5
Tab. P
20148180