Air Pressure Switch; Burner Start-Up Cycle - Riello 40 FS20 CV 569 T Montage- Und Bedienungsanleitung

4.3 AIR DAMPER SETTING,
The regulation of the air-rate is made by adjusting the air damper (1),
after loosing the screws (2). When the optimal regulation is reached,
screw tight the screws (2). 
4.4 COMBUSTION CHECK
CO It is advisable to not exceed 10% of CO
2
order to avoid the risk that small changes of the adjustments
due, for instance, to draught variation, may cause combustion
with insufficient air and, consequently, with formation of CO.
CO Not exceeding 100 mg/kWh (93 ppm).
IONIZATION CURRENT
The minimum current necessary for the control
box operation is 3 µA. 
The burner normally supplies a higher current
value, so that no check is needed. However, if
you want to measure the ionization current, you
must open the connector fitted to the red wire
and insert a microammeter.

4.5 AIR PRESSURE SWITCH

The air pressure switch is set after all other adjustments have been made. Begin with the switch at the
lowest setting. With the burner working at the minimum output, adjust the dial clockwise, increasing its
value until the burner shuts down. Now reduce the value by one set point, turning the dial anti-clockwise.
Check for reliable burner operation, if the burner shuts down, reduce the value by a half set point.
Attention:
To comply with the EN 676 standard, the air pressure switch must operate when the CO value exceeds 1%
(10,000 ppm). To check this, insert a combustion analyser in the flue, slowly reduce the burner air setting and
verify that the burner shuts down by the action of the air pressure switch before the CO value exceeds 1%.

4.6 BURNER START-UP CYCLE

Operation without continuous ventilation
Thermostat
Motor
Ignition transformer
Valves
Flame
Lock-out
max. 2s
Operation with continuous ventilation
Thermostat
Motor
Ignition transformer
Valves
Flame
Lock-out

 Heat request beginning
Warning: the heat request is independent of the engine ventilation function.
- when flame-failure occurs during working, shut down takes place within one second.
3216
(see Fig. 3)
40s
40 + 2s

 Heat request end
Fig. 3
(natural gas) , in
2
Terminal board
of control-box
10
Lock-out, due to ignition failure
max. 2s
Lock-out, due to ignition failure
7
GB
2
Connector
D5006
40s 3s
40 + 2s 3s
1
2
D5231
Probe
D4172
D7278