Working Cycle - Ferroli SUN G 20 Notice D'installation Et D'entretien

WORKING CYCLE

When switched on the burner motor starts and the 13-second pre-ventilation phase begins.
During this phase the ignition transformer comes on and the inter-electrode arc is generated.
Once pre-ventilation is over the fuel on-off valve opens and the fuel starts flowing out of the
nozzle thus igniting a flame. After another 15 seconds (post-ignition phase) the inter-electro-
de arc is switched off. If the flame fails to appear within 10 seconds of the end of pre-venti-
lation the burner is shut down. At the end of the post ignition time, the servomotor of the air
lock is switched ON, thereby causing the air lock to open. This will supply the fuel selenoid
valve fitted on the pump, so that gas air pressure at the nozzle will increase from 10 bar (first
stage) to 18 bar (second stage). If the flame accidentally goes out during routine operation
an automatic re-ignition sequence begins. Burner shutdown is indicated by the boiler system
warning light and/or by the room thermostat indicator. Burner restart is effected by pressing
the reset button.
1
2
t 13 sec
1
Necessary input signals
Output signals
t 10 sec
3
t 15 sec
2
t1 Pre-ventilation and pre-ignition
t2 Post-ignition
t3 Max safety time
t 10 sec
3
t 13 sec
1
UK
27