WORKING CYCLE
SINGLE-STAGE:
When switched on the burner motor starts and the 15-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 3 seconds (post-ignition phase) the inter-electrode arc is switched off. If the flame fails to appear
within 10 seconds of the end of pre-ventilation the burner is shut down. 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 (20) and/or by the room thermostat indicator. Burner restart is effected by
pressing the reset button (20).
TWO-STAGE:
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-electrode arc is switched off. If the flame fails to appear
within 10 seconds of the end of pre-ventilation 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 Kg/cm
stage) to 18 Kg/cm
2
re-ignition sequence begins. Burner shutdown is indicated by the boiler system warning light (20) and/or
by the room thermostat indicator. Burner restart is effected by pressing the reset button (20).
ECO 15
ECO 20
ECO 15/2
ECO 20/2
Necessary input signals
Output signals
(second stage). If the flame accidentally goes out during routine operation an automatic
IGNITION CYCLE
IGNITION FAILURE
t1 Pre-ventilation and pre-ignition
t2 Post-ignition
t3 Max safety time
32
2
(first
Fig. 5