DE DIETRICH ELITEC DTG 130 Eco.Nox - Manual (Page 12)

12
DTG 130 Eco.NOx 01/02/11 - 300002915-001-E
3.4 Operating principle
577 DBC safety box
„
Operating principle
The ignition and burner surveillance sequences are ensured by the
safety box.
„
Normal operating cycle
If heating is required, the boiler thermostat TCH closes the contact.
The ignition transformer TA integrated into the safety control box and
the ignition burner valve VBA (supply to the ignition burner) are
switched on.
Gas from the ignition burner is ignited by the ignition electrode and
within the time interval ts; a minimum current of 0.3 µA appears on
the ionization sensor SF and the gas valve regulation flap (supplying
the principal burner) opens.
„ Operating cycle on safety (start up without flame
signal)
If a flame is not detected before the safety time ts, the box makes 2
more ignition attempts. If, at the end of the last attempt, there is still
no flame signal, the box goes into safety and the safety indicator
comes on. To restart the heater, press the reset button on the safety
box.
If there is a loss of flame in normal operation, the box automatically
repeats the start up sequence.
„
Resetting
The box is reset after going into safety by pressing the reset button.
If the reset button does not work, wait at least 15 seconds before
trying a second time.
The box may be on safety on its first start up. Press the resetting
button of the burner.
If the reset button is pressed in normal operation, the gas valves
close and the box starts a new ignition sequence.
A B
ts
TCH
VA
TA
SF
VBP
TAF
VBA
8518N001
A A
1
C
1
C E
ts
TCH
VA
TA
SF
VBA
VBP
8518N044
A
2 C
2
TAF
ts ts