BCU 480 · Edition 06.07
37
Fault lock-out or restart, main burner
5 .6 .4
This parameter determines whether the BCU starts a one-
off restart or performs an immediate fault lock-out for the
main burner after a flame failure (see also Project planning
information).
Immediate fault lock-out following flame failure
Parameter 13 = 0: Main burner fault lock-out.
08
t
t
SB
08
9
12
V1
1
14
V2
2
2
16-17
1
24
21
88
4
5
1
7
18-19
28-29
ϑ
1
ϑ
2
After a flame failure, the burner control unit performs a fault
lock-out within the safety time during operation t
SB
. This in-
volves disconnecting the power from the gas valves and the
ignition transformer. The fault signalling contact closes, the
display blinks and shows the current program status (see
table “Program status and fault messages”).
After a fault lock-out, the burner control unit can be reset,
either with the button on the front panel or using an external
button. Several burner control units can be reset in parallel
using the external button.
The BCU cannot be reset by mains failure. The fault signalling
contact does, however, open as soon as the mains voltage
fails.
See also “Behaviour of the air valve in the event of a fault
lock-out”.
Parameters > Behaviour during operation
t
