Honeywell Krom Schroder PFU 780 Technical Information page 36

Parameters
Restart following flame failure
Parameter 12 = 1:
Restart following flame failure.
1x
04 01
>2 s
t
t
SB
Z
t
t
SA1
W
If the PFU detects a flame failure after a minimum op-
erating time of 2 s, the valves are closed and the opera-
tion signalling contact is opened within time t
The burner control unit now attempts to restart the
burner once. If the burner does not function, a fault
lock-out occurs. The display blinks and shows the
cause of the fault.
In accordance with EN 746-2, a restart may be con-
ducted only if the safety of the installation is not im-
paired. Restart is recommended for burners which oc-
casionally display unstable behaviour during operation.
The precondition for a restart is that activation of the
restart allows the burner to restart as intended (in all
operating phases). In this case, it must be ensured that
the program sequence started by the PFU matches the
application.
PFU 780 · Edition 02.12l
03 04 88
30a
26e
10e
1
28c
26a
1
16c
V1
2c–4c
1
2e–4e
t
t
FS1
.
SB
36