PFU 780 · Edition 02.12l
33
Parameters
4 .5 .4 Burner start-up attempts
Pilot burner
Parameter 10
This indicates the number of possible start-up attempts
of the burner.
In accordance with EN 746-2, three start-ups are per-
mitted in specific cases in the event of flame failure
during start-up, if the safety of the installation is not
impaired. Note the requirements of the Standards!
If no flame is detected during start-up, either a fault
lock-out is performed or further start-up attempts in
accordance with EN 746-2 occur.
Pursuant to NFPA 86, only one start-up attempt is per-
mitted in the event of flame failure during start-up. For
units approved by FM Approval (see type label), it is
only possible to select one start-up attempt.
1 start-up attempt
Parameter 10 = 1
t
SA
t
Z
02
00
t
02
26a
16c
18e
2c–4c
88
10e
26e
30a
28c
2e–4e
V1
V2
ϑ
1
If no flame forms during start-up, a fault lock-out is
performed after expiry of time t
SA
. The display blinks
and shows the cause of the fault.
2 or 3 start-up attempts
Parameter 10 = 2, 3
t
SA1
t
Z
02
00
t
t
SA1
t
Z
26a
16c
18e
2c–4c
88
10e
26e
30a
28c
2e–4e
V1
V2
ϑ
1
1
If several start-up attempts are set and if the PFU de-
tects a flame failure during start-up, it closes valve V1
after the safety time t
SA1
has expired and attempts to
start up again. After the last programmed start-up at-
tempt has been completed, the burner control unit con-
ducts a fault lock-out. The display blinks and shows the
cause of the fault.