PFU 780 · Edition 02.12
32
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 permitted in
specific cases in the event of flame failure during start-up, if
the safety of the installation is not impaired. Note the require-
ments 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 permitted 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 detects 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 attempt has been completed, the
burner control unit conducts a fault lock-out. The display blinks
and shows the cause of the fault.
Parameters > Behaviour during start-up