Honeywell Krom Schroder PFU 780 Technical Information page 14

or fault lock-out
Function
03
Flame proving period t
running (P23)
In the event of flame failure:
restart or fault lock-out
04
Operating signal
Pilot burner closes
In the event of flame failure:
restart or fault lock-out
05
Main burner start-up
with ϑ2 signal
Wait until
min. burner pause time t
has elapsed (P21)
If parameter P15 = 0:
Flame simulation check
06
Safety time t running (P24),
SA2
V2 opens and
min. combustion time t
starts to elapse (P20)
If no flame detected:
next start-up attempt (P11)
or fault lock-out
PFU 780 · Edition 02.12l
The air valve can be set to open
FS1
together with V1 (display
via parameter 30.
The air valve can be set to open
together with V1 (display
via parameter 30.
The air valve can be set to open
together with V1 (display
via parameter 30.
BP
The air valve can be set to open
with V2 or to be activated ex-
B
ternally (display
eter 30.
The PFU coordinates the correct
program run for the pilot and main
burners. The main burner can be
A3
)
started via the signal input "Start-
up signal ϑ2" (terminals 14a/14c) if
required.
Once the start-up signal ϑ2 has
been applied (terminals 14a and
14e), the PFU 780 opens valve V2.
A4
)
The main burner is ignited by the
pilot burner.
If a flame is detected during the
safety time t
period t
time t
A5 )
burner has been started success-
fully and its flame has stabilised,
the operation signalling contact
(terminals 6a/6e) closes.
Start-up of the pilot burner
without flame signal
If no flame is detected during the
safety time t
out occurs or up to three further
start-up attempts occur. (Param-
A6
) via param-
eter 10, "Pilot burner start-up at-
tempts").
, the flame proving
SA2
starts after the safety
FS2
has elapsed. If the main
SA2
, either a fault lock-
SA1
▼
14