Honeywell Krom Schroeder BCU 480 Manual page 25

or fault lock-out
Function
03
Flame proving period t
running (P23)
In the event of flame failure:
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 (P22),
SA2
V2 opens and
min. burner on time t
starts to elapse (P20)
If no flame detected:
max. 3 start-up attempts
or fault lock-out
BCU 480 · Edition 03.16l
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
parameter 30.
The BCU coordinates the correct pro-
gram run for the pilot and main burn-
ers. The main burner can be started
A3
)
via the signal input "Start-up signal
ϑ2" (terminal 21) if required.
Once the start-up signal ϑ2 has been
applied (terminal 21), the BCU 480
opens valve V2. The main burner is
A4
)
ignited by the pilot burner.
If a flame is detected during the safe-
ty time t
t
FS2
has elapsed.
If the main burner has been started
A5 )
successfully and its flame has stabi-
lized, the operation signalling contact
(terminals 28/29) 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 two further start-
up attempts occur. The required
A6
) via
functions and, if applicable, the
number of start-up attempts must be
specified when ordering (parameter
10, "Pilot burner start-up attempts").
▼
, the flame proving period
SA2
starts after the safety time t
, either a fault lock-
SA1
SA2
25