Honeywell Krom Schroeder BCU 480 - Page 26

BCU 480 · Edition 03.16l 26
Function
01
02
03
04
08
00
00
08
05
06
07
Switch on BCU 480
Pilot burner start-up
with ϑ1 signal
Safety interlocks (Limits)
In the event of fault signal:
reset
If parameter P15 = 1:
flame simulation check
Wait until
min. burner pause time t
w
has elapsed
If parameter P15 = 0:
flame simulation check
If no flame detected:
max. 3 start-up attempts
or fault lock-out
Start-up position/standby
Safety time t
SA1
running (P22),
ignition in process,
V1 opens and min.
burner on time t
B
starts to elapse (P20)
In the event of flame failure:
restart or fault lock-out
Operating signal
Pilot burner closes
Flame proving period t
FS1
running (P23)
In the event of flame failure:
fault lock-out
Main burner start-up
with ϑ2 signal
Wait until
min. burner pause time t
BP
has elapsed (P21)
If parameter P15 = 0:
flame simulation check
If no flame detected:
max. 3 start-up attempts
or fault lock-out
Safety time t
SA2
running (P22),
V2 opens and
min. burner on time t
B
starts to elapse (P20)
Controlled shut-down
via ϑ signal for
pilot and main burners
If min. burner on time t
B
has
elapsed:
operation signalling contact
opens,
V1 and V2 close,
min. burner pause time t
BP
starts to elapse (P21)
In the event of flame failure:
restart or fault lock-out
Operating signal
Main burner closes
Flame proving period
t
FS2
running (P24)
In the event of flame failure:
fault lock-out
Behaviour of the pilot burner in
the event of flame failure during
operation
If the flame fails during operation,
either an immediate fault lock-out or
a restart occurs. This procedure can
be set via the optical interface (pa-
rameter 12, “Pilot burner restart”).
Start-up of the main burner
without flame signal
If no flame is detected during the
safety time t
SA2
, either a fault lock-
out occurs or up to two further
start-up attempts occur. The re-
quired functions and, if applicable,
the number of start-up attempts
must be specified when ordering
(parameter 11, “Main burner start-
up attempts”).
Behaviour of the main burner in
the event of flame failure during
operation
If the flame fails during operation,
either an immediate fault lock-out or
a restart occurs. This procedure can
be set via the optical interface (pa-
rameter 13, “Main burner restart”).
The air valve can be set to open
with V2 or to be activated ex-
ternally (display
A7
) via param-
eter 30.
The air valve can be set to open
with the operating signal or to
be activated externally (display
A8
) via parameter 30.