Bcu 480 Program Sequence - Honeywell Krom Schroeder BCU 480 Manual

Function
Switch on BCU 480
In the event of fault signal:
reset
Safety interlocks (Limits)
00
Start-up position/standby
If parameter P15 = 1:
flame simulation check
01
Pilot burner start-up
with ϑ1 signal
Wait until
min. burner pause time t
has elapsed
If parameter P15 = 0:
flame simulation check
02
Safety time t
running (P22),
ignition in process,
V1 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
BCU 480
If the air valve control is used,
the unit offers the following ad-
ditional functions:
In start-up position, the air
valve can be opened for cool-
ing
Using parameter 31, it can be
determined whether the air
valve can be activated exter-
nally during start-up (display
A1
w
The air valve can be set to open
SA1
together with V1 (display
via parameter 30.
B
A0
(display ).
A
).
A2
)

3 .4 BCU 480 program sequence

Normal start-up
If an "old" fault is still being signalled after
switching on, it will be necessary to reset this
first.
The safety interlocks (terminal 5) must be
closed and the burner control unit must be
switched on.
The BCU 480 conducts a self-test when in
the start-up position (the burner is switched
off). If it does not determine a malfunction
of the internal electronic circuitry or of the
flame sensors, the burner can be started.
The pilot burner start-up is activated via the
signal input "Start-up signal ϑ1" (terminal 4).
Once the start-up signal ϑ1 has been applied,
the BCU 480 opens valve V1 and ignites the
burner. The ignition time t is constant. If a
Z
flame is detected during the safety time t
the flame proving period t
FS1
safety time t has elapsed.
SA1
If the pilot burner has been started success-
fully and its flame has stabilized, the burner
control unit issues the Enable signal for main
burner operation. The operation signalling
contact for the pilot burner (terminals 16/17)
closes.
▼
,
SA1
starts after the
24