BCU 560, BCU 565 · Edition 02.16
70
Parameters > Behaviour during start-up > Burner application
The switchover from flame to menox
®
mode is performed
either immediately or the next time the burner is started de-
pending on the setting made in parameter 64. To switch to
menox
®
mode, the HT signal from the STM (terminal 49) and
the menox
®
signal from a separate control unit (terminal 44)
must be applied to the BCU.
In menox
®
mode (> 850°C), the burner is started with the pre-
ventilation time defined in parameter 28. The air control valve
is set to the "middle" position. No ignition using the transformer
takes place during safety time t
SA1
. The gas valves V1 and V4
are opened at the start of the safety time t
SA1
.
03
02
04
3
1
9
15
4
57
13
49
1
44
t
t
FS1
t
SA1
HT
ϑ
55
53
52
51
47
PZL
M
An IC 40 with operating mode 6 is used as the actuator. The
relevant position is approached via terminals 53 and 55 of
the BCU. The air pressure switch and the position of the IC
are checked by terminals 48, 51 and 52 of the BCU. The BCU
signals a fault if the desired state is not reached within the
time set in parameter 42.
middle
t [s]
high
low
closed
DI 1
DI 2
t [s]
t1
t2
t3
t4
t5
t6
BCU
IC 40 (operating mode 6)
Signal from
terminal
Position
Butterfly valve position
55
53
OFF
OFF
closed
Closed
ON
OFF
low
Closed
OFF
ON
middle
menox
ON
ON
high
Flame
Wiring of BCU/IC 40, see page 81 (Parameter 40 = 2: with