
BCU 560, BCU 565 · Edition 02.16
23
Function
3 .2 BCU 560 program sequence
Parameters 48 and 49 = 0: High/Low control during operation,
cooling in standby
Example of application, see page 8 (Two-stage-controlled
Switch on BCU 560
▼
In the event of fault signal: reset
▼
00
Safety interlocks
Start-up position/standby
▼
Flame simulation check
▼
P0
External actuation of the air valve for purging
▼
A0
External actuation of the air valve for cooling
▼
H1
Start-up with
ϑ
signal
▼
Wait until the running time has elapsed (P42)
▼
02
Safety time 1 t
SA1
(P94) running,
ignition in process,
valves for 1
st
gas stage open.
▼
If no flame detected:
max. 3 start-up attempts (P07)
or fault lock-out
▼
03
Flame proving period 1 t
FS1
running (P95)
▼
In the event of flame failure:
fault lock-out
▼
04
Operation signalling contact closes,
valve for 2
nd
gas stage opens and
min. operating time t
B
starts to elapse (P61)
▼
In the event of flame failure:
restart or fault lock-out
▼
A4
External actuation of the air valve for capacity control
04
Controlled shut-down via
ϑ
signal
▼
00
If min. operating time t
B
has elapsed:
operation signalling contact opens,
gas valves close and
running time (P42) starts to elapse