Reaction To Process Faults - Honeywell BCU 370 Technical Information

Function

3 .6 .1 Reaction to process faults

The BCU 370 reacts differently to process faults in different program steps. If, for example, the signal from air
pressure switch DL drops during pre-purge, 1 flashes on the display and a timeout time of 25 seconds starts to
elapse. If the signal is not applied again, the BCU carries out three further start-up attempts.
Signal
(terminal)
DG (11)
max.
DG (9)
min.
not pending after t
not pending after t
DL (7)
▼
BCU 370 · Edition 01.19
Process fault
Signal status
XX
drops
XX
drops
04
SA1
06
SA2
pending 0
not pending 1
P1
drops
A2
drops
02
drops
03
drops
04
drops
drops 05
06
drops
07
drops
H8
drops
During program step
All
All except t + t
SA1 SA2
t
SA1
t
SA2
"no flow" state check
Operating position check
Pre-purge time
Valve moves to Ignition position
Waiting time
Pre-ignition time
t
SA1
t
FS1
t
SA2
t
FS2
Controller enable waiting time
BCU 370's reaction

4)

4)

4)

 
 
 
 
 
 
 
 
 
 
 
X
X
4
6
0
1
P
2
2
3
4
5
6
7
8
38