Honeywell BCU 370 - In the Closed Position

BCU 370 · Edition 01.19 25
Function
3.2.4 Start-up without pre-purge,
butterfly valve waits in the Closed
position
Parameter 18 = 0, parameter 28 = 1
If a fault from the preceding operat-
ing cycle is still being signalled after
switching on, it will be necessary
to reset this first. Once the start-
up signal (ϑ) has been applied, the
switch-on delay t
E
starts to elapse.
Afterwards, the butterfly valve
moves from the Closed to the Open
position and then to the Ignition po-
sition. During the fan run-up time
t
GV
which follows, the fan starts
with the butterfly valve being set to
Ignition position.
After the waiting time t
W
, the BCU
activates pre-ignition t
VZ
and then
opens valves V1 and V2 for the
pilot burner. The ignition time t
Z
is
constant. After the flame proving
period for the pilot burner t
FS1
, valve
V3 opens to ignite the main burner.
▼
H0
04
05
06
07
08
00
00
H0
01
A1
A0
A2
03
H8
08
P9
02
Switch on BCU 370
Start-up with ϑ signal
In the event of fault signal: reset
Fan run up time t
GV
(P20)
Switch-on delay time t
E
running (P22)
Start-up position/standby
Start-up position/standby
Controlled shut-down
via ϑ signal
Flame proving period t
FS1
running for burner/pilot burner (P13)
Safety time t
SA1
running for
burner/pilot burner (P12),
V1 and V2 open
Butterfly valve moves to Open position
Butterfly valve moves to Closed position
Flame proving period t
FS2
running for main burner (P15)
Safety time t
SA2
running for main burner (P14),
V3 opens
Butterfly valve moves to Ignition position
Pre-ignition time t
VZ
running (P21d
Ignition activated
Controller enabler signal delay time t
RF
(P29)
Controller enable signal
Post-purge time t
PN
running (P19)
If parameter P27 = 0:
V2 is switched off
Waiting time t
W