Honeywell Krom Schroder BCU 580 Technical Information page 61

Parameters
The precondition for this operating mode is that an
external flame supervision device ensures the pres-
ence of the flame in a fail-safe manner indirectly via the
temperature. For this purpose, we recommend a safety
temperature monitor with double thermocouple (DIN
3440). The flame must be monitored again by conven-
tional means (UV sensor or ionization electrode) in the
event of sensor discontinuity or short-circuit, failure of
the safety temperature monitor or power failure.
Only if the temperature at the furnace wall has ex-
ceeded 750°C may voltage be applied to the HT input
(terminal 49) so as to activate High temperature mode.
00 02 03 04
t t
Z FS1
t
SA1
If the temperature in the furnace chamber drops below
750°C, the HT input must be disconnected from the
electrical power supply and the furnace must then be
operated with flame control.
The BCU then responds, depending on setting:
BCU 580 · Edition 11.15l
88
06 07 08
11
46
1
49
9
13
5
4
14
8
41
42
43
t t
SA2 FS2
Parameter 06 = 0
The High temperature mode function is switched off.
Flame control takes place dependent on the setting in
parameter 04 (by ionization electrode, UVS sensor or
UVD sensor).
Parameter 06 = 2 (BCU..D1)
08 01 02
L1
t
Z
ϑ1
HT
t
t
SA1
W
V1
1
The BCU switches off the burner once the HT input has
ϑ2
V2
been disconnected from the electrical power supply
2
and restarts with flame simulation check (recommend-
1
2
ed in the case of UV control with UVS).
t
▼
03 04 06 07 08
t t
t
SA2 FS2
FS1
88
11
L1
46
1
ϑ1
9
49
HT
13
V1
5
1
4
ϑ2
14
V2
8
2
41
42
t
61