Honeywell Krom Schroder BCU 580 - Page 66

BCU 580 · Edition 11.15l 66
Parameters
Parameter 78 = 2: burner 1 and burner 2. Three valves
(V1, V2 and V4) are included for a modulating burner
with a pilot burner. These are connected to the valve
outputs (terminals 13, 14 and 57). Valves V1 and V4
open to start the pilot burner. Gas valve V2 releases the
gas supply to the main burner.
BCU 570
µC
V1
V2
V4
14 5713
55
54
53
56
0302H1 06 07
2
1
3
9
14
15
13
5
17-18
t
t
FS1
t
SA1
t
SA2
H8
t
FS2
08
t
RF
8
4
57
1
2
Parameter 78 = 3: burner 1 and burner 2 with pilot gas.
In this application, the burner has an additional pilot
gas valve V3. The valves are connected to the valve
outputs (terminals 13, 14, 15 and 57). Valves V1 and
V4 open to start the pilot burner. The burner is started
with a limited ignition capacity using gas valve V3. After
the elapse of the safety time t
SA2
(program step 06),
valve V2 opens (terminal 14). Pilot gas valve V3 is closed
again after the elapse of the flame proving period t
FS2
(program step 07).
For this application, it must be ensured that the flame
proving period (P97) is set to a value ≥ 2 s.
BCU 570..C1F1
µC
V1
V2
V3
V4
14 15 5713
52
55
54
53
56
47 4858
0302H1 06 07
2
1
3
9
14
15
13
17-18
t
t
FS1
t
SA1
t
SA2
H8
t
FS2
08
t
RF
4
57
5
8
1
2
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