Honeywell Krom Schroder BCU 580 - Page 67

BCU 580 · Edition 11.15l 67
Parameters
Parameter 78 = 4: two-stage burner 1. Three valves (V1,
V2 and V3) are included for a two-stage-controlled
burner. These are connected to the valve outputs (ter-
minals 13, 14 and 15). The burner can be started with
minimum capacity. When the operating state (program
step 04) is reached, the BCU issues the Enable signal
for the maximum burner capacity to gas valve V2.
BCU 570
µC
V1
V2
V3
14 1513
52
55
54
53
56
47 4858
030201 04
2
1
3
9
14
15
13
5
17-18
t
t
FS1
t
SA1
t
BP
1
Parameter 78 = 5: burner 1 and two-stage burner 2. 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. Valve V2
(terminal 14) can be opened with the operating signal
(program step 08) in order to operate burner 2 at maxi-
mum capacity.
BCU 570..C1F1
µC
V1
V2
V3
V4
14 15 5713
52
55
54
53
56
47 4858
040302 H5 06
2
1
3
9
14
15
13
5
17-18
t
t
FS1
t
SA1
07
t
SA2
08
t
FS2
4
57
8
2
1